Rigid Foam Insulation Interior Basement Walls

Eps is used under roofing over foundation walls and beneath siding.

Rigid foam insulation interior basement walls.

Use a premade kit for this type of project. For a basement remodeling project consider insulating basement walls with foam board. 15 19 means r 15 continuous insulation on the interior or exterior of the home or r 19 cavity insulation at the interior of the basement wall. This foam board insulation is the rigid pink or blue panels that can be found at home centers in many different thicknesses.

Martin my copy of 2012 irc says 15 19 for basement walls in zone 5. Rigid foam panels are also a good way to insulate on the inside of concrete basement walls. The correct method of using rigid foam is to run continuous 4 foot by 8 foot sheets of the foam across the concrete basement wall making the rigid foam the de facto wall. When insulating interior basement walls in a finished basement use our styrofoam brand insulation.

On the interior the best insulation to place against the concrete or block is rigid foam without any facing such as foil or plastic sheeting. 15 19 shall be permitted to be met with r 13 cavity insulation on the interior of the basement wall plus r 5 continuous insulation. Creates a finished appearance. Styrofoam brand insulation is a rigid insulation that can be placed directly on walls framing and drywall.

My basement has some old insulation above the frost line as well as some 2x4s nailed down to the concrete walls. The place to control vapor migration is on the exterior of the basement wall in the form of waterproofing or damproofing. It provides an r value of 4 per inch of thickness and is the cheapest type of foam board insulation. Rigid foam insulation on interior basement walls on september 23 2020 by amik unvented insulated crawles basement insulation building science insulated basement wall panels eps xps foam insulation styrofoam best methods for insulating basement walls.

For new construction use rigid boards to insulate slabs and the outside of foundation walls. Depending on thickness and the type of foam you choose super high effective r values can be achieved. After that thin furring strips are installed on top of the foam to provide a firm base for the drywall screws and drywall but can you run rigid foam between the studs just as you would do with fiberglass rolls or spray foam. A footnote explains this notation as follows.

The short answer is no you generally do not want a vapor barrier on the walls of a finished basement. Attach the tongue and groove insulation boards to the concrete wall with adhesive.