My father wants a garage built and has some reasonable carpentry skills. Although I’m busier than I want to be with my own house and business, I have agreed to help. The garage is small, only 16×20, and is for mainly storage and maybe his lawn tractor. I told him that maybe we should look into site-built trusses rather than ordering them, as I think it would be cheaper to simply buy the lumber and use plywood gussets, PL and 8d ringshanks or staples to slam them all together.
Now, before someone goes off on me, I already have a piss-poor example of a factory-made truss on my backyard shed, which also spans 16′. I KNOW I can do better, specifically in terms of material quality. I also am an engineer, so I can handle the design.
Having said all that – is there any good reason why we should NOT build 11 trusses right on the site, instead of having the local hack lumberyard drop a pile of trash trusses in the driveway? I seem to recall paying $40-something per truss for my shed, and I can’t imagine paying more than half that for materials to build them ourselves.
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There was a thread about Building Your Own Trusses a long time ago. In that thread I pretty much laid out what I think about the subject.
I don't have time to get into a huge debate on the subject yet again.
Good luck with the fallout over your post. This has been discussed before, and several people have very strong opinions about it.
Having said that, I built a garage 25 year ago, and was very short on funds. My grandfather was a structural engineer, and he gave me a truss design. We lapped the joints rather than using gusset plates. The span was about 22 feet. That roof looks as straight today as when it was first built.
Good luck with your project.
A friend of mine used to be a supervisor for one of the Habitat for Humanity-type organizations down in TN or KY. He told me that on many of the jobs, they'd have a lot of volunteers hanging around in the early part of a project looking for things to do. He'd lay out a pattern on the ground for the trusses, and when there were people with nothing to do, he'd have them building trusses. By the time the project was ready for them, they were usually all built. The moral is that if labor is cheap and the truss design is strong and simple, it's quite feasible to build trusses on the jobsite.
Don
Thanks, Boss Hog, for the thread on BYOT.
You should see the junk lumber that the truss plant used to build my shed trusses (and BTW, I did NOT tell them it was a shed prior to ordering). It's clearly stamped SPF KD, and it's got more knots in it than I would accept for regular framing lumber. They are all held together with metal plates, no nails at all. I KNOW I can make better trusses than these - i.e. I'm not willing to put up with that kind of (lack of) quality. I hope the stuff that they build house trusses out of is better - I'd reject every one if it was a house I was building and they all came in like that.
Getting poor quality trusses once is not indicitave of the truss industry overall. Also - There's a lot more to building trusses than just using lumber that looks nice. Connections are everything in a truss. Honestly - Even being a truss guy - I would probably stick frame a building that's only 16' wide.
I bet Einstein turned himself all sorts of colors before he invented the light bulb. [Dan Castellaneta]
"Getting poor quality trusses once is not indicative of the truss industry overall. "
You're absolutely right, but it IS indicative of the manufacturer that my local lumberyard gets theirs from.
Jon,Can you give me one good reason why would you want to build your own trusses for a 16' span roof when you could have it stick framed 10 times faster.I have nothing against trusses but for a 16' span makes no sense at all. I've built 24' garages with no trusses and no center girders plenty of times. Leave the truss building to the truss companies.Joe Carola
They are all held together with metal plates, no nails at all
Which was my first mental question here--what value are you going to use for your connections & gussets? Will that value require a known nailing pattern? (Think about overlapping nails shot in from either side.)
You are an engineer, carry the design process, through. Are the gussets going to have to be in tension or compression, or both? What area are you going to need to mechanically fasten member in tension to members in compression.
Those "flimsy" nail plates actually answer a whole pile of those questions in one go. They have a constant depth, and constant strength over the entire plate, and since they use a machine to set them, the impact tends to be entirely uniform across not only the whole plate, but every plate.
It wil likely sound like I'm nitpicking, and I am, just a bit--but I've had to try and explain why you can't just whack some 4x6 together with sinkers and tip it up as a "decorative" truss. (Those pesky diagonals have precious little area to fasten to at their pointy little ends.)
