As the federal energy star program and international energy conservation code continue to push the envelope for effectively insulating exterior walls against thermal loss to boost a home s energy efficiency builders of block walls are being forced to adjust their practices to comply with the more stringent standards.
How to insulate exterior concrete block walls.
In some cases the joints between boards are set into an expandable bead of sealant or caulked or taped to act as an air barrier.
That s because in the past insulating concrete block homes meant adding interior wall insulation by building another wall against the concrete and insulating between the studs.
The board insulation may be attached with an adhesive or mechanical fasteners.
Spray foam insulation for concrete block walls.
This is recommended so when the concrete walls are sprayed the foam insulation can get behind the stud to prevent any thermal bridging.
For decades the best way to insulate concrete block was on the interior of the wall which required framing another wall up against the concrete and insulating between the studs.
But since the below grade interior also has to be insulated to a continuous r15 it s probably easier to do the bulk of the insulation on the interior then install rigid rock wool on the exterior sufficient to bring the u factor under the code max u 0 045 r22 whole wall including the r values of the siding interior finish materials the.
Leave the floor above it uninsulated vapor seal the ground below with polyethylene and a thin concrete slab insulate the walls with a foam based insulation such as 4 in.
Today there is no need to lose out on valuable interior space as you can use external wall insulation to insulate your concrete block house.
Tight joints between the insulation boards maximize the thermal performance and reduce air leakage.
Spray foam insulation works for insulating concrete block walls before the drywall has been put into place and the studs have been furred out about a quarter of an inch to a half inch.
The simplest and most affordable method of insulating the interior of a block wall is to install rigid foam board insulation.
Available in large three by five or four by eight sizes the panels.