I have a project for a friend coming up its an addition.
It is a two story home with a hiproof. Attached to the end of the home is a two car garage which also has a hip roof. The ridge of the hip roof is about 24′ long and I need to put a small 10×12 walk in closet addition against the home dead center of the ridge above the garage . The garage has roof trusses as far a I can tell because the free span ceiling in the garage is 21 ‘ feet across with no supports.
When its time to cut my addition into the garage roof what would your plan of attack be?
My thoughts are to install my beam and posts to support my new floor first from the inside removing some of the ceiling in the garage to get this done. I could leave the ceiling supports in as my floor for the addition will be higher. I thought I could just sister up against the current ceiling supports created by the truss . Once its time to start my walls the upper portions and webing of the trusses would be in my way. Cutting through all of them and then framing my walls does not sound safe. Am I worried for nothing? should all the rack streanth of the surrounding truss work and sheathing be enought to kepp alll well?
Any ideas on the approach?. Should I install my wall studs one at a time and nail truss members to the wall studs one at a time? I would much rather have the truss members leaning on a ledger against the wall studs myself but cant see a way to get er done safely. With ten foot out, I believe I’ll be dealing with the first five to six trusses from the home above the garage.
Replies
This is more or less a "bump" (just a non-answer to keep you posting "fresh" so it can be seen by others), but I wouldn't do any modification to any truss without having an engineer look at it. Modifying trusses without knowing the engineering is a good way of getting someone hurt. Maybe Boss Hogg will see this and respond--he designs trusses for a living--maybe you could even post to him using email. (Not sure he allows direct eemail--some people here don't.)
>> The garage has roof trusses as far a I can tell because the free span ceiling in the garage is 21 ' feet across with no supports. <<
That doesn't mean that the roof is trusses at all. It could be trusses but it can also be stick framed. I've stick framed many garages with that span.
Either way you have a lot involved. There are a million ways that this can be done. How come there's no Architect involved to figure this out? Do you need one in your area?
I have two thoughts if you are planning on using those trusses in any manner at all.
1) Hire an engineer or architect
2) Hire an architect or engineer
As Joe said, you can't know for sure that you have trusses until you put an eyeball on them.
Also, what is the length of the garage? You say the width is 21' and the hip ridge is 24'? Unless you have a bastard hip, I'm thinking your garage is at least 34' long. Is this right?
I think you're idea of installing the floor framing before cutting trusses/rafters is a good one. If the garage is only 21' wide, you will only have 54" of span to support when you start framing your walls, so this should be manageable. I would just put some temp framing in from your floor joists to the bottom of the truss top chord/rafter to support in the interim.
Can you get some pics or post a drawing?
Jon Blakemore
RappahannockINC.com Fredericksburg, VA
yes , I will get some more info this week and try to get some pics. I will draw the plans if I feel comfortable enough . This way I can save them a few dollars but only if I am sure of myself.
How could someone get away with a 21 ' span with no supports for ceiling joists?
Yes the garage leangth is about 34' the garage roof is a 6 pitch roof. Ill get more info by weeks end.
Floor support if trusses before cutting sounds like a good idea to me.
Now if they are not trusses can the ridge beam be cut to allow the addition to be framed in? Since its a hip roof the two hips rest on the beam and I assume put leverage on the ridge beam leanght wise against the house wall now. By cutting the ridge beam ten ft from home then framing is this a problem? Or is most of the weight against the ridge and not the home?
The IRC 2003 says that 2x8 SYP #2 can span 23'4" spaced @ 16" oc with a live load of 10psf. When you're not putting any weight on the members, you can span pretty far.It may not be a bad idea to put a temp support under the ridge/hip intersection to take any possible loads you introduce when you cut the ridge. I have never worked on this situation before, but my guess is you won't have that much force pushing on the ridge if you have plywood or osb sheathing. With continuous sheathing, the hips will be pushing against the ridge, but every hip jack is tied to the wall plate and then to the hip so I think you have an effective diaphragm that would help take the force away from the ridge.Better safe than sorry, though.
Jon Blakemore RappahannockINC.com Fredericksburg, VA