I have a customer that want me to remove a whole house fan and replace it with a pull down staircase. Heres the problem the roof is a truss system. he wants to use the attic for storage. This truss had already been cut when they put the fan in. My question is can I cut it another foot to install the stair? My plan would be to frame the opening with 2×6’s and to bracket the cut ceiling joist to the new framing.
The house is a colonial and there are wall on either side of the cut(I know trusses dont rely on interior bearing walls). Is there anything else I might want to do? Maybe reinforcing the rafter in question by sistering a 2×6 and adding a collar tie? BTW i’m only talking about cutting one truss. Unfortunately I couldnt gain enough access to the attic to tell if the trusses are 16o/c or 24o/c.
Any advice would be appreciated.
Replies
Take a pass on this job.
You already (should) know that cutting trusses is a NO-NO.
And if you insist, the original truss engineer is where you should go to get a redesign of the truss system to compensate for the already cut truss and any further work.
I'll bet you aren't carrying nearly enough liability insurance to play this game.
Actually I do know cutting trusses is a no-no. That was the first thing I told him. The truss is already cut though, as I said, someone cut it to install a whole house fan. This is why i'm wondering if I can strengthen it by sistering it? After discussing my concerns with the homeowner he said at very least we need to lose the fan.
Any idea how to locate the truss manufacturer?
Edited 1/15/2005 11:18 pm ET by MSA1
This is a sticky situation.
I would do my best to find out if you can get the truss company or an independent engineer to determine what the proper fix would be. If you can do this and make the structure conforming, go about your business.
If you can't get someone with a stamp then you have a decision to make. The damage is done whether you get involved or not, so one thought would be you are not likely to make it worse.
On the other hand, if you touch the work you now own it and should be willing/prepared to take all responsibility for any problems that might arise.
Definetely proceed with caution.
Jon Blakemore
Jon, that is exactly what I was thinking. I think I need to call an engineer on monday. Thanks.
The other issue is that unless they are storage or attic trusses they aren't designed to carry anything other than the weight of the DW and insulation.
I did a thread once called Cutting trusses for skylights that is more or less relevant. It explains the design problems with cutting one truss and trying to reinforce it.
Sounds like you're on the right track though if you're gonna call an engineer. This is definitely fixable if the engineering is taken care of.
There's one other thing that bothers me though - WHY do they want an attic stair? If they plan to store stuff up there, the trusses most likely aren't designed for that.
I said, "I didn't know there were any witnesses. Now I'll have to kill you too."
The storage thing was what I was concerned with also. I don't really think cutting one truss is gonna be real bad. It's already been cut for how many years anyway.
Them freaking toothpick trusses are so close together that using the attic for storage will annoy you more then help you. That's one reason I don't like them. Another is trying to manuever my "Dense" azz through them in the summer trying to run wire sucks.Who Dares Wins.
I'll bet the HO just wants to get rid of the house fan and thinks a set of stairs would be a practicle hole filler.Who Dares Wins.
Here is a potentially stupid question... Do you ever do roof trusses on houses that are other than 24" O.C.? If so, how about a swag at how often... 5%, 10%? Matt
Probably 99% of the jobs I do are 2' O.C.Every once in a while I do a job that's 16" O.C. There's one small town in particular near here where everyone seems to do them at 16" O.C.I've done one job in 20 years where they wanted the roof at 19.2" O.C.Is that what ya wanted to know?
Ask people why they have deer heads on their walls and they tell you it's because they're such beautiful animals.
I think my wife is beautiful, but I only have photographs of her on the walls.
thanks. I had just never seen any roof trusses at anything but 24" OC.
If that is the case for this guy's situation, truss cutting wouldn't be in the equasion, and even so, I wouldn't touch the job with a 10' pole unless an engineer was involved.
