I’ve been talking to one of the editors at Taunton about trying to write an article about trusses. And he suggested posting here to see if you guys could come up with something that might help in the writing of the article.
What we’re thinking about doing is an article called the “Top Ten Truss Travesties”. Or “How your truss job can go to hell in 30 seconds or less”. (by Henry Gibson)
It would be patterned sort of like the recent article on Roof Goofs in issue #172. (The one with synthetic decking on the cover) The idea is to highlight some common problems that occur with trusses.
I know that problems with trusses are EXTREMELY rare. So most of you will likely not have anything to contribute. But maybe some of you have heard a story about something that’s gone wrong, and may be able to provide some info about the situation.
If you want an example of what I mean, I’d be happy to coem up with one.
Sex is not the answer. Sex is the question. The answer is yes.
Replies
Hey Boss,
How about an article on switching to trusses. Truss roof 101.
I've never used trusses and wouldn't know where to even start (almost all the roofs here are flat or mostly flat with some shed or peaked sections so they all get stick framed). Maybe trusses on the shed and peak sections would be the way to go?
I'd guess there are lots of other guys out there like me -- need the basics.
A sidebar could focus on truss travesties.
I'd read it.
"Let's get crack-a-lackin" --- Adam Carolla
Edited 5/2/2006 9:07 am ET by philarenewal
I thought "Heko" was that new Norwegian singer?
Heko is actually an ancient name taken from the Bible, in the book of Hezakiah. It's meaning is top secret - Known only to those in the truss industry.I could tell you what it means, but then I'd have to kill ya.
When you open a new bag of cotton balls, is the top one meant to be thrown away?
The only truss problem I ever had was that it didn't fix my hernia...
(Good luck with the article BH, sounds like a great idea).
"How about an article on switching to trusses. Truss roof 101."
I can run that by the editor and see what he thinks. I don't know if they would like the idea or not.
They might look at it as being a sort of "sales" article - Trying to convince people to use trusses.
I let the editor know about this thread, so maybe he'll respond and let us know what he thinks.
Comparisons are as bad as clichés
Edited 5/2/2006 9:32 am by BossHog
I think you should focus on three things: trusses for complex jobs, cost comparisons, and detailing for ceiling finish.
Forget the mistakes stuff. I'm sorry, but it is not good material for an article. Mistakes can happen and do happen in every aspect of housebuilding. The only reason everybody gets their hair on fire about truss errors is because they always throw a wrench into the rush to get dried in.
As regards trusses for complex jobs, show not only that complex jobs can be trussed, but that the use of trusses can eliminate the kinds of postdowns and bearing wall stuff required in complex stickbuilt roofs.
Show how the kinds of multi-hip roofs on the McMansions that Dieselpig and Tim Uhler are stickframing are addressed with trusses. Do a serious cost workup to show how a truss package cost compares to the cost of all the sawn lumber and LVLs to accomplish the exact same apples to apples thing.
Then compare labor manhours to erect the same roof, stick versus truss, and ring up the grand totals.
Show how lay on dormer frames are done with stepdown sets. Show how the new Simpson clips make fastening easy.
Show a big hip set being erected on the ground, where things go together easily and rapidly, without ladders or climbing, then show the whole thing flying into place with a crane.
Go inside and show how tray ceilings are done, vaults with hips, boxups for groin vaults, etc. Many people don't know how detailed the underside of a trussed roof can be.
Mention bracing, but don't get heavily into detail, please.
Finally, show what kinds of blocking, strapping, underframing, etc., are required to get the underside of a trussed roof ready for (drywall) finish, and go into some detail on the proper application of truss-to-wall clips, sheetrock fastening and corner taping, etc.
"Forget the mistakes stuff. I'm sorry, but it is not good material for an article."
We've tossed around a lot of ideas and that's what they're asking me to write about. I think it will work, as long as it points out ways to AVOID the problems.
"...compare labor manhours to erect the same roof, stick versus truss, and ring up the grand totals."
Again, you're getting into selling trusses over stick framing. I don't think they'll like that. Even though trusses are obviously vastly superior. (-:
"Mention bracing, but don't get heavily into detail, please."
Erection bracing (or lack of it) was one of the things I thought about mentioning. Having a set of trusses fall over isn't something you want to be involved in. And it happens all too often.
"...proper application of truss-to-wall clips..."
Failing to plan for truss uplift is another thing I had thought of including.
I've got a way with women - Way out of line
Boss, re the cost comparo, I am not proposing selling trusses at all over stick framing, just providing useful information that many people probably don't know. People make wrong assumptions all the time, and a comparison like the one I speak of would be very informative. Just the facts, ma'am.
Truss packages can get expensive, as you well know, and the cost of a truss package can often greatly exceed the cost of a pile of sawn lumber and LVLs to frame a roof. But to get down to a true comparison, one needs to do all the numbers, as for ceiling joists, labor, etc.
Furthermore, many of the roof cutters out there consider themselves high priests and wizards, and don't know how a complex roof can be done with a truss package.
"Mention bracing, but don't get heavily into detail, please."
"Erection bracing (or lack of it) was one of the things I thought about mentioning. Having a set of trusses fall over isn't something you want to be involved in. And it happens all too often. "
When I was a yung'un, someone built a bungalow next door. They put up all the trusses, and the only "bracing" was a 1x4 run along the top of the trusses from one end of the house to the other.
Needless to say, the next day, all of these trusses were still nicely spaced, but were now laying down at about a 30 degree angle (like this: //////////, only more so).
Their solution? A jeep with a winch. Tied onto the end truss, and pulled them back to vertical. Fine Homebuilding, indeed.
Again, you're getting into selling trusses over stick framing.
No more so than the multiple ICF articles that have been in the mag... or the PEX articles, or any number of other articles.
Seems to me that they could do a 'roof' issue. Have a big article on rafters, a big article on trusses, and then smaller articles on sheathing and roofing options (copper, asphalt, slate, etc).
The rafter/truss issues aren't selling one idea or the other, just giving information.
jt8
"The difference between greatness and mediocrity is often how an individual views a mistake..."-- Nelson Boswell
Not selling? My point exactly.
Maybe it's just me, but I want to know relative costs whenever looking at a product or system in any aspect of housebuilding. I need the numbers to be able to know how I feel about looking further.
I'm sure one could develop an article for FH called "Ten Mistakes to Avoid When Building With Trusses," but that really doesn't interest me much. I probably have made 8 of the 10 so far and have learned from them and moved on.
But I don't think FH furthers its image or satisfies its readership with a "mistakes" article. A "ten goofs" piece seems kinda bush league to me.
"Engineered Truss Packages for Complex Roofs" sounds much more like something I would read and enjoy. All this stuff about lacing, bracing, layout, don't-load-full-bunks-of-sheathing-up-there, yadda, yadda, yadda . . . it just make me want to say, "hey dummy, it is an $18,500 package, why don't you just read the instructions!"
"I probably have made 8 of the 10 so far and have learned from them and moved on."
We all know you've made plenty of mistakes.
(-:
But not everybody has. There are new guys entering the trades every day. Why not keep them from making some of the mistakes? And what about the DIY people who might read FHB to learn before they build their own house?
BTW - Was it you who mentioned the cost of stick framing vs. components?
A few years back, the WTCA sponsored something called "Framing the American Dream". They basically built 2 identical houses side by side in a parking lot - One with components and one with stick framing.
If you're interested, you can download a PDF file of the propaganda about the event here:
http://www.sbcindustry.com/projects/woodtruss/images/publication_images/fad.pdf
Naturally, it showed that using components was cheaper. Even if you assume that the test was deliberately skewed to favor components, I figure it means that it costs basically the same.
It would be interesting to talk to the guys who framed each house and see what they thought when they were done...
Bumpersticker: I majored in liberal arts. Will that be for here or to go?
I'm sorry, Boss, but that article doesn't boil things down to cost. It only gives me material usage in board feet, and manhours for installation.
