Venting Metal Roof Over Shingles

This is what it looks like when you install a steel shingle roof system over an existing asphalt shingle roof.

Venting metal roof over shingles.

Ventilation that meets code requirements is adequate for any type of roofing material including metal. Before you reshingle a roof read our step by step guide for adding new shingles over old ones. After all you ll be making a significant and long term investment. A steel roof is a lifetime investment lasting 50 years or more if it s a good one.

Metal roofs must be laid flat on a vapor barrier because steel will condensate if there s any air space underneath it. A metal roof typically does not increase nor decrease the need for ventilation. Metal roof over shingles condensation. If it s slightly windy keep the steel downwind from you so a gust of wind doesn t knock you over.

The frame creates a ventilation gap that helps prevent ice dams in the winter and cools the roof and the house in the summer. Doesn t provide the flattest surface for the metal roofing to be installed over each course of shingles is about a 1 8 higher than the course just below it. Cool outside air travels under the shingles to the vented ridge pulling out moisture and heat. 3 install 1 4 purlins down over the shingles before installing the metal roof the third way to install a metal roof over shingles is by applying 1 4 purlins over the shingle roof.

One of the big reasons homeowners choose metal roofing is for the uninterrupted run of metal from the top of the roof to the gutter which reduces the risk of leaks. When installed as part of a properly balanced when installed as part of a properly balanced attic ventilation system gaf cobra exhaust vent is a shingle over exhaust vent installed at the roof ridge that helps exhaust excess heat and moisture from your attic. Also don t go up on the roof if it s windy. Venting the eaves to vent the roof holes are cut in the old roof above the soffit which pulls air through the soffit vents underneath.

Beveled wood pieces called horsefeathers must be laid along the thick edges of the shakes to make a fairly flat surface. Asphalt shingles can be laid over cedar shakes or shingles however this is a roofing project best left to pros. We do need to mention though one very rare scenario we have seen just a couple of times over our 35 years. If you are trying to decide between the two materials it s important to carefully look at the metal over shingle roof problems.

Installing metal roofing over shingles can help solve these issues.