Something tells me though that the HO isn't gonna wanna pay for that and the situation is further weakened by question as to if the trusses are designed to support any storage. Matt
boss-
how would you be able to lay out the plates for 19.2?
lol
I'll bite!How?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
trick question??
pull 18 1/2" and set ahead. 8ft will break.
I didn't do it....the buck does NOT stop here.
He did use the lol, but it were in fine print. Neat little trick getting that black diamond question snuck in there backwards like that
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
yeah,yeah...enough about that, trying to figger Gunner's 'right triangle' formula.<wink>
I didn't do it....the buck does NOT stop here.
I think you use one of these
Jon Blakemore
Nope you use this simple formula and Vola there you are.Who Dares Wins.
"how would you be able to lay out the plates for 19.2?"
Is that a trick question? I wonder every time someone brings up the 19.2" O.C. layout thingy...
But just in case you're serious (Or if anyone else is wondering) The black diamonds on tape measures are 19.2" O.C.
Hermits have no peer pressure.
i was talkin about the black diamond thing without saying it lol
so yeah i guess it was a trick question
Edited 1/17/2005 1:33 pm ET by bud
Sometimes it's hard to kow if someone is kidding around or not. I really wasn't sure. But I decided to answer the question as if it were serious, as there are probably a few folks reading who don't know what the black diamonds are for. There are a couple of threads a year here asking about it...
I doubt therefore I might be.
They want the stair for storage. I dont think its gonna be practical to use this attic for storage. The homeowner did say that even if we cant do the stair he does still want the fan gone.
More likely than not the trusses are spaced at 24 OC. If thats the case you can by a drop down stair to go between the trusses. Find another spot for it
Then.... Dont touch the breached truss without an engineers stamp even if you want to repair the bottom chord. You touch it you own it!
Remember the bottom cord is there to hold the rafter ends together, it theory, its not resting on any interior walls. Hence cutting the cord is not good!
I realize the bottom cord is in tension. I was surprised to see it cut. Sounds like I probably shouldnt put the stairs in. I'll still contact an engineer on monday. Theres no way i'm gonna be the last one to touch/cut that truss without an engineer to sign off.
Cant afford that liability.
Unfortunately I couldnt gain enough access to the attic to tell if the trusses are 16o/c or 24o/c.
Kinda helps to have all the info to know exactly what the job is gonna be, don't ya think?
How do U know the truss has already been cut if you can't see in the attic?
I'm confused here ....
btw .... a stud finder run across the ceiling would answer that Q pretty quick ...
as would standing on top of a 6ft step ladder and knocking on the ceiling.
Me ... I'd confirm my suspicions that the trusses are like all the other trusses on the world and are 24oc ... then ... I'd find a convient spot away from the lawsuit-cut trusses and install the drop down's like I always do.
btw .. my contract .. written up seperarately for the removal of the fan would state quite clearly that the fan saw set between previously altered trusses ...
Jeff
Buck Construction
Artistry in Carpentry
Pgh, PA
Jeff I can tell the truss has been cut because I can see it through the fan slats. You're right about not being able to go up in the attic. I've no reason to believe the truss arent 24 o/c.
There really isnt any other place for the stairs to go and the more I discuss this here I think theres less chance for storage in this attic.
Edited 1/16/2005 10:01 pm ET by MSA1
even the lightest trusses can handle the occasional box of XMas decorations ...
plus ... attic access is always a good thing .... check for roof leaks ... reinsulate ...
that sorta thing.
Jeff Buck Construction
Artistry in Carpentry
Pgh, PA
I told the homeowner this might not be the best idea. I still have to check with the engineer, he was not in the office today. H/O understood my concerns about cutting the truss and if the engineer says no maybe i'll build him a shed this spring. :)
And then, once you get the stairs in there, the homeowner will say: Can you please cut some of these diagional 2x4s out of the way so I can put more boxes up here? Matt
We'd have to cut the diagonals to get the hottub up there. Oh yeah the sky lights too. :)
What about the water bed??? ...Matt