For the only house I ever did with trusses that was originally designed as stickframed, the truss package, while I am sure it had less board footage than the sawn lumber required to stickframe it, cost more. Where we saved money was on the labor, and it was enough to offset the truss cost premium and then some. Plus, it saved us schedule time, and probably some disposal costs.
As for the new guys entering the trades every day, my guess is that they are neither subscribing to FH, nor buying it off the rack.
Here is the original prototype of the house I mentioned above, complete with its stickframed roof.
View Image
And here is the copy I did, all framed with roof trusses. While the roof's top shapes are simple, the underside ceilings are not, and the trusses frame it all.
View Image
Edited 5/3/2006 12:12 pm ET by Gene_Davis
"I'm sorry, Boss, but that article doesn't boil things down to cost."
Page 4 has costs.
But realistically - The only thing I see as making a difference is the man-hours of labor. Labor costs vary a great deal from one region to the next, and go up all the time. This article only used a labor cost of $20 per hour, so it's really dated.
The costs for the framing lumber and truss package would also have to be goten on a per-job basis.
I suppose if you were into "green" building you could use the savings in lumber as a selling point for using trusses.
Don't go near the water until you learn how to swim
I reviewed page 4 and did not see enough detail to suit me. They seemed to have lumped roof truss components with all the other components (walls and floors) for the project.
Since we are talking roof trusses here, and only roof, I would want to see how a truss package cost, plus any non-included lumber and accessories, plus labor, crane, etc., then disposal of scrap, packaging, strapping, etc., would compare to the same thing as stickframed, including all the ceiling joist stuff, so as to get down to "apples to apples."
I think that often all that stuff that goes on in a stickframed job to get the underside ready for drywall, gets overlooked by those seeking to compare truss costs to stick.
I was an Archy student turn contractor and have read FHB since I started. Always valued the info. know lots of other young guys who do the same. Don't discredit the newbies. I'm 15 years in the trades now and here I am still reading FHB. Maybe I'll contribute someday for the new guys.
The reason less people enter the trades and stay is because the veterans are too tight with the info. pass it on, train the next generation. they need you.
<<But I don't think FH furthers its image or satisfies its readership with a "mistakes" article. A "ten goofs" piece seems kinda bush league to me.>>
Gene - Your posts are getting off-topic, and I don't want to indulge too much (though I'm tempted) but I will say that "Built wrong from the start" [aka: top ten building blunders] and "10 Roof Goofs" both scored very high according to our reader surveys.Justin Fink - FHB Editorial
Dang, you DID add a lot of comments today.
Regarding the field modifications that PaulBinCT mentioned - I think that's a non-starter for an article.
Field repairs are evaluated on a case-by-case basis. There are no "standard" repairs that apply to a really wide variety of situations.
The overframing that Stilletto mentioned is basically valley framing. Houses that have intersecting roof lines need valley framing. I can give a more specific example if you need one.
Regarding dividing up authorship like you mentioned to blueeyeddevil - I have no problem with that. As long as I get top billing. (-:
I'm not sure just exactly how you'd work the article. Blue definitely spends time planning ahead before he sets trusses, so his input might be valuable.
Regarding erection bracing - Wasn't that in the partial list I sent you? Would some of the stories I related about trusses faling over due to poor bracing be valuable? Or maybe we could find someone who it's happened to and let them tell the story.
I'm sitting here wondering if I have any pictures of a mess of trusses lying on the bowed walls of a house. But I'm not sure offhand.
Bumpersticker: Don't be sexist. Broads hate that.
Regarding dividing up authorship like you mentioned to blueeyeddevil - I have no problem with that. As long as I get top billing.
Seems like I remember seeing "BossHog" in the magazine this month. You're gonna get a swelled head if this keeps up.
jt8
"The difference between greatness and mediocrity is often how an individual views a mistake..."-- Nelson Boswell
"Seems like I remember seeing "BossHog" in the magazine this month. You're gonna get a swelled head if this keeps up."
Probably not - I don't even subscribe to the magazine.
(Insert embarassed smile here)
There's no real need to do housework -- after four years it doesn't get any worse.
IIRC it was the current issue, you might run by your local book store. In the BreakTime section of the mag it seems like I saw BossHog a couple times,but I don't remember what the discussion was.
jt8
"The difference between greatness and mediocrity is often how an individual views a mistake..."-- Nelson Boswell
"...run by your local book store."
I guess you've never BEEN to Carlinville....
(-:
Q: Why can't blondes be cattle ranchers?
A: They can't keep their calves together.
You're right: There were two discussions, Boss Hog was in both.Justin Fink - FHB Editorial
You're just trying to butter me up so I'll write this article, aren't you ???(-:
One nice thing about egotists - they don't talk about other people.
You're right: There were two discussions, Boss Hog was in both.
And from those humble roots, he works his way to making his fortune in publishing! ;)
jt8
"The difference between greatness and mediocrity is often how an individual views a mistake..."-- Nelson Boswell
I like Gene's ideas. But there's much more there than will fit in a magazine article. More like enough for a whole issue, or a series of articles. How about following a big truss job all the way through, something like this:
Article #1: Planning and design. What can an architect do to use trusses more cost effectively? Turning what the architect hands you into a truss design.
Article #2: Making them at the truss plant. Why site building your own trusses can't compete.
Article #3: Setting and Safety. Getting them all the right way around. Simpson hardware and all that.
Article #4: Finishing
What the magazine needs is more depth.
-- J.S.
John, you are certainly right about the depth thing.
We used to get some depth, but the FH scene has been getting shallower and shallower.
Just one example. Go way back and see what they did when Michael Byrne did articles on how to build a tile shower or tub surround. Meaty stuff then, but all we get is fluff now.
I use trusses on roofs with alot of overframing a few things that should be included in your article about trusses is the overframing parts. For the most part the computer programs you truss guys use is smarter than I am.
I've seen more than jobs than I can recall where the valleys are crooked, the ridges are running out of level the hips are all messed up. I've fixed alot of bad ones.
Another thing that needs to be addressed with trusses are the girder trusses, people just put them next to each other with a few nails and say "good enough." Well the plans that came with the trusses has a nailing schedule maybe you should read it.
Hip trusses that step up from the girder to the ridge has got alot of people baffled, I think that if a truss package is sent out, send the "lay down" hip truss with it. It's just a gable truss that you lay flat on the tops of your trusses that provides the framing for sheathing as well as lining up the points for the ridge of the hip.
Floor trusses are another beast, lack of strongbacks, cutting chords for pipes.
BTW on the job I'm framing right now Timberfield Truss Co. came out and measured the foundation before we set any I-joists and the measurements didn't exactly match the blueprints no big deal right? They still build the trusses to the blueprint and now I have a whole 1/3 of a house that I have to move trusses add bearing points to make an inspection possible.
What truss company do you work for Boss? We may be looking for a new supplier.My Mommy says I'm special.
<<I use trusses on roofs with alot of overframing a few things that should be included in your article about trusses is the overframing parts. For the most part the computer programs you truss guys use is smarter than I am.
I've seen more than jobs than I can recall where the valleys are crooked, the ridges are running out of level the hips are all messed up. I've fixed alot of bad ones.>>
...that seems interesting, but I'm not sure what overframing means - can you shed some light on that for me?Justin Fink - FHB Editorial
The term overframing means after you set your trusses, some areas you put the roof sheathing on and stick frame your valleys in over the roof sheathing "California Valley" I've gotten the valley trusses and don't really care for them so I stick frame all of mine.
Hip sets of trusses require purlins on top of the trusses that run from the girder truss to the ridge of the house, some truss companys make lay down hip trusses that resemble a gable truss and all the framing is mostly done by laying that truss in place. The purlins are 2x4's two foot on center and it's a pain to get 16' 2x stock 3 stories in the air on a 12/12 pitch.
This house we are framing right now has about all the overframing I've descibed and then some maybe I'll get some pictures around and show you what I mean.My Mommy says I'm special.
