Published on August 16th, 2017 | by Henri0
Venting for a summer camp roof
Q. We are replacing the steel roof on our summer camp, used May to September. The camp is uninsulated.
Twenty five years ago when we last re-roofed we had placed furring strips on top of the roof plywood and polystyrene between the furring strips. This made the cabin cooler in the summer. We plan on putting in a ridge vent this time. Would that make the polystyrene unnecessary? Thank you.
A. Are you planning to reroof with metal again? If so, installing a ridge vent may be a challenge because of the ribbing on screw-on metal roofing or the seams on standing seam roofing. It can be done, but it is tricky unless you contract with an experienced standing seam contractor that has developed a ridge vent system.
If the strapping for the existing metal roof was installed from rake to rake, as it should be, the ridge vent will not be effective. For it to work, it needs to have equal net free ventilation area at the soffits and a clear space between the soffit and ridge vents. This will require a set of strapping installed from eaves to ridge and another set from rake to rake for screwed-on roofing, or a new plywood deck if you choose a standing seam roof.
You certainly can keep the rigid insulation, as the new venting system is unlikely to be as effective.