Recently we completed a bathroom renovation on an old farm house, when the old bathroom had been completely stripped we discovered that the farmhouse was built out of double brick.
What is double brick? Double brick is a way homes were constructed a century ago before the invention of conventional insulation. Instead of building a stud wall and then bricking a single row of brick on the outside the house, the home was built by bricking the outside walls first and to make the brick strong enough they would built the brick in multiple layers giving it strength and making the brick wall thicker.
The lath and plaster was then installed on the inside of the brick, there was usually barn board or strips of wood that were used to build the brick outside walls left on the wall to give something to attach the lath and plaster too. The multiple layers of brick acted as a natural wind break for the cold winter winds, it also acted like an oven, when the home was heated from the inside it would reflect the heat back in making the heating the home a lot easier then other homes built at the same time.
The big problem once you have discovered that the home is double brick is how or if you will try to insulate the walls. Depending on the finishes, the window build outs and the amount of room you have it can be tricky to accomplish this without causing a lot of headaches and work for yourself.
With the bathroom renovation what we choose to do is to add SM sheets of foam on attached directly to the inside of the walls, affixing them to the existing barn board. The depth of the insulation would be determined by how much it would affect the overall inside dimensions. We settled on 1 inch of foam. Even through 1" of foam is not a tremendous amount of insulation it works quiet well when combined with the double brick. It is also a fairly inexpensive way to insulate a wall without losing a lot of space in a room like an old bathroom that is already short on space.
When working on old homes you have to be creative, not everything is simple or easy.
Village Builders Inc.