Stilletto, I don't like using "valley trusses" either. Maybe it's just me and I haven't used enough of them, but they seem to be difficult for me. For one thing, I always work alone on a layon. Using valley trusses almost always requires two guys. The onther thing is that if it's a large layon, the trusses can get large. I don't like wrestling large items on a roof.
The purlins on the step downs is another truss that I don't particularly care for. I've done hundreds of these stepped down hip ends and I've done them every way imaginable. When I started they didn't drop the step downs and we had to block every two foot on center. That was a painful thing to do. I eventually came up with the idea to move the step downs off layout and lay the framing over. At some point after that the truss companies mercifully started dropping the stepdowns and I didn't have to be such a pioneer.
I've even pre-framed my fair share "purlins" I thought I was pretty clever doing that too. But, eventually, I settled on the method that I do now....I just pile a bunch of linial in the box and shoot myself upto the hipgirder and go to work. I start in the middle, layout the linial (33.94" oc for a 12/12) and lay up to the peak, climbing and nailing as I go. I then move over 24" and go it again.
The trick to making this job easy is having the plywood layed on the lower hipset first. This gives you somewhere to park your materials and saw. Most guys won't sheet this section till the entire roof is framed because they are unsure of their framing. They have a need to get it all strung from the bottom to the top to ensure the plane of the roof. I've managed to overcome that tendency and it's made the job far easier, even when I didn't use the skytrak.
Take a chance...Columbus did!
blue
This is a great thread, regardless how the article turns out.
Boss is right about not being able to show a truss equation. All trusses are designed by computer for optimization. Simple trusses can be analyzed by hand quite easily, but truss companies would go broke using an concservative design like that. ...that's not a mistake, it's rustic
"Simple trusses can be analyzed by hand quite easily"
Did you read my earlier post on this? Designing trusses by hand is no longer considered "kosher". In a couple of years I'm all but certain it will no longer be allowed AT ALL, not matter how small or simple the truss.
Truss design is now so complex that it would be virtually impossible without computers. You don't do one simple load case wth a pin joint model like you might learn in a college course.
There are 15 to 20 load cases on EACH truss. Bending moments and shear are figured every inch or so along every chord segment. I couldn't even begin to understand the math involved.
"All trusses are designed by computer for optimization......truss companies would go broke using an concservative design like that."
Trusses are designed on computers for speed and accuracy - Not optimization. The way they have us design stuff now is sometimes MORE conservative and sometimes less so. Depends on the complexity of the truss.
Corduroy pillows are making headlines.
I do the hip sets the same way you talked about nailing and walking the tops of the trusses from the center out, if the trusses come with the layon hip I set that with the crane while its there.
I frame all the purlins first though, guess I'm not good enough yet to sheet the mono trusses first and then frame the hip. :)
This house I'm building right now has become a pain in the butt, the truss company knew that the house wasn't getting a brick veneer and still made the trusses for it, the heel heights are all over the place, 7"-9"-13 1/4" and 12". So this house is getting one of the things I try to avoid, unequal overhangs.
My Mommy says I'm special.
I frame all the purlins first though, guess I'm not good enough yet to sheet the mono trusses first and then frame the hip. :)
Don't try to bs a bser! Your good enough.
I was hesitant at first to sheath the lower hip set until I had the entire thing framed until I thought about it long enough. The two points of the lower hip, that govern the upper hip will never change, right? Let's face it: the corner of the fascia is fixed and so it the tip of the hip set. So.....after I sheath the lower section, I pull a line from the corner of the fascia, through the tip of the hipsset and all the way to the peak. I set the tip of the peak in line with the lower two fixed points and that normally planes everything in.
Of course, being the chief boogerer...and chalkline hater, I sometimes use shortcuts. In fact, most of the time, I just sight the tip of the peak in line with the lower two fixed points. Sometimes, if I'm off with my sighting, my hip ends up with a slight curve. I've had to rework a hip or two in my day, but it usually only involves a small ten minute delay. if you stick to the stringline method, you'll never be wrong.
I've also had a few jobs where the truss company build for brick on a siding job. It's usually the fault of a wishy washy builder, not the truss company, but of course we know they aren't infallible. Like you said, the fix is easy....different sized overhangs, which we also strive to eliminate. It's kind of weird...in some localities, they intentionally build differnt overhangs and in my neck of the woods, they avoid that like the aids plague.
blue
Edited 5/6/2006 10:31 am ET by blueeyeddevil
You might be right about the BS, worth a try right? Lately I thought about setting the ridge purlins getting all my points in line then sheet the monos then frame the rest of the purlins.
But you are right about the set points of hip trusses never really thought about it that way and I'll be sheeting the monos first from now on this will give me a working platform.
Unequal overhangs are considered a plague here as well, not sure why the regional differences though.
My Mommy says I'm special.
Edited 5/6/2006 4:41 pm ET by Stilletto
Blue or Stilleto,Could you explain in more detail what you're talking about with these hipsets?We've unofficially determined to not use trusses for hips because of a few jobs that drug on. I'm quite sure that the reason we had so many issues is because we weren't savvy to the tricks of installing hips. Maybe we shouldn't be so quick to throw out the bath water...
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Jon, if you are rejecting trusses solely on the basis of the alleged complications surrounding a hip set, you are indeed throwing out the baby with the water.
We build our hipsets on the ground. Heres a picture of one I've preframed on the tables. I don't normally put the hips and jacks in, but I always put the commons in. We swing this entire mess in with the crane. It really isn't that hard setting it. Once it lands, you can jerk it around till it's perfectly set.
As you notice, the top chord of the main girder is about 20' long. At each end is the "tips" of the girder that I was speaking of. It appears that this roof is a 12/12, so the next truss that is set will be a "stepdown". It's top chord will be 4' shorter since we are setting the trusses at 24" oc.
If you do the math, youll see that we have 4 "stepdowns". The fifth truss away from the girder will have a peak. When we string a line from the tip of the facia, to the peak, it will pass through the tip of the girder.
Also, note that this end of that hipset has a pan ceiling built into it. 90% of the ceiling is done once we set the roof trusses. We'll have to put some blocks in on the inside where the pans meet at their "valley".
This is a very typical hipset for us. As you can see, we lift it from the center....which isn't recommended by the truss institute packages.....Boss is right...we do ignore most of the info LOL! The truss will tilt slightly in favor of the fascia line, but it is very easy to balance once it gets near it's landing place up on the walls. It wouldn't be unthinkable for me to set this alone if I was up there, but we normally have two people recieving it. A third person really doesn't help much and would normally be standing in a dangerous position when it is coming in so we don't bother sending a third up. I rarely use three people to recieve trusses...only if they are unusually large.
blue
Blue,So do you still have to block the step-down trusses? Or do you set those trusses the appropriate distance towards the ridge and install your "lacers" 24" o.c. and sheathe right over them?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Jon, we don't have to put blocking in. The lacers lay over the stepdown trusses and are spaced 24". The sheathing is nailed to the lacers.
It's really a very easy thing to do, once you get over the alleged complications of it. The suggestion to sheet the lower hipsets before tackling the upper framing is key to simplifying the process. Without the sheathing, the framer is forced to dangle in the air and have no base to stage everything. It gets tiresome doing the balancing act and playing monkey boy.
I don't have any pictures showing the sequence of the hipset framing but I'll make sure I take some on the upcoming roofs that well be doing this month.
blue
Jon, work with a good truss designer and fabricator, and your arrangement will look like that shown on the attached pic.
The point of roof plane where ridge meets hips determines the location of the last full-peaked common truss, and the layout for the entire section of the hipped roof trusses. This is no different from framing the roof with sawn lumber, with the last commons reaching up to meet the end of the ridge, then the hips splaying out from there.
