Over the past few years, we have
both had the opportunity to try
Sparfil Block—the heavily insulated
concrete block developed in Canada.
Unlike other insulated block systems,
Sparfil does not achieve its outstanding
R-value simply by using foam
inserts in a modified block. Foam
inserts improve the R-value of block
foundations, but the effectiveness of
this approach is usually limited by two
factors. One is that there is only so
much of the block that can be
removed to make room for the insulation
before the block becomes too
weak and fragile. The remaining block
presents a significant thermal break.
The second limitation is the mortar
joints. Even if the R-value of the
blocks is raised, the 3/8-inch mortar
line