Below Grade Foundation

Medium density spray foam insulation can be used to insulate basement walls on the inside or outside after construction, and low density spray foam insulation can be used to insulate the inside of basement walls.
In many situations insulating with can outperform foam board and other insulation types as it is less likely to be damaged during construction or by moisture after construction.

 

Common Problems with Basement Wall Insulation on the Interior Side

Below-grade foundation walls are sometimes insulated on the inside with either rock wool or foam board – here are some issues resulting from using those insulation types:

  • Edges and penetrations are difficult time-consuming to insulate, and subject to human error.
  • Insulation can be damaged by water or other moisture, which may compromise its performance.
  • Insulation may be a source of food for mold, which can spread and damage finishes.
  • Insulation may be damaged by pests.

Common Problems with Basement Wall Insulation on the Exterior Side

Below-grade foundation walls are sometimes insulated on the outside with foam board – here are some issues resulting from using that insulation types:

  • Edges and penetrations are difficult and time-consuming to insulate, and subject to human error.
  • Insulation may be displaced or damaged during backfilling.
  • Insulation may be damaged by termites or other pests.

Benefits of Spray Foam for Basement Insulation

  • Improved indoor air quality (IAQ).
  • Easily insulates edges and penetrations – expands to fill holes.
  • Foam rejects bulk water, has <5% water absorption.
  • Holds its strength when exposed to water.
  • Not easily damaged.
  • Not a source of food for mold or pests.