From that point, stepdowns proceed out to the two-ply girder on which hang the hip trusses (two ply shown here) and hip jack trusses. With a table like Blue uses, or an arrangement of blocks and beams, it is fast and easy to make up the whole end-set on the ground, then fly it up with the hook.
The laydown or sleeper (my terms) truss is fabricated with its 2x3 chords lining up with the layout of the jack trusses below, for easier sheathing layout and nailing. The trusses this sleeper bear on all have dropped top chords so the sleeper top is in roof plane.
Would there be any reason other than crane capacity not to sheath that section on the ground, too? It sure looks a lot safer and easier.
-- J.S.
John, in most cases, there really isn't a savings in time to sheath it on the ground, or in the air. It takes us x amount of time per sheet, no matter how high it is.
The gain in safety from the reduced possibility of falling, is offset by the increased problems associated with setting the heavier, and less accessable assembly.
With all that said, I have, on occasion pre-sheathed some roof systems on a small scale. Here's a picture where I've presheathed a small section to accept a small layon.
Usually, the amount of time needed to make sure everything is perfectly in unison with the existing wall frame is excessive compared to the time saved. Sometimes I just get carried away. I presheathed on that house, but if I did the same house again, I'd probably not.
A huge reason that we don't feel any need to presheath is because we don't make a habit out of falling off roofs and getting hurt. We also have a Skytrak to shoot all our supplies up, as well as to provide us with a safety net (figuratively speaking).
I have thought of setting entire roof systems on the ground, then tilting the entire structure to create a flatter plane to sheath, but I can't justify the extra set up time.
blue
Jon, heres a pic of a hipset that has been sheathed. In the background, you can see a series of stepdowns on the upper roof that have been set, but haven't been laced. The lacing will run vertically and form the basis for the sheathing framing.
blue
Jon, here's one more pic of a hipsset.
This is a lowpictched hipset that we've preframed out in the mud of a farm field. It also has a pan ceiling that is part of a great room. This shows a more typical preframe technique that we use: we don't install the hip or the jacks till the hipset is set on the walls. It would be very hard to properly align the hip in the mud and threfore risky and time consuming to nail the jacks up, only to find out that the hipset is torsioned/twisted and had to be taken apart.
If the hipset is slightly twisted and we just put the commons on it, it will straighten itself out when it lands on the walls. We might have to release the lacer to pull the tails to where we need them to be, but once it's landed, it doesn't matter...it won't fall over or fall apart.
blue
I almost hate to offer any advice about setting hips, since I've only actually set one myself. But I have walked a lot of guys through it on the phone. I always suggest starting with the hip girder and bracing it with some hip jacks. You gotta put them up and attach them to the girder anyway, so why use braces? They're always the right length...The step-downs almost always follow 2' O.C. from the FIRST ply of the girder. (Ignore 2nd and 3rd plies as far as spacing goes)You need to figure out where your "odd" space is. Only about one hipset in 500 works out to be 2' O.C from one end to the next.There are probably 10 different ways to do corner sets, so I won't even go there. Do you have a truss guy that you trust to help you out and not give you any BS? If so, next time you get a hip you might ask him to walk you through it. Catch him in a good mood and he might even come out while you're setting the trusses.
Bumpersticker: Honk if you do everything you're told
Boss,We do have a good truss guy (Blue Ridge Truss in the Shenandoah mountains near Winchester, VA) so I will definetely consult with him at our next opportunity to do a hip roof.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Here is an example of overframing that I did today. Sorry I forgot about some pictures for you to see.
The main house trusses all hang off the grider truss which is doubled, then my valley takes off from there. Can't you hear the violin playing your song.
That's what I've heard called a "California" dormer -- added on top of the sheathing of the main roof. Do you cut an access hole thru the OSB so the interior of the dormer can be inspected for leaks in the future?
-- J.S.
Yes I do, normally I leave out a 2x2' area of sheathing. I didn't this time because I framed this one in place. Saws and nail guns would have fallen through, maybe myself. Not to mention its a 2 story foyer underneath.
Can't you hear the violin playing your song.
Ah, so there's ceiling rather than attic under the main roof. In a hot climate like ours, the shingles on the dormer would get a whole lot hotter than the rest of the roof. I'd expect them to start looking different in 5-10 years. (But then, I don't know if your job is getting shingles, metal, tile, or maybe it's not even your concern.)
-- J.S.
The main roof is truss so there is attic underneath then the ceiling, I leave enough room for ridge vent on the dormer and that is about all I can do with it.
I don't forsee and shingle problems but who knows, I may be wrong too. It gets hot here Michigan, but not terribly hot. It seems like its winter longer than summer anymore. :)Can't you hear the violin playing your song.
The question I have for you, has to do with your overhang for the flyrafters. Do you find that your method is strong enough without lookouts?
We've started framing our overhangs that way, but on longer runs, I usually cut in a couple of lookouts.
Nice looking work by the way.
The overhangs are very strong. I nail the fly rafter off very well, probably 4" OC and they don't budge at all.
I use 12" on all my overhangs so the ladder is a good fit. If I build over 16" I use lookouts. I just order my gable truss an 1-1/2" shorter than the rest so the lookouts go right over the truss without cutting.
Thanks for the compliment, I really dig your stairs that you posted as well. I have a set right now of 180 degree, six step winders that I am trying to finish. Can't you hear the violin playing your song.
Thanks for the comments.
Reason I asked about that, is that the roof we started today is I-joists for the main span and you can't notch the topflange, even with a gable wall under it. I'd prefer to frame the overhang like you did. It just looks clean. We usually frame for 12" overhangs, but now we'll go about 8 1/2" to the back of the 2x flyrafter. That way, when we side, we can just use a piece of Hardi to finish it off. Wasn't my idea, but I like it :-)
If you really want lookouts cut your birdsmouth deeper on your I-joist, so a 2x will go over the gable, out to the fly rafter, that way you don't have to notch your gable I-joist.
It's kind of like dropping a hip so sheathing will plane through.Can't you hear the violin playing your song.
What can an architect do to use trusses more cost effectively?
Other than to add another year of education (like framing, finish work, case & millwork, & the like)?
Hmm, a subset of that question is "How to get the people relying upon "automatic" roof generation in their drafting software to better meet the needs of the truss designer?"Occupational hazard of my occupation not being around (sorry Bubba)
"How to get the people relying upon "automatic" roof generation in their drafting software to better meet the needs of the truss designer?"
I'm generally less worried about the roof planes, and more worried about how to support the 2nd floors that they have mysteriously floating out in the middle of the floor plans.
Q: How is being at a singles bar different than being at the circus?
A: At the circus, the clowns don't talk.
how to support the 2nd floors that they have mysteriously floating out in the middle of the floor plans.
Oh, now you're just being picky <g>
Next thing, you'll expect the stairwells to line up; or that the DWV lines not hang below the LR ceiling . . . Occupational hazard of my occupation not being around (sorry Bubba)
They might look at it as being a sort of "sales" article
No more so than an article about PEX plumbing.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
I'd head over to your local truss makers and ask them. The guy that delivered the trusses for me had some stories of things he had seen go wrong.
Steve.
Actually, I *AM* the truss guy. The unofficial resident truss geek. I'm looking for feedback and ideas about what has happened to others that would make a good article.
I hate quotations. Tell me what you know. [Ralph Waldo Emerson]
Haven't there been a lot of "can I?" kind of threads here over the years? ie: what kind of field mods are OK, how to properly spec (or salvage an improperly spec'd) truss?
<<what kind of field mods are OK, how to properly spec (or salvage an improperly spec'd) truss?>>
I'm liking this line of thought Paul - this might be somethign to consider Boss.Justin Fink - FHB Editorial
Head over to the newsgroup alt.building.construction and get the email for the guy that thinks the truss makers' software doesn't make them strong enough and is going to design and build them himself. That should make a good start to finish story on what can go wrong!Steve.
