Can You Modify Trusses to Finish an Attic?

Carl, I currently live in a home with an extremely high roof.
The builder didn't use a truss so that area could be finished into an upstairs.

Is there a way to engineer/rig those trusses without having to replace the truss so that the area could be finished? If so, what kind of contractor would I need? Thanks, Evan

Hi Evan,

I’m a little confused.

If the “builder” didn’t use a truss (trusses, or truss system) then you probably could find a skilled carpenter who could reframe the attic.

Larger floor joists (the ceiling joists of the rooms below) may be required as well as larger roof rafters.

A structural engineer (check your Yellow Pages to locate one) should be employed to design the changes.

If in fact you do have an engineered truss system for your roof then, other than tearing the roof and trusses all off and rebuilding, I don’t believe there is anything you can do to make an attic.

Truss systems are in constant tension and compression and cutting them or putting weight on the truss members where no weight was designed to be will cause them to fail.

Here again, a structural engineer could take a look and advise you.

A truss system designed for attic space is pictured below. If you have to tear the old roof apart, this truss system could possibly be used for a faster and less expensive rebuild.

Image courtesy of Universal Forest Products

Good luck,
Carl Heldmann,

PS. Be sure and read my article, Roof Truss Calculator - Roof Trusses