Every building has its own vapor barrier requirements. If you want to know, does your house need vapor barrier, and what kind of barrier must be used, you should take into account climate zone, usage of building, and the type of house assembly. By the several code requirements, if you use closed-cell foam, vapor barrier is not necessary. But if foam is open-cell, that barrier must be applied. Scientists still discuss if those methods are efficient. Many of them don’t agree that vapor barriers are so necessary even with open-cell foam insulation.

There are three classes of vapor barriers. For example, closed-cell foam is from Class II and open-cell is from Class III. Also U.S. map is divided into 7 climate zones, every of which has its own requirements to the barrier class. For example, if your house is located in climate zone 5, you should use vapor barriers of class III.People who don’t know the exact requirements sometimes use double vapor barriers. But it may cause dew point occurring and unusual temperature changing, so it’s not recommended.It’s hard to say, does your building need vapor barrier or not. It depends on typical weather, climate zone, and usage of this building. If you have more questions about using spray foam insulation, please contact as and you will know the answers.

It’s hard to say, does your building need vapor barrier or not. It depends on typical weather, climate zone, and usage of this building. If you have more questions about using spray foam insulation, please contact as and you will know the answers.