On a sidebar show a complete equasion for a simple truss, thatway some do it yerselfers might think twice about building their own. Went to the local truss place yesterday and and asked what grade of lumber they used. 1 and 2 but he said 1400 and 1550 etc. I wasnt familiar with that and he said the boards are bent and a machine reads the deflection and automatically grades them . Price for 24 trusses and 2 gable ends ,30 foot span 6/12 pitch was $2200 delivered on the ground including tax.
"On a sidebar show a complete equasion for a simple truss..."
That would take a whole magazine article, and would be completely beyond my grasp. I can't even BEGIN to explain how trusses are designed beyond
I know in college that teach how trusses USED to be designed as pin joint models. But that method is no longer used by truss manufacturers. I expect the next revision of the NDS will no longer allow it to be used at all.
Not that a DIY building his own trusses will pay attention to the NDS anyway....
Grandchildren grow more quickly than children.
SteveFF made a comment about a discussion oin another BB. I went and found it ... this guy needs help. Here are exerpts:
i am building my own trusses and i have read that its best to splice
the lower cord close to the center, my ? is where do you splice the top
cord. i found the it on one web site but it delt with pressure points
and i did not understand. thanks bill
XXX
Bill:
I am not a "pro", building engineer, PE, ex builder, etc. With all
respect, I think if you have to ask such a question you should not be
building such a critical element as trusses.
It's part of the learning game by actually researching and doing of
things. Part of that process is the Aw ####. An Aw #### with roof system
trusses can be very expensive and even deadly. If the reason you are
choosing to build them is driven mostly to save money, I think this is a
severe mistake. Just my .02.
Good luck, really!
XXX
thanks for the replys, the concern for safty is the reason why i
considered building them myself . after a lot of reseach i found post
from inspectors where trusses had failed because the truss manf. had
relied only on their software to design the trusses to code.lets not
forget code is bare minimum. sorry but i believe most small trus manf.
would be up a creek if you took their software away.i have done a lot
of reseach on truss design, how and why they work,what design works
best for a given span, what type and grade of lumber, snow loads,live
loads,dead loads,the only thing that was not clear was the location of
the top cord splices
XXX
thanks very much to all the replys, but does anyone know the answer to
my original question? thanks bill
XXX
Sure, I know, but I get paid to answer questions like that.
The short answer is, "Put the splice anywhere you want it in order to
optimize the material, but you must design the splice to carry the chord
member forces."
XXX
thanks bob, i do'nt think you have to worry, from what i have seen
there are very,very, few people like me that prefer to do eveything
themsevles, thanks agian bill
XXX
guess you've also learned that you need a hydraulic press to attach the
metal splice plates
XXX
yes i have . I think one might adapt a port-a-power to do the job. i
would welcome your thoughts.thanks bill
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
I've found in general that there isn't much point in talking to anyone about building their own trusses. (Most of the time) They know they're right, and there's no point disagreeing with them. People sometimes get downright hostile when you disagree with them about it. From what you posted, I'd say that guy knows very little about truss design or the truss business. And he's not really open to any help. So please don't point him my way...
Was today really necessary?
Actually, I have seen one great example of a DIY built truss. My father built one in his house when doing an add on. Made it with a bunch of scrap wood from the shipyard.
Of course, this was over 30 years ago....before software. And he WAS an engineer.
Every time i'm in their attic and see it I think "that's pretty cool".
Edited 5/4/2006 12:50 pm ET by Brutag
Boss, I think that type of article would/could make for some interesting reading. I doubt that you could cover everything that could go wrong, but it's worth a try.
Over the years, I experienced every problem with trusses known to man. I've also solved every problem with trusses known to man, LOL!
Trusses are a lot more versatile than any stick framer would know and when a problem occurs, it's rarely any more trouble than a quick call to the engineer for a quick fix.
I'd say the number one problem is something that involves erection bracing. There are many different philosophies and just as many problems. If the erection bracing is well thought out and exectuted in a logical sequence, the trusses will be set smoothly and fast. It doesn't take much though to set an entire roof out of whack and that make the installation of the roof sheathing diifficult and slow.
The number one problem I've had over the years is getting the carpenters to properly anchor their first truss, then run the primary lacer directly from that anchor. It's not unccommon to see competent framers fastening their anchor, then running their lacers from a point that might be two or three feet away from the achor. That might be fine for the first truss, but once you have a couple tons of trusses relying on a poorly executed lacer, things can get dicey.
Gotta run...it's American Idol time.
blue
Erection bracing is a tough subject. Seems like every time I bring it up, guys take it like it's some sort of personal attack - Like I'm saying they don't know how to do their job or something. They just don't want to hear it.But I've sure been involved in some messes. The worst were commercial stuff. But there have been a lot of houses, too. One in particular come to mind. A guy who was just starting out as a GC set trusses on a house. They set and braced the trusses, but didn't get any plywood on. The next morning when he got to the jobsite the trusses had all fallen over. The GC called us the next morning asking us what to do. The first thing we do is go out and take pictures in case there's a lawsuit. Then we start giving the contractor or HO the bad news. For starters - Our insurance doesn't cover this. And no, we won't replace the trusses for free. The next question is: "Can you give me repair drawings for the trusses that are broken?" The answer is "NO". Our engineers won't provide repair drawings for trusses that have fallen, because the lumber may have hidden damage. The trusses have to be replaced.The GC says: "Well, the trusses aren't all that bad. Send a crane over and we'll stand them back up. Again, the answer is "no". We won't re-set the trusses for liability reasons, since our engineers won't back them. By then they're generally pretty hot. Often we get threats of lawsuits, since we didn't warn them about truss bracing problems. But we put bracing info in a packet that we send out with EVERY delivery. And it's listed on the invoice that you signed at the jobsite, so you can't say you didn't get it.In the case I mentioned, the guy called his insurance company. They sent a real jerk of an inspector out who really raked him over the coals. They made him leave the trusses there for a few days while they decided what to do. By the time they agreed to let him move the trusses, the walls were bowed all over the place. The insurance company didn't particularly pay well and the guy got screwed pretty bad. (This was American Family Insurance, and I've never forgotten that) He told me he ended up losing several thousand dollars and was put about 3 weeks behind schedule. That was a real blow for someone just starting out. I really felt bad for the guy..One humorous story comes to mind too. A DIY built a real simple house not far from the plant. They set one gable with the crane and run one brace from the ground up to the peak of the trusses. Then they set the rest of the trusses, running only one single brace along the ridge to the other end of the house. While the crane is folding up to leave, the DIY goes around to where they started and knocks out the ground brace. The trusses all promptly fall over. I didn't really feel bad for this guy...
You can't fix stupid [Ron White, AKA "Tater Salad"]
Looks like you have many good areas to cover. I would like to see something that covers in some depth properly laying out truss locations when you have girder trusses, i.e. multiple trusses supporting hip trusses which change direction. I'm thinking of an article JLC which showed pictures of a hip that had multiple planes in the roof surface due to small offsets in the the location of the girder truss. The picture was taken after the shingles were applied and to an educated/experienced eye it stood out like a sore thumb.
In response to your story about the GC I would think that there is no way those trusses were properly braced or they would not have fallen over with or without the plywood on.
1. In your documentation for the truss package does your package provide an engineered layout and sizes of the member braces for the longer chords/members? If required.
2. Does your documentation provide a layout and sizes for the out of truss-plane bracing required to keep the entire truss package vertical after the ground bracing is removed ? If required.
3. Does your documentation provide a layout and sizes for any strong backs required?
Many users of truss packages assume that those single line of 2x or 1x running straight down the surface of the trusses and parallel to the ridge or eaves is all that is required. And then they assume that the plywood or OSB deck will provide all the bracing required and never add more material.
I do not intend these question as an attack I just don't see many truss packages which give the required info, i.e. location and sizes of braces as well as erection bracing. I think the truss manufacturers are in the best position to provide that info, however many of there specifications say it is the responsibility of the purchaser to determine the required bracing and they provide a generic picture or sketch showing a generic layout of bracing.