I've been through some hard-learned lessons on this topic, and I see little need for you to fall down the same bumpy road I've been down (and lost a shirt or two along) a time or two before.
BH will chime in, not all trusses are made of junk--some are just prettier than others. But, the truss company has spent some bucks on desing & engineering, which can be reassuring with 2-3' snow on a roof.Occupational hazard of my occupation not being around (sorry Bubba)
I've built trusses on site several times. First of all the drawings have to be approved.Plywood gussets work fine instead of steel plates punched in.Trusses are not that complicated to build. Make it easy on yourself by setting three sawhorses ,or more on a fairly level site. Reject any lumber that has excessive crown ( more than 1/2" ). Cut each part exactly the same using a template or pattern rafter. Use 3/4" osb or plywood for the gussets. 1/2" is strong enough but some inspectors will turn it down and make you add another gusset on the other side.I nail 8d nails and subfloor adhesive on the gussets.
Temperarily nail or screw the first truss to the horses. Build each truss on top , I usually build about four and then remove them. Depends on how tall you are and the height of the sawhorses.You'll be done building in less than two days. Frame the gable walls on the last two, right on the horses. Sometimes I sheath them too, if they are large I sheath after the end trusses are up.
mike
Just to clear up a previously made, jokingly intended, but poorly executed moment of attempted wit by me in another thread, do not use drywall screws to build your trusses. Do not use Piffin screws either since they are the same thing re-branded.
Everybody knows that. And everyone knows that yer spose to use contak sement!
And staples.
Jon,
I'm with The Boss on his suggestion of stick framing. Any reason why you don't want to? Certainly easier to get the lumber in place And probably quicker too.
WSJ
Re: "I already have a piss-poor example of a factory-made truss"
Poor in what way. As any good engineer knows design isn't often a matter of building the best. It is a matter of meeting a requirement. Preferably as cheaply as possible.
Your talking about a shed here not the space shuttle. A span of 16' is no great challenge. A simple rafter set and joist in 2by4s will essentially cover the gap. Wouldn't take anything more than a "piss-poor' design in a truss to do the job. You could build a better truss. But why? When a simple 'piss-poor' design meets the need. For a hell of a lot less money and trouble.
A lot of this depends on the cost of your time. Get on the phone, read off a set of requirements and a couple of weeks later you have trusses. Likely at about the cost as the materials you would use. These units come guaranteed to meet the requirements. Most come with an engineers stamp.
$40 per truss? Build a truss or two and come back and tell us all about how $40 isn't worth it. As an engineer how much do you make? Exactly how much engineering would $40 get me? Trusses are used because they are cost efficient.
Of course if you just want some way to spend your time and get your hands dirty, a hobby, build trusses all you want. Just don't make believe your doing it for economics or to get a truss that is 'better' in any meaningful way.
at my company we have many PE engineers, well one wanted me to help him build his house, a 200k 5000 sq foot house. So I went to help. His design was to sink 6x6 in the gound at the corners like a pole barn. a 2x10 all around as a header. no header on door or windows. and the concrete was poured directly on the grass with no footers. county inspector turn him down. He pulled out his PE stamp and kept going.So when ever an engineer want to build, I run. Those who can do, those who cant teach. An engineer will not listen to anybody.As far as site build to factory. Its a hell alot cheaper to buy from the factory than build yourself.
Why not build rafters, ridge, and ceiling joists?
Over size the ceiling joists. Put a pop out door on the gable end after you build the roof frame. Strap the tops of the rafter pairs and skip collar ties. Put some ply down on the ceiling joists. You'll have another huge storage area.
I built a little 12' wide garage 8 years ago at my old place just as I described. I used 2x4 rafters 16"oc and 1x4 skip sheathing on that with ag grade steel roof on top. It's never leaked and it's had four feet of wet snow on it several times.
"A liberal is a man too broadminded to take his own side in a quarrel." Robert Frost
best reason I can think of is that you can stick frame it faster than building trusses on site and then setting them.
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