from Richard in Eau Claire, WI:
#347
I am building a workshop with a loft on top for storage. To utilize it for storage we used 8 inch rafters instead of trusses. I would like to insulate and close in the ceiling and want proper ventilation and to protect the shingles from heat build up. Would you recommend a soffit ridge vent system used in vaulted ceilings? Any other suggestions?
Your solution is a good start.
You are correct to design a ventilation system consisting of soffit and ridge vents. Typically, a 1” – 1½” airspace under the roof deck is adequate. Consider using an insulation material that reduces air movement within the insulation (i.e. dense-packed cellulose or a blown-in fiberglass product) rather than using fiberglass batts.
An alternative approach would be to utilize an unvented system using closed-cell spray polyurethane foam. Building Science Corporation has an article that describes that approach (for any climate).
Published Friday, July 31, 2009