Metal Roof Installation Moisture Barrier

Several considerations must be addressed in the roofing system design including ensuring that the four barriers needed in any building enclosure i e water barrier thermal insulation barrier vapor retarder and air barrier are provided and are in the correct location for a given climate.

Metal roof installation moisture barrier.

Remove the old roofing. Benefits of metal panels for agricultural buildings. Metal roofs must be laid flat on a vapor barrier because steel will condensate if there s any air space underneath it. Selecting metal roofing trim.

If you choose to omit the plywood from a residential construction install a vapor barrier between the purlins and the metal roof or plan to spray closed cell foam insulation between the rafters to eliminate the temperature differential between the air in the building and the metal. Work at a comfortable steady pace trying not to rip up or carry off too much old roofing at once. We ll add a vapor barrier so the moist air does not flow up through the insulation and condense on the roof. It doesn t matter if the air space is a half inch or six inches because the condensation factor will remain the same.

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. Selecting applying metal roofing touch up paint. How to prepare for metal roof installation. Exceptions to this idea include roofs over indoor swimming pools or other high humidity producing activities and over new concrete roof decks to prevent the moisture in the concrete from drying into the roof system.

From what i ve read online it seems wise to install a vapor barrier over the plywood to prevent condensation from getting absorbed into the plywood from the steel roof. When we use a vapor retarder in a roof system it will also act as an air barrier as long as it is sealed at all perimeters and. Tips for installing metal roofing accessories. Although you can install corrugated metal roofing over shingles for the best foundation it is recommended that all the old roofing be removed.

As long as the plywood under the shingle roof is in good condition this way can provide many benefits. The problem with using. This is by far the most common way to install a metal roof.