Modify trusses?

[gssstuff]

There is a small room that was added to my house but never finished off. My plan is to finish it off as a sunroom.

The drawback is that the room (12x14 - 5/12 pitch roof) has trusses that are designed with a flat ceiling and my wife would like it to be a cathedral.

The span the trusses cover is 14'.

Would it be possible to sister 2x6/2x8 as rafters to the trusses and create the cathedral?

I have no interest in tearing the existing roof down, the house is less than 5 years old and needless to say, I don't want the additional expense of a tearoff.

Thoughts?

[Michael Bulatovich]

Nope. You have to frame a conventional roof, using rafters and collars, or rafters and a supported ridge beam.

[dpb]

Not sure what you're really suggesting -- if you mean to remove the trusses, the answer is certainly "no" w/o framing a whole system to provide the roof and thrust support. If you mean to simply add a cosmetic "rafter" and leave the truss to an open area to the existing roof instead of putting the ceiling on the underside of the existing trusses, don't see why not (although I can't imagine it would be particularly attractive).

[CWatters]

The horizontal parts stop the roof pushing the wall out. Best leave them alone.

You could still have the open ceiling. pain the trusses a light colour as the cathedral ceiling. Can look quite nice - sort of colonial.

[<moo]

the size of the lumber used in a truss is not up to spec with a conventional stick framed roof system if you cut into and modify the truss you take away ALL the strength of the system so you cant just modify it

and the metal staple straps that make the connections are put on with a press so even if you could get a couple you cant just hammer them on :o)

and usualy the truss wont line up the same way on the top plate of the walls as a conventional roof so you wont have room to sister on those rafters

just tare it out and get new trusses it will save you a lot of headaches and time

you are talking a day vs maybe 3 or more dealing with that mess

[kickstart]

Should be no problem . Get an engineer to design it for you. I have done several jobs like your suggesting and am planning another just like it. Check you attic area for ducts and wiring that will all have to be moved, this can add considerable expense and planning

kickstart