Is this legit for structural end bearing of ridge beams?
Take a look at the pic below. The chimney core, of 4″ block, with 8×12 clay tile flue liners inside has been used to support the main ridge beams. We’ve no other way to support the inside ends.
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Replies
I would have to assume that it would likely be OK. I know it seems inadequate but I've set 27' steels beams that were 17" tall on block with only about a foot of bearing on either end over 8" block, then supprting another 5' height of block wall and rogg purlins. Approved by the engineer and architect and city.... and still standing after 3 years.
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Structurally, it's probably OK. But, there should be a 1" min clearance from a masonry chimney to any framing.
Andrew Douglas: What have you been up to? Jim White: Killin' time... It just won't die.
http://grantlogan.net/
Gene:
I have to 2nd SeeYou's reply. Around here I believe you are required to maintain an air gap between the chimney and any framing.
BILL
I'm pretty sure that wouldn't pass plan check here in earthquake country - one concrete block column supporting the whole roof!
Anyone else notice that one side of that block chimney is supporting loads from three ridge beams?
BruceT
"We've no other way to support the inside ends. '
Uhh ....
frame around it?
and I agree with seeU ... there's gotta be an airspace clearance ....
should be a simple job for any PE to handle.
either box it in with framing or simply move the chimney.
Jeff
Buck Construction
Artistry In Carpentry
Pittsburgh Pa
"Is this legit for structural end bearing of ridge beams?"
Yes, that's done all the time. They have to make it wide enough and add a 4" shelf like a brick shelf on the outside of a house for the ends of the beams to sit on that will butt up to your 4" block. The last one I did like that that was three years ago.
That's what I thought, Joe. "Done all the time," is what I wanted to hear. Thanks.
"Done all the time" doesn't make it right.
Nor that there are plenty of buildings standing for decades that way.
No chimney fire, no big deal. (At least for long time before the ignition point of the wood is lowered enough through periodic heating.)
Or, get a chimney fire going and all bets are off.
Ask your local fire marshall.
"Done all the time" doesn't make it right."rjw2,That makes no sense what you just said, at all.It doesn't make it wrong either. So what makes you think that we would build it wrong and cause a fire? Is this because you've never done it before?Is it right because when there's a fireplace and it's designed right and there is enough clearance. There's 4" of block and then another 4" of block or fire block. From what I remember there was 8" for a fireplace. Whatever it is ,it's designed for this.Joe Carola
Edited 7/19/2006 7:56 am ET by Framer
You sound like the elctricians who say "Hey, no problem with thermal insulation over knob and tube wiring; we see it all the time."
Don't ask the electricians. Ask the fire marshall.
Ask the fire marshall (or the fire disaster recovery crew) about fireS started after decades of insufficient clearance of combustibles and the resulting lowered ignition point of the wood through the decades of pyrolysis(? - miught not be the right word.)
Will every house burn because of the improper detail?
Of course not.
But some do
How many house fires (or what percentage) will it take for you to agree that the practice should be changed?
"You sound like the elctricians who say "Hey, no problem with thermal insulation over knob and tube wiring; we see it all the time."You sound like one of those guys who have no idea what your talking about and when you see something foreign to you, you don't want to no nothing about trying to make it right.What's your problem?I'm talking about doing the job right with sufficient clearance.
The way we frame these are done right.There drawn by Architects and Engineers and approved by everyone. There's enough bearing for the beams and enough clearance for any fires. So what's your point? ""How many house fires (or what percentage) will it take for you to agree that the practice should be changed?""I wont agree that this practice should be changed when you do it the right way because we are doing them the RIGHT way! It sounds like you don't know what way is right and don't think that there is a right way to do it.Your comment about me saying that "we do it all the time" doesn't mean that it's right makes no sense because I'm doing it right. So, how do you even have an argument with me on this?I'm not talking about the idiots that are doing it wrong because I' not.Joe CarolaEdited 7/19/2006 7:04 pm ET by Framer
Edited 7/19/2006 7:09 pm ET by Framer
QUOTE
"You sound like the elctricians who say "Hey, no problem with thermal insulation over knob and tube wiring; we see it all the time."
You sound like one of those guys who have no idea what your talking about and when you see something foreign to you, you don't want to no nothing about trying to make it right.
What's your problem?
I'm talking about doing the job right with sufficient clearance.ENDQUOTE
I was responding to "No problem, that's the way we've always done it" rationale you presented.
Yes it can be done right and it can be done wrong.
Present a analysis of the initial details presented and show why it's OK (it wouldn't be in my area) and fine.
Justifying something on the grounds we've always done it that way doesn't convince me.
