This post will probably make me look or sound like a real idiot to the pro’s around here but here goes. I built my house @4 years ago and decided to incorprate some of the newer teqniques that I had been seeing such as Ijoists, ICF,ect. So anyways I built a pretty straight forward 26’x38′ cape cod with i-joists for the 1st and 2nd floor. Then decided /was talked into framing the roof with I-joists too. I was building a stock plan from one of our local lumberyards with some changes. from what I understood tech support and engineering coming from the I-joist supplier.
Anyways after building the house and living in it a couple of years I have recently found out that the joists were used incorrectly. from what I understand with ijoists your ridgebeam is supposed to be structural I used a 2″x12″ LVL and it probably should have been somehing like a 4″x16″ powerbeam (or something like that). my understanding is that this is due to a normal rafter to beam connection does not allow the load to transfer from the top of the joist to the bottom of the joist (but I could be wrong about this). I made my connections with a simpson hanger that wrapped the bottom of the joist hooking it to the ridgebeam. I then came across the top with 1 1/4″ wide metal strapping to tie the joists to each other.
What are some of your experiences with this kind of roof framing (Ijoist). I have spent many sleepless nights trying to figure out what to do about it, to no avail. The people who I have talked to (non builders) have all told me that I worry to much and that this place is as solid as any they have ever seen, but still I worry. opinions? please be kind..
P.S. I know I should have got an archy hindsight is always 20/20
Replies
Lot of variables missing still and you woin't get definitive engineeringthatyou can count on via internet, but strong chance you do worry too much.
Howlong is the ridge beam?
is there an anchor between the cape uppr floor joists and the roof rafters in any way?
In other words, if the floor joist and the two rafters form a triangle joined at the apexs, even indirectly, then the floor jpoists function also as rafter ties, to keep the roof from sagging and spreading, provided the joints are secured enough.
Additionally, This being a cape, there may be kneewals transfering some roof load to the floor rafters. This could be good or bad, depedning on whether they are engineered to handle it.
All in all, there are a hundred ways to handle any design problem. If you built according to the joist companies plan as provided to you, you should be OK.
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i think you are worrying too much also, if anything your 2x12 lvl is just slightly undersized, and while it may sag over time i doubt it will fail. this is if you do in fact require a structural ridge which i am not sure of, i think it may not be needed.
you don't know what your limits are untill you exceed them, and just because you are sliding doesn't mean you are out of control!
if it does sag over time at a future re-roof what you do is shore up the roof on either side of ridge with temporary walls, slowly jacking to re-set to proper rafter height (1/4 - 1/2" per day). then when you happy with rafter height you go up and cut out existing ridge and replace by dropping in from above proper size beam. resecure and repair drywall and roof sheathing, then complete re-roof. certainly extra work from a normal re-roof but not that big of a deal, and again a good chance it will never be needed.
just knowing a repair plan of attack should help you sleep easier, now just wait and see how it does, and let us know as you are now a test case!
The rafters are connected to a sill on the second floor decking with a adjudstable angle bracket. there is a kneeewall over most of the rafters and the second floor rating was way above required. I also put in ceiling rafters all the way across, but I have heard the whole collar ties do nothing arguement before. The ridge beam is 38' feet long.
I'm with Piffin on this one (not enough info) but you have to ask yourself where is the load being carried. It sounds to me like you have a perfectly triangular roof cross section. And in that case, given that you have a complete second floor joisting tie and ceiling joist / ties (collar ties do actually work if they are applied appropriately), your ridge beam could possibly be nothing more than a nailer.
Who is saying that your ridge is undersized? And the really big question, are there posts (supports, framings, 2x stack, etc....) under each end of the ridge capable of transfering 1/2 the roof load down to the foundation? If that is the case, then maybe your ridge really was intended as a load bearing beam (essentially hanging the upper half of the rafters. But if not, then it could be that your roof system was intended to be supported most by the exterior walls and the ridge is really just to keep the rafters in line so that they push against each other and help everything stay in line.
I'm not an expert but this is the way that I understand it.
Rob Kress
There are a lot of complaints here that we throw around the "hire an engineer" phrase too much, but I think that's what's needed in this case.
Just how much of a problem you do or don't have is impossible to tell from here. It could be that it's no big deal. Or it could be that there are serious problems that need dealt with. We can't see any of the things you might have done well or poorly. We also can't see things that might affect the structure like dormers and such.
Forget about listening to what your "non-builder" friends say about it and have someone look at the thing who actually knows what they're talking about.
What would you say to a beer Norm?
Hiya, sailor. New in town?
