Installing Foam Board Insulation on an Exterior Wall

It is recommended that you install foam board insulation for exterior walls of concrete, foundations, concrete slabs, basement walls and crawl spaces. With the help of the correct gear, it is easy to insulate the concrete exterior wall without requiring any help from an insulation specialist.

Step 1 - Prepare the Wall

Before you begin, wash the wall with water and a mild soap. If you see any cracks, fill them with a repair substance.

Step 2 - Measure

Calculate the size of the area in which the foam board insulation is to be installed. Use your numbers to determine how much foam board insulation you need. Use marker or pencil for marking the area where you will make cuts. In order to mark longer lines, it is easy to use chalk. Now, use a hand saw or alternatively a reciprocating one to slash the foam board insulation.

Step 3 - Waterproof

In some cases, such as in exterior foundations, it is necessary to waterproof the wall before moving further. Once the waterproofing has dried out, you can install the insulation. Use quality glue, and spread it only to a smaller area so that it does not dry out before you finish the complete wall.

Step 4 - Mark Walls

The next step is to place the foam boards on the adhesive and set it into place. Mark lines at every 2 feet along the length of the wall using tape. Now after this, mark vertical lines 2 feet apart along the height of the wall. This gives 2x2 feet square markings on the wall. You will use the self-tapping concrete screws along with the washers to firm the foam in its place.

Step 5 - Spread the Screws

Distribute the concrete screws 2 feet apart horizontally and vertically across the total length of the wall. Ensure that washers and screws are protected from rudiments by applying fiber glass tape on top of them. If there is any bare foam board insulation on the exterior wall, it needs to be enclosed with cement board, stucco or metal.

Step 6 - Use Furring

It is necessary to install furring strips horizontally after every 2 feet. The next step is to cut the foam board insulation so that it will fit into the furring strips. In the absence of furring it will be advisable to cut and place the foam board as specified in step 2. The use of furring however is more for the interior walls.