How to Insulate Concrete Walls

What You'll Need
A drill and masonry bit
Specialist wall fitting plugs
Work gloves
Utility knife
Measuring tape
Marking pencil
Safety glasses
Hand or table saw
2x4 timber
R-13 batt insulation
Staple gun and staples
Dust mask

Learning how to insulate concrete walls is a task suitable for the intermediate enthusiast. This guide will show you how to insulate concrete walls in any room of your home. 

A few simple tools are required. Be sure to wear gloves and protective clothing as well as a dust mask for your own protection. 


Step 1 – Prepare the Room

Remove moldings from around the floor and ceiling if necessary. Make sure that everything is removed from the walls before work begins. If necessary, remove flooring and carpets, and close down the electrical supply to the room for safety purposes. Loosen electrical fittings—you can replace them later.

Step 2 – Build 2x4 Frames 

A frame must be built for each section of wall in the room you are working in. This will provide a recessed area for the insulation to sit in and can be made using 2x4 timber. 

Frames should be built as 4-sided pieces. These can be made on the floor and lifted into place when finished. 

Measure the first wall and build the frame by nailing the top, bottom and two sides together. After completing one frame, you will need to measure the next concrete wall before continuing. Be sure your measurements are precise so that everything fits into place.

Some additional 2x4 timber can now be used to make the inner placements and these should be sized up and nailed into place. Place these in pairs around 16 to 24 inches off-center to provide support for the outer frames.

For heavier wall materials, use extra lengths of timber and place them apart in 16 inch intervals for additional strength. Be sure to allow for any outlets, switch plates and electrical boxes so that the wood is not in the way. 

Step 3 – Install the Frames 

Install the frames to the concrete wall by fixing them in place. A masonry drill will be required to make holes in the concrete and the frames can be attached using specialist wall fitting plugs and some screws. 

Be liberal with attachment points to ensure that the outer wall stays in place after installing it. 

Check the finished frames thoroughly to make sure they are safely fastened to the wall so that they hold up when the outer panels are ready to be installed. 

Step 4 – Adding Insulation 

Measure the frame opening and cut the insulation to size from the paper side using the utility knife. Staple the insulation in place with the paper facing the room you are working in. The insulation can be attached to the frames using the extensions that are usually provided on the batting. 

Be sure to fill in all sections so there are no gaps. Cut out areas for switch plates, outlets and protrusions such as electrical boxes. 

Do not compress the insulation behind piping or other protrusions. Instead, slice the insulation with your utility knife in a manner that allows you to have insulation behind and in front of the pipe. 

In order to cover insulated concrete walls from the inside of the home, add sheet rock, paneling or another suitable medium so that the batt is completely covered.