How to Insulate the Walls of an Existing Brick Home

Brick is an attractive and durable exterior finish for homes, but most existing brick homes are not insulated well enough. The method of construction of a modern brick wall requires the brick be fastened to a stud or concrete masonry unit wall, often without an insulative barrier between the brick and structural wall. Rolled insulation or cavity-fill insulation will provide a better barrier between the interior and exterior of the home.

Things You'll Need

• Cavity-fill insulation
• Blower
• Crowbar
• Reciprocating saw
• Tape measure
• Hammer
• Screw gun
• Rolled fiberglass insulation
• Utility knife
• Staple gun

Instructions

Brick Veneer Air Gap

1. With a crowbar or reciprocating saw, remove the roof soffit and framing above the brick veneer wall to be filled with insulation. The brick, structural wall and the interstitial air gap should be exposed.

2. The air gap is approximately 1.5 to 2 inches. Multiply the air gap dimension by the height of the wall; this is the volume of fill insulation to be purchased. Be sure to purchase insulation appropriate for exterior application.

3. With the blower, blow the cavity-fill insulation into the air gap until it is full.

4. Repair and replace the roof soffit and framing.

Interior Wall Rolled Insulation

1. Remove the interior wall surface.

2. Measure the width and height of the gaps between the wood studs. With a utility knife, cut the rolled insulation to fit between the studs.

3. Consult the manufacturer's instructions for installation, then fasten the rolled insulation to the wood studs with a staple gun.

4. Replace the interior wall.

Tips & Warnings

• The air gap in exterior walls allows moisture within the walls to weep through holes interspersed in the wall. Placing cavity-fill insulation into the air gap will hinder the walls from weeping the moisture. This moisture can collect within the walls, lowering the insulating qualities of the cavity-fill insulation and possibly allowing mold to grow within the air gaps. The use of cavity-fill insulation is not suggested for areas with high humidity.

References

• Foam of Akron: Insulation That Pays You Back

Resources

• Low Energy House: Retro Cavity Fill