Every building has its own vapor barrier requirements.
Does spray foam insulation work as a vapor barrier.
The short answer is yes as long as you have the right type of polyurethane spray foam and any approval that may be necessary from building inspectors.
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.
When professionally installed spray foam spray polyurethane foam serves as a vapour barrier.
However an installation between the studs can pose a challenge.
After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.
Foam insulation as an air sealing material one of the key differentiators between traditional insulation materials and spray foam insulation is the latter s ability to insulate and air seal.
The vapor permeability of open cell spray foam means that it can take in water and hold it which can be a real danger.
If you put spray foam insulation in a building it needs a thermal barrier.
If there s a fire in the building a thermal barrier keeps the combustible spray foam from the flames to increase fire resistance.
Open cell foam is also vapor permeable which means it does not count as a vapor barrier and needs to have one applied over it.
However while using spray foam as a vapor.
However an installation between the studs can pose a challenge.
Rigid foam insulation is usually a qualified vapor barrier.
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.
Not every wall does.
The application satisfies all the pre requisites for a vapour barrier as specified by the majority of building codes.
Properly installed spray foam insulation should act as a more than adequate vapor barrier.
That s what separates it from the occupied spaces.
To complete the vapor barrier you would want to foam seal or tape all the sides where the rigid meets timber because these gaps will facilitate vapor flow.
Dear pole barn guru.
Do i need to use a vapor barrier with spray foam.