How to Insulate Concrete Basement Walls

Insulation is vital for concrete basement walls. It is in basements that the house’s furnace, water heaters, laundry machines and essential utilities are commonly kept. Because they are naturally located below ground level, basements are mostly cool and damp. Basement walls made out of concrete, stone, concrete block and other masonry foundation materials have very minimal insulating properties and cause approximately 20% of heat loss in a home. This is why insulating your basements walls is necessary, especially when you live in areas that have very cold climate.

Step 1 - Assess the Situation

There are basically three ways of insulating basement walls, namely, from the outside, from the middle of the foundation itself and from the inside of the structure. Unless the house is still in the planning phase, insulating a basement from the inside is usually the most practical way to go.

The most common types of insulation are fiberglass batt insulation, foam insulation and blown-in insulation. These installation types have corresponding R-Values (thermal resistance). You must choose the type of insulation that is most practicable and applicable to you. There are also building requirements that you have to comply with like local fire codes and building codes. Most often, you will have to consult a local builder and check with local building authorities to make sure that your project will meet their requirements.

You also have to check for basement interior features that can make your insulation work more difficult such as uneven walls, cracks, leaks, dampness, or bulges. These should be resolved before insulation begins.

Although many interior insulation installations are easy to carry out, in some cases it advantageous to call a professional.

Step 2 - Determine the Best Insulation

Among the different types of insulation, fiberglass batt insulation is the easiest and cheapest. It is more efficient than foam insulation and not as messy as blown-in insulation.

Step 3 - Ensure Safety Precautions

Fiberglass insulation may irritate exposed skin areas so it is recommended to wear a long-sleeved shirt, long pants and light work gloves. A respirator mask and safety goggles would also be helpful.

Step 4 - Perform the Proper Insulation

Fill all voids. Place the insulation between studs, joists, and rafters, stapling them into place as you go. The most important thing in an insulating job is tight-fitting batts that completely fill the stud cavities with no voids or gaps. Remember to fit batts first before cutting them. When dealing with electrical cables and boxes, you have to split and cut batts to fit around them. Next, stuff scraps of insulation in any open areas where heat loss may occur. Be sure to fill all gaps in windows and doors. Finally, check all areas again to see if there are any more that need further insulation.