Polyurethane Foam Insulation Vapor Barrier

4 pitfalls of spray foam insulation.

Polyurethane foam insulation vapor barrier.

Assembly has been. However an installation between the studs can pose a challenge. Must be protected by an ignition barrier or if the. 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.

There are also vapor permeable air barriers and there are water resistive barriers that aren t air barriers. At a typical thickness of 5 open cell foam is rated from 5 to 10 perms. The 1 question to ask before putting spray foam in your attic. Closed cell foam is a vapor barrier closed cell foam has a much higher r value than open cell foam about r 6 5 per inch and it s a vapor barrier as well as an air barrier.

Download thermal and ignition barriers for the spf industry pdf from the spray polyurethane foam alliance. Dc315 fireproof paint is a fully tested and approved intumescent coating to meet 15 minute thermal barrier and ignition barrier protection over spray polyurethane foam spf. Dc315 meets ibc irc codes in the usa canadian nbcc and many international building code requirements. In all cases a functional air barrier system was provided in the form of sealed drywall or a continuous chain of spf and wood as this is required.

This document explains thermal and ignition barriers in more detail and gives the code references and testing requirements. However leakage can occur where the facings meet. As mentioned earlier batt and roll insulation come with a vapor barrier attached. These advantages include high insulation values near zero air permeability increased building strength severe weather and flood resistance increased occupant comfort.

Rigid foam insulation is usually a qualified vapor barrier. However an installation between the studs can pose a challenge. One manufacturer demilec says its heatlok high lift spray foam has an even higher r value r 7 5 per in closed cell foam is much denser about 2 lb. The research reported here investigated the ability of typical framed walls using spray polyurethane foam insulation with and without additional vapor barrier layers to meet these requirements.

Spray polyurethane foam insulation spf is a relatively new product to the residential building. For more information on this topic building science press published a research report in 2009 on the need for a vapor barrier in above grade walls with spray polyurethane foam which is located. A vapor barrier is designed to keep moisture in your home from getting inside your walls.