Contractor Talk - Professional Construction and Remodeling Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
8,573 Posts
Discussion Starter #1
I can't for the life of me figure out what the architect was thinking! I spent 3 hours today with a superintendent of a job site and the framing carpenter. We were all staring up ath the the ridge of the roof, from inside.

Our discussion consisted of "how the hell do we ventilate this atic?"

Let me explain. The rafters are 2" x 4" 16 oc. They have a 3/4" cdx nailed ontop of them. OK here's where it gets funky. ONtop of that there is another 2" x 4" nailed. Between this first piece of plywood they are going to put typical fiberlass insulation r13. They are going to then put a 1/2" cdx roof deck.

The soffit vents ventilate into the attic. The air in the attic space has no way to exhaust!

I've thought of a few options here: 1) cut an opening in the ridge of the first deck so the air can circulate out of the opening in the second deck. 2) install a gable vent with a power fan and put no roof ventilation other than that.

I don't have any clue what the architect was trying to accomplish with this because the attic will be unfinished trusses. They woudl be better off insulating the ceiling joists.

Oh yeah lead architect is on vacation, so is the GC. We are scheduled to start tuesday when I will be on vacation, and my boss will be managing the project.

I sent my concerns via fax to the GC and site super and maybe tomorrow I will send the architect as well. Problem is the framing (secondary ontop of trusses) is already in place and waiting for insulation which was delivered yesterday. This means the carpenter is going to have to undo 40 something rafters.

I won't make any more or less by doing this right, unless they ask me to undo the carpenters secondary rafters. I just want the roof to last as long as it is intended to last. This is my first project for this GC and they are a very large and organized GC.
 

·
Registered
Joined
·
11 Posts
Perlin roof systems are excellent insulator for all sorts of climates, but work the best in cold areas. There are efficient ways to vent them (see commercial specs for panelized roof systems). 2 X 4 rafters with perlins on top???
 

·
General Contractor
Joined
·
1,035 Posts
I think orto mean purlin which is essentially roof "sleepers" running perpendicular to the main roof trusses. It's more prevalent in post & beam.
Of course in your situation it would require another conversation with the architect :eek:
 
1 - 4 of 4 Posts
Top