Open Cell Foam Insulation Moisture Problems

If closed cell is used the moisture cannot make its way to the wood and present.

Open cell foam insulation moisture problems.

Moisture generated indoors or that infiltrates into the home is responsible for the bulk of the moisture in an attic insulated with spray foam on the underside of the roof sheathing. It has a relatively high vapor permeance 3 perms at a thickness of 6 allowing water vapor to migrate to the roof decking at night and back into the attic air in the daytime. Sealection500 the open cell spray foam used at iowa spray foam only allows 0 001 l sm2 of air to pass through at 50ps. Thick applied beneath and spanning the floor joists held on with cap nails and seams taped edges sealed with a foam sealant is a tested good solution.

It s just a pathway. It s the wood decking that stores the moisture though. Oh and when you put it in your attic spray foam. Open cell spray foam insulation doesn t store the moisture.

Open cell spray foam will allow moisture to get to the metal surface. Remember that open cell spray foam is also an air barrier. Lstiburek takes blame for bad language. 50 pascals of air movement is equal to about 16 mph wind.

According to frank moisture can be a concern if you construct a home and insulate it with open cell spray foam. The spray foam insulation chemicals weren t mixed properly. Choose open cell spray foam when insulating roofs since closed cell foam can trap water from a leaking roof damaging the framing material and roof sheathing. Many homeowners love spray foam insulation and it s easy to understand why.

According to the epa spray foam insulation is one of the best insulation materials used to minimize moisture related problems that are caused by random air leakages that fill all the cracks and crevices where air can enter into the environment. It s not coming from above the roof and it s not some new moisture source resulting from the spray foam. It is lower cost than closed cell foam and has the plus of flexing with the building but can be tricky to get good paint skin coverage. For example icynene open cell spray foam must be installed at 3 inches before an air barrier is created.

Be sure to have that discussion with your licensed contractor and don t be afraid to double check the information before the project begins. Open cell s vapor permeability enhances an assembly s ability to dry out via diffusion should it become wet open cell spray foam may absorb moisture if subjected to hydrostatic pressure but will allow moisture to drain through open cell spray foam will not wick water or contribute to capillary action.