Veneer
If solid masonry is so good, why is it that most brick houses built in the last 30 years are brick veneer construction? Firstly, we have to understand the difference between the brick veneer and solid masonry. The biggest difference is that with solid masonry, the brick is holding up the house. With a brick veneer, the house is holding up the brick!
When we say brick veneer, we don’t mean those little thin slices that you glue on your kitchen wall. We mean an honest to goodness brick. However, the wall is only one wythe thick. Behind the brick veneer is a wood frame wall that is actually holding up the house. The brick veneer is, in effect, siding!
Insulation
Brick veneer became the norm when building codes began to require insulation in the exterior walls. One of the best insulators is air. Most good insulation does nothing but trap air; that’s why most insulations are light and fluffy. Brick is not exactly light and fluffy. Therefore it’s not really a very good insulator.
A brick veneer house is really a wood frame house where the cavity between the studs in the wall can be insulated. The walls are built, covered with sheathing, and often insulated before the brick is even installed. As the brick is being installed, metal ties are nailed onto the wood frame wall. They must be nailed into the studs and not just into the sheathing.
The metal ties are then bent so that they are horizontal where they become embedded in the mortar joints as the brick veneer wall is constructed. The brick veneer is built on the outer edge of the foundation wall so that a one-inch air space remains between the brick veneer and the sheathing.