Questions about finishing an attic space

[Exterous]

I've got a fair bit of unused attic space above my garage that butts up against our closet and master bedroom. I was thinking about breaking through the closet to extend it further. I've got about 8' until the garage attic access and\or the normal ceiling height butts up against the roof.

Electrical, flooring, drywall etc I've all done before but I've never messed with roof bracing. Anyone ever done anything like this before and have some tips on how to go about making sure my roof doesn't fall in?

From attic access towards existing closet wall:


Picture up towards roof showing 4 of the 5 braces that would need to be modified:

 

[boomerang]

I wouldn't mess with trusses without having somebody onsite to take a lot of measurements so that they can tell you how it needs to be dealt with. Trusses are engineered to handle the loads imposed on them and altering them by removing and/or relocating components can lead to disaster. The vertical members on top of your existing closet wall are part of those trusses too. You've got some hairy shit going on there. In this case that's a technical term.

My guess is that a structural engineer will have to be involved and he or she won't be able to give you answers on that initial trip.

 

[Greenman]

Don't ever cut a truss cord. You need an engineer to look at it and decide where you will have to add framing and plywood webbing.

 

[edro]

Ever play one of those bridge making games?
It's pretty interesting how large of an impact removing 1 stick can have.

 

[Exterous]

Thanks guys. I wasn't planning on removing any but instead moving the support from the existing ceiling joists to the new ones on top of the finished room and then maybe bracing the side wall to the garage ceiling joists.

I'll look into getting an engineer to take a look at it

 

[DrPizza]

I was trying to avoid an engineer in a previous thread about beams (done with that project, btw.)

But, trusses - you don't mess with trusses without engineering. They're generally designed for the intended loads. A floor and live weight probably wasn't intended.

 

[WHAMPOM]

Trusses are designed to use the least amount of materials to hold their load. Modify the rafters? You are going to have to put in a floor, joists 2x10 or 2x12 on sixteen inch centers from bearing wall to bearing wall and move a lot of wiring to do so. Are those on 24 inch centers? You may have to rebuild the whole thing to meet code.