Low slope roof with vaulted ceilings ventilation and insulation questions
I could use some advice for an upcoming roof replacement on my early 60’s built house in climate zone 4A (Southcentral Kansas). My current roof is a 2/12 torch down modified bitumen that I’m thinking about replacing with standing seam metal, or go back to modified bitumen if metal ends up over budget limits. Currently my house has continuous soffit vents with no ridge or gable venting, and I don’t beleive the “attic” is insulated, it’s not accessible (without putting holes in the ceiling) so I am not certain if it is or not at the moment. I was thinking of adding insulation above the deck with the new roof install hoping to quiet down some outside noise (it’s a bit noisy during heavy rain), and also add some insulation value to the roof assembly.
My main questions are:
Will above deck insulation add any R value to the home since it sits above a small vented attic space, outside of the envelope?
Are continuous soffit vents which are sized appropriately (over 1/150 sq.ft. vent/attic) sufficient assuming electrical boxes, etc. are sealed well?
If insulation above deck is appropriate and applied to ~R38 and a solar reflective roof is applied would that introduce any unforseen issues?
Thanks for any and all advice
Replies
In theory you should close the vents and create a "hot roof".
I'm with Dan on this one. Block the vents. Before re-roofing I'd open the roof deck from above and fill the whole thing with insulation.
Agreed. You have an opportunity here to insulate. Take it.