Venting Metal Roof Over Shingles

Ventilation basics roof ventilation depends on the simple scientific.

Venting metal roof over shingles.

Put the steel down directly on a vapor barrier. Lay the starter row of metal shingles at the drip edge and affix to the roof with metal roofing nails. It doesn t matter if the air space is a half inch or six inches because the condensation factor will remain the same. Work up from the initial row starting at the lower corner in a diagonal pattern staggering the shingles to prevent gaps.

Metal roof over shingles condensation metal roofs must be laid flat on a vapor barrier because steel will condensate if there s any air space underneath it. Cool outside air then travels under the shingles to the vented ridge detail 2 pulling out moisture and heat. Pros and cons for metal roofing installation. To vent the roof holes are cut in the old roof above the soffit which pulls air through the soffit vents underneath.

A metal roof typically does not increase nor decrease the need for ventilation. A steel roof is a lifetime investment lasting 50 years or more if it s a good one. To vent the roof holes are cut in the old roof detail 1 above the soffit which pulls air through the soffit vents underneath. Venting the ridge cool outside air travels under the shingles to the vented ridge pulling out moisture and heat.

Ventilation that meets code requirements is adequate for any type of roofing material including metal.