Expert: Stephen Major - 8/11/2007

Question
Hi! I'm designing a house with 9' ceiling heights throughout.  I want to have 16" transoms over some of the windows. The top of the transom would be about 96 1/4" from the floor (11 3/4" from the ceiling) Is this possible?  I'm concerned about a couple of things:  First, with a roof pitch of 1:10 (using trusses and scissor trusses), will the roof overhang & soffit interfere with the windows?  Second, is 11 3/4" enough space for headers, top plate, etc?  If I have to, I'll increase the ceiling height a little if that's possible without incurring a lot of additional expense.  Thanks in advance for any advice!

Answer
Laurie,

As part of your design process you must draw the wall/soffit in section detail and work these issues out.  

At first glance the roughly 12" space is adequate to accommodate the roof overhang, but it depends on truss heel height, the amount of overhang, the width of the fascia, and of course the roof pitch.  The 1:10 you describe is nearly a flat roof.  Is this correct?  Roof pitch in the U.S. is normally described as rise in inches against 12 inches run, such as 4:12 or 8:12, for example.

Header depth requirements depend on opening width, wall thickness, and of course loading.  If necessary simply specify LVL headers if solid wood will not meet the structural requirements.  If you are not comfortable specifying headers, consult with an architect or engineer.

--Steve Major