Putting Up A Moisture Barrier Metal Roof

It s also a good idea to discuss the options with your roofing contractor because they will be able to check the type of shingles your roof has and advise on the suitability of leaving the shingles in place or removing them.

Putting up a moisture barrier metal roof.

Put the steel down directly on a vapor barrier. The problem with using. Whether or not you need a vapor retarder hinges on three main factors your climate your home and the location of the wall you re insulating. Metal roof over shingles condensation.

One common problem is moisture build up between two layers of roof type which must be avoided. 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. But a preinstalled membrane may be even more effective at removing condensation. When exposed to moisture metal components can oxidize and weaken decreasing the life of your customer s building.

Corrosion of metal components even on surface treated metal. Traditionally we ve insulated the roof panel to try and keep the temperature on the panel from reaching the dew point. 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 roofs must be laid flat on a vapor barrier because steel will condensate if there s any air space underneath it.

The problem with this is that as the metal heats up and expands or cools down and contracts it moves a little 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. To know if you need a vapor retarder ask yourself a few basic questions. Single bubble vapor barrier and 2.

We ll add a vapor barrier so the moist air does not flow up through the insulation and condense on the roof. In metal buildings there are a few possible consequences of trapped moisture in wall and roof systems. It blocks condensation from dripping into a pole barn and runs it out of the eaves as well as adding a slight r value to the roof and also.