"That's what I thought, Joe. "Done all the time," is what I wanted to hear. Thanks."Gene,This is like anything else regardless of what rjw says as if I would suggest something that I've never done before or would burn a house down. It can be done and it is done. It just has to be designed that way from and Architect or Engineer as you know. From what I remember we had 8" of clearance and it met all codes and fire codes.Joe Carola
no gene... it's "done all the time " where joe does business..
in the rest of the world you should cover your bases by running it past code check..
my bet ( yes, i'll bet you some Outback Bucks ) is the code official will either reject it or insist you get a PE to design it both for structural and fire code
you are starting the design process with a huge "black box" ... ( how to support the beams and build a chimney..
you need to make that black box transparent.. and asking how it was done in the past in other jurisdictions is not the solution
i can show you hundreds of cases where it was done exactly that way.. but that was then and this is now
CYA
you don't have errors & omissions insurance , do you ?
Mike Smith Rhode Island : Design / Build / Repair / Restore
Edited 7/19/2006 10:05 pm ET by MikeSmith
I think I have it, Mike. See the pics.
In pic 1, the main ridge has its interior bearings picked up by short posts that go down onto spreader beams, sending the loads down through the walls to below. The longer of the two ridges has an intermediate post and beam support, in addition to its adjacent-the-chimney one. I didn't chop windows and doors into the walls yet, as it doesn't matter when I'm just foolin' like this.
View Image
I gut-feeled all member sizes. If I ever build this booger I'll analyze it all and size them then. A couple we know are considering this little house for a knockout hilltop site over toward Lake Champlain.
All structural elements clear the chimney by at least one inch, as shown in pics 2 and 3.
View Image
View Image
Code check? Whazzat? Our guy here is kinda clueless.
Edited 7/19/2006 10:38 pm ET by Gene_Davis
Edited 7/19/2006 10:38 pm ET by Gene_Davis
Edited 7/19/2006 10:39 pm ET by Gene_Davis
this may be a stupid question . . . but i'm not above asking stupid questionsWhy not shift the chimney over to avoid the ridge beam and the problem? It only looks like maybe 6" or so, including the 1" air gap. btw: great SketchUp drawings. I'm wrapping up some old business and will be starting up on it myself shortly. Impressive.
There is hardly any room in this little house, and fractions of inches matter. I don't believe it can be shifted.
If you go back to the post I made here where I show the link to the plans for the house, and take the time to study plans for the main and upper floors, you'll see.
See what you mean. Was going by the 3d drawings . . .
Forget the masonry f/p and use a prefab unit. Just a suggestion.
Andrew Douglas: What have you been up to? Jim White: Killin' time... It just won't die.
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hey Gene, can you refresh my memory as to how you attach files to show up in the body of a post....thanks
It's a Mike Smith technique, you know, helps all the lazy folks that don't want to make those extra index-finger clicks.
It's more work for you, though.
Let's say you're gonna attach two .jpg pics to a post. Go ahead and do them.
Then wait for your ISP and Taunton's servers to do their thing, and get the post up live, for all to see, attachments included. Open you own post and then open one of your attached pics.
Put the cursor in the opened pic, then click right, and choose "COPY," to put the pic on your clipboard.
Back out, then go "BACK" in Internet Exporer, so you can "EDIT" your post at the Taunton site. Once in EDIT mode, you can PASTE your copied pic into the post.
Re-do, re-do, ad nauseum, until you have pasted all your pics into the edited post. All us lazy, happy, viewers, can then see them without having to lift a finger, other than to scroll.
Duh.
Now let's see you do it.
hey.... where's my compensation for my intellectual property ?Mike Smith Rhode Island : Design / Build / Repair / Restore
A wizard!! How did you figure that one out?______________________________________________
--> measure once / scribble several lines / spend some time figuring out wich scribble / cut the wrong line / get mad
easy.. i stole the technique from somebody on BreaktimeMike Smith Rhode Island : Design / Build / Repair / Restore
Thanks....my fingers hurt just thinking about it...;-)
And I'd have to send Mike a check,....
No need to post 'Live" and edit each time..just write and attach the pics, then go to "preview" and then open the attachments, and C/P into the post after you hit "revise", that keeps you from having all the attachment icons and list of edits in the "live" post.
Spheramid Enterprises Architectural Woodworks
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Thanks to all those that contributed.
I went at it some more, and figured out that the center section of the principal roof can be trussed. This effectively reduces the loading and size of structural ridge beams, and lessens the point loads of the interior end posts. The high roof structure can be a hybrid of hand framing and engineered trusses.
The truss work can extend over all the central rooms of the upstairs of this design that don't get vaulted ceilings, and while we are having the truss plant make these few trusses, we can get the little triangles from them for the lay-on sections of the cross gables. The chimney is competely independent of roof structure. The model seen here has truss elements clearing by at least two inches.
View Image
I went at it some more, and figured out that the center section of the principal roof can be trussed.
Sell out.
<G>View Image
C'mon, Brian. A trussed roof can be a thing of beauty.
Besides, when covered up, whether handframed or done with engineered trusses, they all look the same. See?
View Image
LOL... yeah, gorgeous.View Image
Truss the whole thing and do away with all those beams and point loads in the middle of the house. What's wrong with me? I could ask you the exact same thing.
Gene are you in N.Y.S. ? R1001.5 nys code states if chimney is designed to support additional load ok , if not designed that way, they can only support their own weight.
