- Q.We are remodeling a basement
apartment and want to lay a wide plank floor on
sleepers over a slab. What is the best way to insulate
the floor? Should we install a vapor barrier? If so,
where?
A.If the slab is
well-insulated along the perimeter, no further
insulation should be needed. Otherwise, any
insulation between the sleepers will do. If your
sleepers aren’t very deep, you may want to
use rigid foam insulation to get the most R-value.
The insulation should be installed around the
perimeter of the room at least 2-feet in from the
outside walls. It should not be necessary in the
middle of the floor. A vapor retarder should be
installed beneath the floor. The easiest way to
install it is to lay a sheet of polyethylene over
the sleepers before installing the
subfloor.