No one can deny the beauty of a brick or stone house. These homes have an elegant look that is impossible to mimic with other materials. Unfortunately, these materials are also the worst for moisture penetration, air leaks, and general energy efficiency.
Brick and Stone Veneer Siding
Brick and stone siding is installed with a gap between the back of the brick and the wall as an area for water to escape. This is known as a weeping channel and is necessary to keep the brick from rotting as well as the house framing from rotting. The wall is covered with felt tar paper to protect the sheathing and the framing from moisture. Moisture penetrates the stone or brick through the mortar, which is not water proof by any stretch of the imagination. In fact, water will penetrate through brick or stone mortar in under 45 seconds in most cases. The biggest problem with these wall systems and that they leak water, but also air making them very inefficient.
Full Brick or Stone Walls
These walls are very thick and usually are not insulated at all. However, these are the most structurally sound of any of the older homes built and will probably out last many of the homes that are constructed, even today.
So how do you properly insulate your brick or stone home?
Insulate From the Inside
This is messy, but worth the energy savings. You need to drill in between every stud. If you can find all your studs on the exterior walls, you can drill holes on the edge of each stud so you only have one plaster/drywall patch per two stud bays. The holes need to be at least 1″ wide. You then fill the stud cavities with cellulose insulation which is packed into the cavity tightly filling every nook and cranny. This is the best insulation choice for performance of an existing wall system and the greenest solution available. This is also the messiest solution as every cavity needs to be filled and every exterior wall need to be down. An insulation job of this nature usually costs $1,000 to 3,000 for the insulation and the wall patching. Actual wall finishing and texturing will cost extra. If you are willing to do the work yourself, it will probably only cost you about $500.
Insulating From the Outside
To insulate from the outside, you simply need to install 2″ polyurethane or polystyrene foam board insulation. Then the outside of the foam board should be covered in EIFS (exterior insulation finish system). This product looks like stucco, but smoother and allows you to insulate your house properly while still having a beautiful exterior finish. This system is very expensive, but if you have all brick or stone walls, this is your only option. This system will probably save you up to 50% or more on your energy bills, but may still take 7-10 years to pay for itself. This is something you would need to have professionally performed as it takes a lot of skill to properly install this product.
Whether you insulate from the inside or outside, the process is not fun. However, if you are concerned about energy, these methods will save you big time.