I know my house is over 325 years old and they didnt use TJI's (as I am, in the additions I'm putting on) but theres NO ridge beam at all in the original structure and its been here a long, long time.
I wouldn't worry to much about the ridge beam.
If you find that you in fact you do need a stronger beam than it can still be simply done.
Be well
andy
My life is my practice!
http://CLIFFORDRENOVATIONS.COM
Of course, your rafters are solid oak, lapped and pegged...
Pete
Brad
Course they'r lapped and pegged but most timber framed homes are not oak necessarily.My life is my practice!
http://CLIFFORDRENOVATIONS.COM
Off topic, but I thought the majority of houses of that vintage were framed with white oak. No?
Pete
and his walls lean out two feet
LOL
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As said above, it is difficult to comment on your exact situation without having all the details.
Think about this though. When framing a simple gable roof with conventional lumber, although not done very often, it is perfectly acceptable to use a 1x10 or 1x12 ridge board, provided that the rafter pairs line up. In other words, each rafter on the front of the roof needs to be perfectly aligned with a rafter on the back of the roof.
Also, I'll bet that each of your floor systems and the roof came with a construction sheet(s) generated by a rep of the material manufacturer specifically for you house. These often have an engineers stamp on them too.
Really though, I don't see why you are concerned about this unless you are experiencing problems. Now that the structure has been in place for several years, lumber has dried out, etc, get out a extension ladder and sight down the ridge of your house. If it is fairly straight, with no pronounced sag, forgetaboutit!
"When framing a simple gable roof with conventional lumber, although not done very often, it is perfectly acceptable to use a 1x10 or 1x12 ridge board, provided that the rafter pairs line up."
But these aren't conventional rafters. The rules are different for I-joists. The web is very thin, and not made to be in compression like a conventional rafter.
"I don't see why you are concerned about this unless you are experiencing problems."
That fact that you've gotten by with something for a few ywears is no guarantee that there won't be problems in the future. You never know when you'll get that 100 year snow, or a roofer will pile too much stuff in one place.Would you like a beer Mr. Peterson?No, I'd like a dead cat in a glass.
I've used them before. Can't remember all the details, but we installed them just like the manufacturer said. Blocking between top and bottom chord is a must. Top, bottom, and where collar ties attach. No birds mouth allowed. If they followed the rules, shouldn't be a problem. They seemed a little fragile to me, but they sure made a flat straight roof.
Do you have any kind of blocking to fill in the tails of the "I" joists where it meets the floor/wall and the ridge?
I used 2 pieces of osb on each side to build up the web, glued and nailed in. This was acceptable per the framing details I had from the manufacturer. Everything I did was acceptable as far as the generic (not specific to my project)joist details sheet that I got. A Ijoist rep did not come out, the lumberyards manager was in contact with the joist supplier, all I got was secondhand. there were no birdsmouth cuts made in the joists. everthing seemed copasetic (sp?)until I started hearing online and then in several magazines and then in other additional literature from Ijoist manufacturers about how they had to be installed over structural members. There is absolutely no sign of faliure, and its withstood over 80mph winds (60mph sustained) the fourth snowiest winter around here in recorded history, the pitch is 12/12 it would take a h*ll of a snow to accumulate on it anyway. I would like to get a engineer on this to reassure me but there is a pretty serious money obstqacle in the way. anyways great responses keep em coming, please.
I don't think you have a problem at all - but for all you know I'm seven, sitting here in a pile of poop - so take it for what it's worth.
Before you spend money on an engineer - I'd ask the lumber yard to have a technical rep from the joist manufacturer [i.e. TrusJoist or whoever] they usually have good people willing to do just this. Or just call one.
based on everyuthing you have reported here, you got fairly good specific advice and planning for your job from the seller and are worried because of generic advice from competitors. I see no reason whatsoever to worry. TJImanufactuers do not like their product missused or mis-sold so the retailer who sold it was doing so under their umbrella.
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I'd get the reps phone number and ask if the joist hangers below and the straping across is good enough.
I'm willing to bet a case of cheap beer the answer is yes.
Who's in ....
let the betting begin.
Boss Hog ... you taking the "against"?
JeffBuck Construction Pittsburgh,PA
Artistry in Carpentry
I'm with you so if Boos is agin' the odds are 2-1 so far
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Not a big night in Monte Carlo, is it?
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Jeff, there's no way in hell the I-joist supplier is gonna say these are O.K with no ridge beam.
I've been in this business and dealt with these guys enough that I have virtually no doubt.I recently went saltwater fishing. I came back with 12 gallons.
but Boss, there IS a ridge beam.
