Insulating Concrete Walls Below Grade

Basement walls made out of concrete stone concrete bloc and other masonry foundation materials have very minimal insulating properties and cause approximately 20 of heat loss in a home.

Insulating concrete walls below grade.

Both above and below grade icf walls are durable sound reducing energy efficient and disaster resistant. However for masonry block walls and below grade insulated concrete forms the surfaces must first be prepared. A properly insulated basement provides comfort and is a good way to save on your energy bill. Because insulation installed on below grade building foundations and under concrete slabs is often exposed to moist soil it is crucial to choose an insulation that has minimal long term moisture retention and the ability to dry quickly.

Insulation is applied to houses with slab on grade foundations exactly as you would insulate the outside of a full basement see section 6 1 insulating the basement from the outside. Any of the following insulation materials are acceptable for this purpose. The best way to insulate the interior side of a basement wall is with foam insulation that is adhered to or sprayed directly on the concrete. Closed cell spray polyurethane foam or either xps eps or polyisocyanurate rigid foam.

For poured concrete walls a damp proof coating can be applied directly to the surface. The variety of concrete masonry wall constructions provides for a number of insulating strategies including. Interior insulation insulated cavities insulation inserts foamed in place insulation granular fills in block core spaces and exterior insulation systems. Because they are naturally located below ground level basements are mostly cool and damp.

Installing rigid foam insulation below grade on building foundations the insulation whether eps or xps is installed over the damp waterproofing after that layer has adequately cured. Wet insulation is ineffective insulation rigid foams that retain high volumes of moisture lose about half of their insulating r value. If the foundation is on frost susceptible soils install a layer of impermeable insulation horizontally in the soil at a slope ratio of 1 5 for at least 1 m 3 ft. Rigid foam can be adhered to a poured.

Basements however have specific features that must be kept in mind when it comes to insulating the foundation from the inside starting with the fact that a variable portion of the walls is below ground. Insulation on the exterior of below grade portions of the wall is. However because of soil conditions below grade walls require added waterproofing steps unlike above grade walls.