Off soapbox for a moment to say I have been very impressed with your comments and many others on this site providing help and education for many newer builders and diy's
Thanks for comments and I look forward to the article.
Jvhannah
JvHannah, I have received a complete truss erection bracing package on every set of trusses since the 1970's. I read it in the 70's and understood the theory and have never had a problem.
You would think that every carpenter would have read this package, but most won't bother even if I hand it to them and tell them to read the entire package.
For the record, a single lacer is often enough to temp brace a set of trusses. Other times, we need five points or more anchored and braced and sometimes we have to put in the permanent lateral bracing, including the required x bracing to keep the erection process safe. It's all a judgment call. That's why I make all the calls when my life is in jeapordy.
blue
hey blue, I read all the sheets that came with my package and looked up more info before hand but unless I was given a poor set of docs I felt like I was winging it. common sense kept me safe. I lateral braced to bottom chords 2 runs, ran diaganal bracing in the webbing every 5 trusses, set the first gable with strong backs (three points) and braced to ground and back to building, ran bracing accross the roof plane until the sheathing went on. I think my common sense was all that got me through. THe documents were vague.
Did you look at this document?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Yeppers Jon! Thats the same sheet I've been given several hundred times! It all makes sense to me. I even understand the Spanish version!
blue
What more is there to do HV?
Everything you've said is written and pictured on the documents I get every job. There really isn't anything more to do.
blue
"In response to your story about the GC I would think that there is no way those trusses were properly braced or they would not have fallen over with or without the plywood on. "
Well, they wouldn't have fallen over WITH the plywood on. But you're correct that they weren't braced well enough.
My point in telling the story was to illustrate how much of a hassle it is when the trusses fall over.
BTW - These kind of incidents are often referred to as a "truss collapse". I refuse to use that term, as it implies that something was wrong with the trusses.
In these cases they fall over - They don't collapse.
"1. In your documentation for the truss package does your package provide an engineered layout and sizes of the member braces for the longer chords/members? If required. "
First - A layout isn't an engineered drawing. It just shows where the trusses go. Some places use the term "placement plan" to describe a layout for that reason.
In our packages we have a drawing of every truss on the job. And if permenant web braces are required they're shown on those drawings.
We don't specify erection bracing, though. But in some parts of the country that's changing.
"2. Does your documentation provide a layout and sizes for the out of truss-plane bracing required to keep the entire truss package vertical after the ground bracing is removed ?"
We just provide the general guidelines for bracing - HIB-91.
"3. Does your documentation provide a layout and sizes for any strong backs required?"
By strongbacks, do you mean on floor trusses? Strongbacks are recommended 8 to 10 feet on center on floor trusses. Since they're not REQUIRED, they're not shown on design drawings or layouts.
"...I just don't see many truss packages which give the required info, i.e. location and sizes of braces as well as erection bracing."
There's a reason for that.
For many decades, individual trusses were considered to be a component of an overall building. Truss manufacturers weren't responsible for the overall design of a complete roof system any more than the lumberyard who sold you lumber was responsible for specifying wall erection bracing.
Over the past few years there has been a shift in the other direction. Some places are now requiring that the truss company provide erection bracing instructions specific to each job.
I don't really have a problem with truss companies furnishing this, as long as we get paid for doing it. But no one wants to pay for it - They think it ought to be free.
I also think it's more or less a waste of time. No one follows the general guidelines in HIB-91 now, so why have an expensive bracing plan drawn up that's going to be ignored?
I've also seen a lot of other stuff that people are trying to shift over to the truss manufacturer. A while back I got a plan with a note on it that said: "Truss manufacturer to verify that the walls are capable of supporting the trusses". Just this week I got one that said: "Truss manufacturer to verify foundation design". You can't tell me that both of those notes aren't total B.S.
"I have been very impressed with your comments and many others on this site providing help and education for many newer builders and diy's"
I appreciate the kind words. I've certainly learned a great deal more here than I could imagine that I've taught anyone else.
Bumpersticker: Do unto others before they do unto you.
Boss - Good luck with the article. My stuff so far has been stick built, so anything I read will be an education.
On the subject of "collapses", I represented an archi a few years ago where the roof went over and it was a mess. One guy got hurt IIRC. The GC stood the trusses, then while the crane was there he put two flats of plywood up there to save the carrying. Didn't bother to properly brace them first.
FWIW, I don't believe that it's the truss co's responsibility to do a bracing plan. There are too many variables on every site. An erection schedule makes more sense.
Don K.
EJG Homes Renovations - New Construction - Rentals
Boss,
The truss use 101 and working with the factory may make excellent side bars without getting to sales-pitchy....that's not a mistake, it's rustic
"...The GC stood the trusses, then while the crane was there he put two flats of plywood up there to save the carrying. Didn't bother to properly brace them first."
No amount of bracing will make roof trusses carry a pile of plywood. The literature we sent out specifically warns against doing that.
The worst incident like that one that I have been involved in was on a church gym. The framer set the 75' trusses and braced them very poorly. While the crane was still there he started setting plywood on the trusses.
The trusses buckled and went down with 9 guys on them. Some of them were seriously hurt.
Turns out the framer had no insurance of any kind, was from out of state, and didn't own anything but a pickup truck. The church ended up taking a BIG financial hit.
Women would rather be right than reasonable. [Ogden Nash]
Hmm, it occurs that a "sidebar" on unusual situations might be apt, covering things "some" might think obviate trusses as a solution, 'dutch' gables & gambrels come to my mind. Mulitple and spilt-pitch roof design might be another.
I checked last night, and the house south of town in the tonier (not a subdivision) new construction has its roof dried in already. This was one I wanted photos of in a bad way. The floor plan resembles a couple-three 'french sevens' for want of a better description. Who ever they shopped the trusses to just cut the Gordian knot on the design.
All the trusses were laid out perpendicular to the long dimension ofthe plan, and then noulded to fit what ever the roof profile underneath was. Ok, not that big a stretch with some the desing software out there, but boy, did the delivered product look funny. (Seeing a truss with two peaks and a couple of valleies is worth a double-take--seeing it set across the plan at an angle, but parallel to all the other trusses was more than a bit unique.) 'Course, they're gonna need B.E.D. to come frame the soffits I think <g> . . . Occupational hazard of my occupation not being around (sorry Bubba)
> BTW - These kind of incidents are often referred to as a "truss collapse". I refuse to use that term, as it implies that something was wrong with the trusses.
> In these cases they fall over - They don't collapse.
"Domino" seems to me the best word for this -- brief and clear.
-- J.S.
I think the option should be given but not mandated for a detailed job specific bracing instructions. It would help those who want to know. Anyone who values information and knowledge would pay for it. A lot cheaper than mistakes in the long run. Maybe I'm a minority in this catagory but we are still out there. we just figure everyone is going to pass the buck so we struggle to find the info here and there.
"I think the option should be given but not mandated for a detailed job specific bracing instructions."
Interesting idea. But I doubt there would be many takers.
Last time I had a specific bracing plan drawn up it cost about $3,000. The vast majority of contractors won't pay for that.
The cost will likely go down if they eventually come up with software to draw the erection bracing plans. But for now they're all done by hand by engineers. And that's obviously expensive.
Socialism - the equal distribution of poverty.
Hv, you are given all the informatiobn regarding permanent bracing. If the compression chords need something, they'll show it. If they don't, you don't need anything. All the temp bracing that you did while setting the trusses can be removed and the trusses will stand.
You seem to be seeking something that isn't required. That would be like complaining about not getting a detail sheet for temp and permanent bracing of the the walls as you build them. At some point, you have to accept that if your not qualifed to build and stand walls, you shouldn't be doing them without someone more experienced. That same thought applies to the trusses. The erection bracing information is written for professionals, by professionals and since we are skilled, it all makes sense. If I was reading some information sheets written by a drug company to a doctor, I probably wouldn't understand it either.