It is the size and the connections to it that the owner questioned.
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" but Boss, there IS a ridge beam. "
I don't consider a 38' LVL to be anything but a nailer, or ridge board. At that span it has no structural value to speak of.I was once arrested for walking in someone else's sleep.
would it be reasonable in your opinion that I would be ok if the LVL were supported by load bearing interior walls at roughly 1/3rds of its length? It would be fairly easy to accomplish this. Just a little more history on this, when I ordered the joists from the lumberyard (when I was building), I was originally told that I would need a large beam to carry the load. new to this type of framing, I asked why. was told thats what the I joist guys were saying. I then asked if the kneewalls would make a difference or not. I told them that there was no way I would be able to install a large header up at that hieght since I had no crane or otherwise, and if the beam was necessary I wouldnt use them. Well he makes a phone call comes up with these hangers and says the LVL is OK. I might add again that there is no paperwork to substantiate that I did what I was told or did not. Lemme guess, I got f**cked.
"would it be reasonable in your opinion that I would be ok if the LVL were supported by load bearing interior walls at roughly 1/3rds of its length?"
It might be. Depends on a lot of things, like your loading requirements, brand of LVL, exact bearing points, where/if you have dormers, etc.
It would cetainly be a lot CLOSER to working that way.Ex-wife for sale. Just take over payments.
So you let us go on all this far and only NOW tell us that you DEMANDED a smaller beam than was in the design....
Based on all thoise phone calls, maybe it is OK with the setup you have still.
But if you got f**ked, you did it to yourself so don't be blaming anybody else cause they presented you with a plan and you said "No, I can't do it that way"
Now you are asking for engineering specifics about the retrofit you are proposing and you could STILL be hoilding back important information. Still trying to screw your self?
If you transfer load to the walls, you need to make those walls structural. That means that the floor joists they are on need work in the webs and the walls under need to transfer loads to foundation.
I still think you are better off not messing with it. You already said that it has weathered the worst possible with no flaws.
But if you are insistent on doing something, you need to go back to one of the first replies here, Get an engineer on site. otherwise, you could do more harm than good.
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either way .....
we need an engineer on site!
Immediately ....
there's a case of beer riding on this ....
we need facts ...
not conjecture!
We're talking a serious subject here ...
I may have to pay for a case off beer ....
these are times not to be taken lightly .....
JeffBuck Construction Pittsburgh,PA
Artistry in Carpentry
"So you let us go on all this far and only NOW tell us that you DEMANDED a smaller beam than was in the design...."
I did not demand a smaller beam, I simply stated to the supplier that if i had to use a beam that size for these joists, then i would not be able to use them. I would have then just framed with conventional lumber.
"If you transfer load to the walls, you need to make those walls structural. That means that the floor joists they are on need work in the webs and the walls under need to transfer loads to foundation."
where i would transfer these loads are load bearing and floor framing is built with LVL instead of joists due to a stair opening.
Im not trying to agitate anyone with this post, but feel I am in a real quandry. I explained my layout to the supplier very well when I bought these joists. But without any paperwork to back up my position I know that I will be unable to get any assistance in resolving the situation from the lumberyard who supplied them, and I suspect from the manufacturer either. On a side note took a trip up into the attic today for a looksee and everything looks great. thanks again for all the input.
" I did not demand a smaller beam, I simply stated to the supplier that if i had to use a beam that size for these joists, then i would not be able to use them. I would have then just framed with conventional lumber."
Same difference. To paraphrase - "make these work with a beam I can use or I take my business elsewhere"
" i would transfer these loads are load bearing and floor framing is built with LVL instead of joists due to a stair opening. "
You still seem to be missing the point of basic engineering here. Those LVLs would have been designed to handle the load that they are handling - the floor around the stairwell - and not any more. You can't assume that because they are LVLs that they will hold up anything that you want to transfer onto it. You need to transfer that load all the way to foundation and thence soils, or you need to find an engineer to determine what the loads are you would be putting onto them and whether they will handle it, and then follow his dictates to a T.
I'm not trying to be abusive here, but it is getting frustrating. You have something that appears to have been designed by or with assistance of engineering standards and now are secondguessing it, but you want to proceed with no engineer. Go ahead it you want but you could end up damaging even more of the house when there is nothing wrong now, apparantly.
I may be overly frustrated about this, but I have buiolt specially designed unique things and then had the owner call a few years later to fix what they broke by messing with something they should never have cut into.
Put a load on those stair LVLs and you can find your floor suddenly sagging, the ceiling cracking on joints below it, the doors near it not fitting or swinging from being now unlevel, the floor squeeking, the paint cracking, and the wife complaining...
or
maybe not
only your engineer knows for sure
after you call him.
