The concrete should be dry and free from cracks before installing foam insulation boards.
How to install rigid foam insulation on concrete walls.
The fit should be firm but not so firm that the edges of the foam begin to tear.
Lay a panel of polystyrene.
There s two ways you can go about with foam board insulation.
When the entire surface is covered with the panels measure vertically down one panel so that a mark is made every 24 inches.
At each mark make a horizontal line using a carpenter s level.
Firstly you can apply it directly onto the house s concrete walls with the help of a construction adhesive that will hold it in place.
Install the rigid foam insulation.
Against the concrete surface with the still wet glue place the insulation panels.
Tip 2 use the right tool for cutting.
Cut each sheet of rigid foam insulation to fit the crawl space wall height.
When applying rigid insulation of any type to concrete it s important to first apply some sort of sealant and protectant to the concrete first.
Secondly and this is the best way you can install a drywall to frame the wall before applying foam board insulation.
If this happens pull out the sheet and slightly trim down the edges with the saw.
If not then you run the risk of the concrete absorbing to much water through the foam and breaking down.
If necessary address moisture problems and seal cracks before you begin.