RetroFoam is a white non-expanding injection pressurized foam predominantly used in walls and sometime garage ceilings and slope ceilings of existing homes and most often for existing wall cavities of older homes. RetroFoam can also be installed even in newer homes that have fiberglass insulation. For example. homes where the home owner has little or no wall insulation and does not want the cost of removing and replacing drywall or plaster. RetroFoam is a white foam that looks and feels like Barbasol shaving cream when it goes into the wall. Within seconds, RetroFoam begins curing and is a dry powdery looking foam you can easily break with your fingers. It is like angle food cake or the light green foam the florist often use to stick flowers in. We often refer to it as a cereal box foam…it needs four walls, a bottom and a top so we can pressurize the wall cavity about 95% full. You get an R16 or R 18 value depending on stud size.

Sometimes, under certain circumstances, it can be injected into a flat or vaulted ceiling cavity or other unique places where there is limited space to fill and it can be contained.


SprayFoam comes in two types…Closed Cell and Open Cell, both must be either in a non-living space area or it must be covered with minimum 1/2 inch sheetrock or drywall. Interior spaces must have a 1 hour fire rating building material covering sprayfoam.

We use Closed Cell 2lb foam on the following:

  • Foundation walls about 2 inch thick or R13
  • Exterior walls where the wall covering has been removed for renovation, 2” R13 to 3” R19 thick and then covered with drywall or plaster or wood interior
  • Framing Rim Joist or Outer House band 3 to 4 inches and left exposed
  • Metal roofs underside and most buyers paint it later to protect it
  • Metal Buildings or storage shed walls and ceiling, various depths.  and most buyers paint it later to protect it
  • Home roofs underside (with a 6/12 or higher roof pitch) that may have week framing and home owner is not concerned with shingle warranty, 2 to 3 inches

We used Open Cell .5 lb foam on the following:

  • Crawl space on underside of house subflooring 5 inches R19
  • House shingle roof underside 5 inches R19 or 10 inches R38
  • Attic space (with a 6/12 or higher roof pitch) on roof deck or house ceiling drywall where fiberglass insulation has been removed. We normally spray  5 inches R19 or sometimes 10 inches R38 depending on rafter framing lumber size.

Blow in loose fiberglass

Blow in loose fiberglass is still a viable option when a home owner wishes to increase the R value of existing attic insulation. We always suggest the home owner tidy up any open electrical junctions and clean out attic prior blowing in additional loose fill fiberglass. We usually suggest an additional 8 to 10 inches.