You still need required air space clearance.
They can figure for a normal fireplace and then make it wider to make a shelf to support it the same as a brick ledge. So the fireplace will be wider than normal but it's designed to hold the structural ridge and is fireproof like I said in my other post. It's no big deal as long as it's designed right.Joe Carola
That's about what the code say's
Frightening. If you must have this, why not have a structural skin around the chimney that looks like one, but satisfies all the codes?
All the best...
To those who know - this may be obvious. To those who don't - I hope I've helped.
Maybe frightening if your site sits on a seismically-active fault zone, but our area isn't as active as yours might be.
We have earthquakes, though, and the last one, though the strongest anyone here can remember, shook some of the 150-year old all-stone chimneys so a rock or two let loose, but that was all.
Did you look at the plans at the plans seller's website? Go here and see. http://www.architecturalhouseplans.com/home_plans/133
Look close at the floor plans, both for the main floor and the second. I cannot see anything that can pick up the ridge near the chimney other than the chimney. The architect did the plans for a client that built it in Maine, but a number of copies have been erected elsewhere. Maybe not out near the Pacific ocean coast zones, however.
Not into the core.
But you have a thicker masonry mass or corbel out to support, so that one of the following exists - Either there is an inch of space between the beam and the masonry ( kinda hard to do on the bottom where she seats) or there should be 12" of masonry between the flue interior and the beam as it sets in
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Take a close look, Pif, at the plan. Only if you have the time. Go here and see.
http://www.architecturalhouseplans.com/home_plans/133
I am trying to model this house on the cheap . . . seeing how far I can get without purchasing the planset. At the same time, I am using it as another exercise in boosting my Sketchup skills.
I got an email back from the plans seller that the chimney does not play a structural role in the roof, but got no more info than that.
After poring over the relationships of walls to roof structure, I have concluded that, since there is no direct path down for the load at the near-chimney ends of the main ridge beam, there must exist a post-and-beam arrangement that uses headers and beams. The reactions are picked up and spread to the walls that parallel the main ridge. The ceilings must be flat in the central portion of the upstairs level, rather than vaulted up to the rafter bottoms, in order to conceal the post, beam, and header stuff.
Do you reach the same conclusion?
Hijack:This Sketchup program definately has some potential. Thanks for the tip.
Andrew Douglas: What have you been up to? Jim White: Killin' time... It just won't die.
http://grantlogan.net/
Look at the upper floor plan where a centered chimney would be--nada. The chase is in the closet well off to the side of the ridge beams. That's probably why the chimney is so wide above the roof line--it has to look centered while allowing clearance for the flue to pass by the ridges.
If you are building it on the cheap you definitely would be better off without a full brick chimney.
Can you incorporate a post inside the finish detail ? From the ridge to the floor system below.
U probably could. I noticed there are posts on first floor level
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Gene,
I've framed that detail several times myself... never done a three-way like that, but I have done them where the chimney segmented the ridge beam.
As long as proper clearances are maintained and the chimney is designed to incorporate this function... no problemo. Inspectors will flunk me a heartbeat for a missing piece of fireblock that the HVAC guy knocked out.... but that detail will fly all day long as long as it is designed correctly.
Am I the only one thinking that the chimney isn't really a brick chimney, but rather there's a chase running up the side of the ridge beams and it's a brick veineer box on the roof.
Gene
Am I the only one who wonders why you are showing 2 flues?
If one of those is dummy its no problem at all to get structural support all the way from the foundation. Then corbal around it to get the flue pipe centered at the roof. That whole support would be in code compliance with that size chiminey.
Jim
One flue is the stove vent, the other is for the LP gas boiler.
If you are using effiency boiler can't it be vented thru the wall?
"One flue is the stove vent, the other is for the LP gas boiler."
What's the object of this whole thread. If one of those flues isn't a wood burning fireplace or coal burning stove any thing else can be metal flued inside of eather a chase or masonry and then the rest of the chiminey space is available for structural support of the beams and is not a fire code issue.
You asked the point of the thread. Here is a clip from one of my earlier posts.
I am trying to model this house on the cheap . . . seeing how far I can get without purchasing the planset. At the same time, I am using it as another exercise in boosting my Sketchup skills.
I got an email back from the plans seller that the chimney does not play a structural role in the roof, but got no more info than that.
It is a small house, with no extra space anywhere.
Gene
Sorry, I missed those comments. I understand re: modeling skills I do all my original design in Autocad and try to do it in 3-d to catch things that aren't obvious in plan view. It really takes some practice.
Jim
I have been a big user of Cadkey, which is much like Autocad, but am now an avowed Sketchup fan.
You know it's free, don't you?
Actually, what I like to do is use the Better Home & Gardens program (its by ART the same people who do Chief Architect) for working out a design Its quick & it works well to demonstrate alternatives to HO's. Then I convert to AutoCAD flat plans if simple or 3d models if complex.
Also tried TurboCAD It seemed like a bad compromise. Dificult to work with & didn't show much