Me - I'd ignore the whole thing. If it ain't broke, don't fix it!
And get on with your life and enjoy the house. Sounds like it hgas a lot of poisitives.
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I am very sorry if I am agitating you over this. believe me it was not my intent. I do understand what you are talking about with the LVL The point where I would be putting the supports are where the LVL crosses a load bearing wall. But I believe that you guys are correct in your advice on contacting the manufacturers Rep. I got that phone # from the Yard yesterday. I will try and contact the right people next week. Im sorry if I frustrated you piffin, this situation has been a very troublesome thing to me, here I thought I was overbuilding the roof, and instead found out that I may possibly have put myself into a expensive, frustrating situation. I will try to update you guys on what I find out, I sincerely do appreciate the advice.
And I'm sorry to have sounded too overbearing, but you can see my sourcce of frustration when here again, you have more information to add with the wall under. Incomplete information from your end keeps me working in the blind.
Oh well, Good luck
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"Incomplete information from your end keeps me working in the blind."
Not trying to pick on you or this guy here, but...
That's why I generally stick to the "somebody needs to come out and look at the thing" line. The HO may be competent, a complete moron, or anything inbetween.
They may or may not have given us all the pertinent information.
There may be problems that they don't know about or even recognize as problems.
There may even be things they don't know about or understand that HELPS their situation.
I really, really don't like to give out specific advice for something I haven't seen.Knowing you has put a song in my heart. But the fat lady in the viking helmet is really starting to annoy me.
You were right. Of course, I was too, if you eliminate most of the "discussion" portions and boilit down to "either get and engineer OR get happy with the one that already planned it"
;)
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Talked to the manager of the yard were I bought them today. He is the one who sold them to me in the first place. He said he vaguely remembered the sale. I thought he acted a little cold toward me but I may have misread that from him. This is a guy that I have been a aquaintance of for prolly 7-8 years and we get along pretty good normally. His comment was that I should definately not lose sleep over it and he thinks its fine too. I informed him that while I would like to just assume that it is OK that I cannot, and need it to be looked at by someone with more extensive product knowledge. He agreed to contact his I-joist rep. and discuss it with him, he thought he (the rep)would prolly come out for ####look. He said if it was over the reps head they would prolly send someone else. Maybe this will work out well. Man I really hope it turns out that they properly engineered it and I dont end up with a lotta expense and hassle to fix. Anyways I will try to keep all interested posters informed as soon as possible, as was requested... thanks.
Thanks for the update.
I'll be very interested to hear what the guy has to say, if you don't mind letting us know.Alimony, n.: Disinterest, compounded annually. [Walter McDonald]
I will let you know.
another update.
I called the yard manager today as it had been a month and had not heard from him. he told me that the engineer for the Ijoist supplier that they are using now (not the one that supposedly engineered it to start with) would call me that day and talk about my application to see if there was a problem with it. Anyways the engineer calls and we go over my application and it sounds like it is not even close to correct. tells me that he doesnt know what the heck the original guy was doing. said i should be seeing alot of drywall cracks and stuff already (which I have some but not alot ). He then calls the yard manager to explain the situation. he calls me back about 45min. later and says ok it sounds like there is a problem, then asks me where I think we should "start". He told me that he needed me to search through my records to see if I can find out where the yard ordered them from. I have the reciept for the Ijoist "system" listng the components indiviualy from the yard but all I could tell him was they were made by all-joist. I think he is trying to find out the source of the likely bad engineering to help place blame/liability. Does it sound like a good idea at this point to consult an attorney? The corrective action could be very expensive and I sure dont see how this could be my responsibility. please comment, i have greatly appreciated everyones input on this subject.
I don't know that you need an attorney yet. Whomever did the engineering may be willing to take care of things.
I would definitely document everything. Don't give up that ticket from the lumberyard you bought the stuff from. (Give someone a copy of it if they want it) Make notes about phone conversations and other contacts.
Hope it all works out for you.A bug in a computer program can be changed to a feature by documenting it.
another update.
we have since faxed out drawings to the I-joist maker (and supposedly the engineer) of my roof. they cant really find anything, related to my job, and they also tell me that it is not right. the yard manager got snippy with me about it saying he would have never had anything to do with it with out sketches of my layout, I reminded him that i was building one of thier (the lumberyards) stock homeplans and that the only change to it was lengthening the back dormer which the reciept plainly shows was understood. well he went into this "what do you want me to do about it 'cause the engineers probably wont take any blame for it" he said something to the effect of what do I want the materials to fix it for free? I told him that a structural engineer needs to come out and come up with a working plan to correct and then it will need to be fixed and someone other than me should pay for it. he said that he wont take responsibility for this fiasco. My wife wants me to call the lumberyards corporate offices and complain I am leaning toward an attorney. I will probably have to pay out of pocket for the engineer but then I can always try to sue for that later. this whole thing sucks....