Maybe your information packages are different. Mine ar put out by the national associations for trusses.
blue
Blue, Appreciate your honesty but I belive I stated initially that this was my first truss erection. I also did not get the sheets Boss stated and what I did get came the day of the delivery wich was just before I was installing them. To respond to your comment, I am not a framer, I can do basic framing but I am not a framer. I am however a professional in the sense that I care about the final product and see it as my responsibility to know what I need to know to do things right. Even if it means I admit I don't know everything. I do a lot of things in all phases of the job but since I am not an expert in all should I pack it in? How else does one become a professional if not through experience , education, asking questions? I'm guessing you were there once.
You're completely correct, that for first time truss installers there is more to know than meets the eye and too often the documentation from the truss supplier doesn't go far enough.
I have yet to see a set of trusses that have a decent diagnal bracing plan that would make sense to a truss novices. Instead a vague reference is made to follow the truss manufacturers assocation guidelines on bracing and installation, with no clues as to have to actually set eyes upon such a document. Very few general purpose carpenters or smaller general contractors even know what I'm talking about, yet many trusses are sold to these occational users.
Ask a crain opperator how many crews installing trusses know what's going on. It's not the truss mfg. problem, but it is a widespread problem nontheless.
thanks for the support trout
I find it interesting that with the number of total truss colapses during construction that carpenters don't put more thought into it. It sounds like you are simply insisting on understanding something new before taking the risk of replacing a set of trusses on your dime.
No carpenter who has lost a set of trusses has ever gone into it thinking that will happen. I'll take a little education over a lot of trial and error every time.
:-)
HV, I went back and read each post of your regarding the alleged lack of information and my guess is this: you are overly obsessed with the need to get more specific information, and because you can't get it, you are somewhat paralyzed because you can't analyze.
I often suffered from that same syndrome in my early years of Carpentry. After gaining many years of experience, I'm a lot less needy when it comes to that type of specific information. Right or wrong, that's how our industry is. We don't need every step of our way engineered and written down on paper.
I'll say it again: the generic version of the erection bracing shows everything you need to know about how to temp brace a set of trusses during erection. If you are paranoid, you could employ that system of bracing on every chord on the truss, and layer the top chord with bracing every 2' oc. More experienced guys like me will put the minimum amount of bracing on, which will ensure our safety and allow us to make money. Our experience guides us. Since you don't have that experience, you seem to be clamoring for the engineers at the factory to guide you and include a written and specific set of temp bracing plans. A comprehensive set of plans like that might be necessary if you were setting 80' trusses, but I doubt that beginners are setting trusses like that. So, if you are setting 28' trusses, just read the information that comes with the trusses and use your common sense.
By the way, my brother is a mechanical engineer and he couldn't erect a set of 28' trusses because he would complicate the hell out of everything and justify the need for written instructions too.
A little experience goes a long way when setting trusses. That's why guys that flunked out of high school can do it without written specs.
blue
Hey Blue, Your assessment of me is pretty good. I do need to have all the facts before I feel good about moving foward. I even feel paralized from time to time. I'm getting better these days with just going with things but you must admit that an article geared towards both novices and experienced guys might put some minds like mine to rest. This thread was asked for our input on what We as the readers might want to see in the article and what We as contractors have experienced with trusses. Just trying to be helpfull for others who are like myself perhaps. I saw some of you pics - you are definitely in a different leage than I but we both make our living in this trade and I see nothing wrong with offering up support, experience related advice, etc. I love teaching someone new what I know just as much as I like learning something new. If we want more new comers to the trade, It's our job to teach them , not make them feel like they shouldn't be there.
I second the motion for more bracing info with the truss package.
"I second the motion for more bracing info with the truss package."
Why?
Not trying to be a smart-a$$, but what the heck do you want? The HIB-91 sheets are already ridiculously complex and restrictive. And they're almost universally ignored.
What more do you want?
It's hard to be a leader these days - You don't know if people are following you or chasing you.
I didn't get the hib19 sheets and the sheets I did get came the day I was setting the trusses so I had very little time to review them. Maybe I just had a unorganized supplier.
"I didn't get the hib19 sheets and the sheets I did get came the day I was setting the trusses so I had very little time to review them. Maybe I just had a unorganized supplier."
That's typically what happens - The bracing sheets are delivered with the trusses. Since most guys just throw them away, why bother sending them earlier?
This also allows the literature to be listed on the shipping ticket that the customer signs. That proves that the customer got the bracing info, so it helps protect the manufacturer from liability.
If anyone would ask for a bracing sheet ahead of time, I would be happy to give them one. But in the 20 years I've been doing this no ever has.
If you disarm someone you become morally responsible for their safety. [Michael D. Bartman]
Boss -
<<Erection bracing is a tough subject. Seems like every time I bring it up, guys take it like it's some sort of personal attack - Like I'm saying they don't know how to do their job or something. They just don't want to hear it.>>
Why didn't you say so? Add this topic to the list please. If it's something that builders get their feathers in a ruffle about, it's somethign we want to discuss and put an end to.Justin Fink - FHB Editorial
what's a lacer? Diag. bracing? bottom chord bracing?
Boss - it might be worth it to consider dividing up the authorship of this article as well. Would it be helpful to team you up with a framer who installs trusses regularly so that you are freed up to discuss the planning and designing aspects while the framer talks about installation problems? Perhaps BlueEyed is a possibility, just a thought...Justin Fink - FHB Editorial
Erection bracing would be the most common error I've ever seen.
Followed by either not getting the walls straight prior to setting the trusses or setting the trusses crooked (including spinning them end for end).
Good point about improper nailing of girder trusses and not preparing for tuss uplift.
Terry
"...setting the trusses crooked (including spinning them end for end)."
I see that once in a while, but not too often. A lot of truss companies (Most of them?) paint one end of the truss tails so they can all be set the same direction. Since we set the majority of the trusses we sell, our crane drivers pay attention to this.
"Good point about improper nailing of girder trusses..."
Any good engineer will tell you that nailing girder trusses together is of major importance. But I never was a good engineer. (-:
I haven't yet seen any problems that I could say were caused by inadequate girder nailing. I figure this is due mainly to the fact that most girders never see their full design loads.
But it may be a problem in areas where snow loads are a concern.
Q: How can you tell if you are a dyslexic schizophrenic?
A: You always think you are following somebody.
what do you mean by girder nailing? Is it where the trusses are nailed to the top plates?
"what do you mean by girder nailing?"
When multi-ply girder trusses are nailed together.
Kinda like this:
View Image
Motivation is like nutrition. It must be taken daily and in healthy doses to keep it going. [Norman Vincent Peale]
OK Boss,
I was doing an addition on my electrician's house and naturally during the design phase he kept making this thing bigger and bigger. It got so big that trusses were the only option. Big ones. 42 foot span 4 on 12, 25 trusses with a 1 foot overhang. My engineer said to have the truss company engineer that part. So I had the guy come out and mesure for them once I framed the deck. To make things more complicated, I had to cut the old trusses out ove part of the house that the family was still living in tha same day I was setting the new trusses. In order to maintain the interior envelope so not to open up there living space to the great outdoors I temp supported the bottom cord and left the drywall ceiling in tact. I then cut away the rest of the trusses with a chainsaw and set the new trusses 4" higher than the old ones so they could span over the old ceiling. I was then going to turn the old ceiling into a "drop" type ceiling by hanging it from the new bottom cords. Now I had never done trusses before and was scared out of my mind knowing these were the parameters. SO ....... here sarts the long list of errors. I ordered the trusses and assumed all was well since the rep came and measured himself. Well... he put the wrong job name on them and the paper work sat for two weeks before I was asked to approve it. Now I'm two weeks behind schedule. Next mistake, I asked for storage rating on the bottom cord since the attic was to be used for storage and an air handler. My engineer looked at the specs and said no way was it enough to carry load. The truss comopany engineer said it was. Who was I to believe? I chose to trust the truss guy. Still don't know who was wrong or right. Third issue, I spaced two trusses for a pull down stair. Then later the owner wants it somwhere else. had to engineer a modification. not a big deal but time and money. wish I had spent more time on that detail. Fourth issue, the roof overhangs didn't tie in well at one foot so
Boss,
I have to agree with a lot of the guys posting. I'd like to see less on mistakes and more on benefits, what trusses can do, and how to set them right and quickly when they are complex.
