Chris Chu, AIA, Newton, MA, architect, This Old House

Insulated Concrete Forms

There will be four types of insulation going in this week at This Old House.  Generally, there will be open-cell spray foam insulation in the new walls except in the basement where the foundation had insulation integrated with the forms, called “ICF” or insulated concrete forms” (see photo below of concrete being pumped into the foundation forms … they had to go over the house because they didn’t have access to the backyard!)  So, actually there are five!

Chris Chu, Architect, Newton, MA, This Old House, ICF, concrete

Concrete being pumped into foundation wall

In the existing walls that were not opened up Tom and his subs will spray in cellulose.  The original house had a thin material that was maybe a half-inch thick that was not readily identifiable.  In the ceiling of the new sunroom, we have a special condition where the floor “sandwich” is rather shallow so a closed-cell insulation will be used there for its higher R-value (a standard for measuring thermal capacity – the higher the better).  Then, in the ceiling of the family room in the basement, regular fiberglass insulation, the pink stuff, will be used to keep the heat of the radiant flooring in the sun room above.

So that is five types!  There actually may be six if you include the rigid insulation that will be placed behind the “niche” that will be installed in the wall above the stove, for extra insulation.