AJ, You're making good progress without an attorney.
You have the yard manager agreeing there is a problem, you have the manufacturer's engineer agreeing that there is something wrong.
The yard manager isn't the top of the food chain, so there's still hope there.
My advice would be leave the attorney on the bench until such time as necessary and spend a few hundred on an engineer instead.
If you decide an attorney is needed, he will want an Engineer's report outlining the problem and solution required/desired, whatever you want to ask for.
Once there's an attorney involved, there will be three attorneys (at least) and there'll be no getting rid of them.
They may end up with a final result that does not fix the problem and no further recourse. They will all get paid, you may get........
Free advice, Internet consulting too.
Joe H
Edited 6/28/2004 2:38 pm ET by JoeH
here should be the last update (most likely). An attorney recommended that I go ahead and contract a structural engineer to formulate a plan for correcting the misengineering. that way we could then contact contrtactors and get qoutes to have it repaired, so I would have a Idea how much to file a suit for. Well I have had what I thought was a good way to fix this that I had been working out in my head for awhile, so when the engineer came to check out the house I asked him about it. Seems because I used LVL to frame my open foyer and because I build my non-loadbearing walls with double top plates I had unknowingly laid out all the groundwork for the fix. he ran all the numbers for the loadings and all I had to do was put in posts under the ridge at the right spots (both sides of my open foyer), and I am fixed. took me all of about three hours on a sunday to put this mess to rest.
I still havent got the bill for the engineering, I think I will take that to the lumberyard and see if they will pay it. they prolly wont but if they do then I would consider shopping there again.
thanks for all the advice I recieved. It is such a relief to finally not have to worry about this everyday. All of a sudden my motivation to get back on all the little unfinished projects has returned. what a long ordeal this was for me.
Great, the less lawyering the better.
Joe H
Glad to hear it worked out! It would appear that you found yourself an engineer worth their salt. Better money spent on an engineer than a lawyer, anyway!
Thanks for letting us know how it turned out.
I'm also glad that you didn't have to get lawyers involved.I think men who have a pierced ear are better prepared for marriage. They've experienced pain and bought jewelry. [Rita Rudner]
Based on what you've said farther on in the thread, I stand by my first recommendation that you need someone to come out and LOOK at the thing. As you've seen, there's no way you're going to get a definite yes or no answer here. You're just beating your head against the wall arguing with everyone.
If you don't want to hire an engineer, talk to the place you bought the I-joists from. Tell them you have questions and want to talk to a rep from the I-joists company. They have people who do stuff just exactly like this.
The manufacturer's rep may help you or may not. But heck, it's free. And since he can actually SEE your structure, he'll have a better perspective so he can make suggestions about what does/doesn't need done. He certainly may tell you that you need an engineer. But he might not.
Regardless, you'll have someone looking at the thing with extensive product knowledge. And hopefully your blood pressure will end up being lower over this whole thing.
And please let us know how it turns out. We have lots of threads where we give advice and then never know what happens.My mind not only wanders, it sometime leaves completely.
Round here the TJ suppliers won't sign off on warranty until they have made a satisfactory final physical inspection of installation. Our local guy is very thorough and particular which we appreciate (usually) since we know the product will perform according to its engineered standards.
Did a commercial roof last fall that was TJI rafters @10:12 pitch. It was PSL ridge beam supported (5.25 wide x 12 deep, 24' spans) and used Simpson straps to tie the top chords together at the ridge, with web stiffeners toe-nailed to the floor joists for base anchoring. Jack rafters were fastened to valley beams (PSL) with adjustable metal Simpson hangers. This was a commercial job and had a structural engineer on board due to other solid timber post and beam work.
You're right. I joists are an engineered system and if they are installed according to the supplier's specification for the current application, they are fine.
Wally
Lignum est bonum.
you said an engineer came out from the IJoist place ...
so where'd you finally get the idea that the roof is wrong?
from the view I can get from here ... looks ok to me?
missing squash blocks ... cut in birdsmouths?
What set off the alarms?
Jeff
Buck Construction Pittsburgh,PA
Artistry in Carpentry
Looks really good from here, especially when I close my blind eye, and squit just right out of the other two...
;)
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Whoa! Did someone say collar ties are useless?