As a side note, it seems like FHB is much less technical than it used to be, so please don't let the mag "dumb" it down for DIY or the like. A good in depth truss article by someone who knows would be great.
I'd like to see some details on complex roofs. I'm currently doing a house where the garage is offset on a 70 degree angle to the house. It's a 42' span 6/12 with a 12/12 bastard hip roof. It also has a gazebo style roof over the porch and I would like to see how something like this could be done with trusses.
Maybe the article should be about trusses for complex roofs and how modern technology can create truss packages that weren't available 10 years ago. I've always assumed that there was no way to truss the roofs I stick frame, but maybe the article can show me new techniques.John
Some of the worse truss problems I have had could have been avoided had I reviewed the truss drawings more carefully ahead of time. The few truss suppliers I deal with supply shop drawings - the truss design package - prior to the trusses actually being built. Serious errors are often rooted in these drawings; building widths wrong, room widths wrong that have special ceilings, etc. Really, this all goes back to the truss designer, but the builder (or builder representative) is the second set of eyes that can catch some serious mistakes before they happen. This all occurs before the carpenter is ever involved so, he may not be even aware of this type of thing. Not that it is really the builder's job to get the truss design right, but if he knows what's good for him, it sure saves some colossal headaches and botched build schedules. The phone call with "Hey Joe, the building width in that back section is 34'8" not 33'8" is something that can easily be forgotten and never seen as a big problem resolved, but as we all know, you better believe it is.
As far as field generated problems, I'd say at least some problems are often rooted in just plain not reading the directions... which can be a bit cryptic, since they are "shop drawings" that double as field installation drawings.
"Some of the worse truss problems I have had could have been avoided had I reviewed the truss drawings more carefully ahead of time. "
Actually that's one of the things I had in my outline for the article.
Reviewing shop drawings and layouts not only catches mistakes, but misunderstandings. As you well know, blueprints don't always spell everything out perfectly. Different people interpret things in different ways.
It also catches changes that haven't filtered down the line. I often get questions like: "Wasn't there supposed to be a gable roof on the sun porch? I thought we called and told you to change that."
Sometimes blueprints are updated, and we don't get the most recent version.
Sometimes a framer or GC just doesn't like the way we run ther trusses on complex stuff, and wants something done differently.
So there are lots of reasons to ask for drawings ahead of time and ask questions. I wish more guys would do it.
Don't sleep with a drip. Call a plumber.
<<Reviewing shop drawings and layouts not only catches mistakes, but misunderstandings.>>
I like where you're going with this thought Boss - I would keep this one on the outline.Justin Fink - FHB Editorial
"Top Ten Truss Travesties".
Contact Mr. T He has a story about one of the top five.
Doo Dah, Doo Dah.
Perhaps the rocky mountain states are a bit behind the curve, but problems with trusses are far from "rare" around these parts, at least amoung the better construction outfits. God only knows what the half-ars guys have to put up with. Keeping in mind that the trusses don't function in a vacuum and that all stakeholders involved need to be accounted for. In other words it's probly most instructive to look at truss problems from the broader contractor's view, rather than the truss mfg's.
At least every other year we see trusses that fall over from not being properly braced. It's scarry to think of how many sets we don't see. In windy Wyoming it's pretty easy to lose it all when a weather front passes with 70 mph winds. During the worst weather we've had 2x4s blow across the ground--it would be suicide to have trusses up and not sheathed, or at least very well braced, in those conditions.
With the last 10 sets I've been involved with few have been problem free.
One set of 40' trusses were too long and tall to make a corner on a steep mountain road to the house. Clearly this is something the contractor should have accounted for. As it turns out it was also something the truss mfg should have taken more seriously. They assured the GC that their smaller trucks could make any corner than a 1-ton dually would. Cutting trees wasn't an option, so it was either hire a helicopter to sling them the last 1/2 mile or walk them individually through the woods.
The next set built by company B was dumped at a bad angle with the truss ridges digging in and pivoting an end of the bundle hard into the side of the building. Further, the crane unexpectantly wasn't available so our schedule was set back a few days with the extra time and man power needed to set them the old fashioned way.
Another set cost the company nearly a grand in manpowers when truss strap ancors were set in an ICF wall incorrectly. Quite a bit harder to fix than when working with wood top plates. I've had constant problems with carpenters not realizing how important it is to get the truss layout correct, and imagine that the crews I've worked on aren't that much different than most.
Another set from company C were missing a critical 2x verticle leg over a weight bearing wall. Of course they were red faced and quickly came up with a field fix, but it was a major ommission. Another set from either company D or B, moved cross braces from where they were on the truss plan, and jacked up the hvac ducts.
A set of scissor trusses from company D had a gable end truss built for a standard 8' wall. Even though the engineer at the truss company signed off on it, that's what was built at the protests of the carpenters. The city gave us the option of sheathing both sides of the gable end to stabilize it, or tear it out and build a ballon framed wall like it should have been in the first place.
Another set from company E had a series of hips and gables that had many parts of the roofline 1-1/2" higher than the original blueprints called for. Not a big deal unless you are the guy who gets to make the two line up. That same set had a 2x with a complete stress fracture--a barely visable line across the grain where it was probably on the recieving end of being in a pile of wood mashed by a forklift. The truss guy didn't think that's what it was so I simply smacked it with a hammer and it easily broke in half. "Oh, I guess you were right."
Company E sent us a head scratcher with a smallish dutch hip that showed up in a configuration that I could't figure out and lacked any documentation. After calling the truss designer it seems the original designer was out sick, but another guy would take care of our project. He called back that afternoon and said he couldn't find the documentation, and was having problems figuring out the configuration. He put together a new truss schedule that had a girder truss turned 90 degrees from what the original guy had in mind, but it fit with a little trimming. There were 6 pieces that were a mystery to us all and were chopped up for blocking.
The next set from company D were probably the best, most uniform and finely made trusses I'll ever put up. Apparently the sun and moon were in the right place, the lumber delivery was just right, the trees has moss on the perfect places before being cut and the best truss maker was practicing for a national compitition. Unfortunately, the architect's specs had one end of a girder truss resting on a large solid wood header. The girder truss was also the junction between a vaulted ceiling and flat wall. We knew the thick wood header would shrink at least 1/4" and something would give as the girder truss settled closer to the wall directly below. Sure enough. Some bridges were burned over the conversations that resulted in who was going to pick up the warantee repair.
Then there was the client that wanted a slight change made to the roofline above a window. No, it wasn't the GC's fault, or that of the truss guy, but it was a problem and it fell into the carpenter's lap to fix.
The next set that would have been from company E, were so full of blue sky that the carpenters told the GC to stick it. It seems that truss designers are so quick to make everything a truss, that when small tie-in situations come up that really should be stick built, they will do everything possible to come up with a convoluted solution that is doomed to fail (by their own admission). They were guessing at the exact height and centerline of a second story tie-in roofline that that had to be built within inches to be useful. Wishfull thinking on an old building that is that much out of level and plumb.
Then there was the call from a guy who's son-inlaw was helping make more room in the attic for storage by cutting out some portions of the trusses and laying down plywood. His plan was working well until the ceiling underneith started to sag. Although this is an obvious case of an idiot, each year I hear or see carpenters try to modify trusses because they just don't know any better.
Every situation has a solution, but it all slows down the process and costs money.
At least from the carpenter's view there are enough truss problems, caused by enough different people, to go around. Carpenters definitely need to know more about trusses and it sounds like you'll have a good article or two out of it all.
Cheers