The mudsill is the bridge between your home’s concrete foundation and its entire wooden frame. These crucial, pressure-treated boards are the very first pieces of the structure to be installed, bolted directly to the foundation. They have to be right, because everything else builds on top of them.
The first step is always to double check the foundation for size, squareness, and level. Repairing an out of whack foundation is much easier without a whole house sitting on it. This is true whether you are a novice building your own house or if you are a professional framing contractor with many years experience.
Once you are satisfied with the foundation, you can then clean it. There may be little specks of concrete or mortar that need chipping away so the treated boards can fit flat against the top of the foundation.
The treated boards are typically the same width as the foundation wall. 2 x 8 is standard to cover an 8″ block wall. The board must cover the majority of the wall in this case.
The foundation and its anchor bolts also has a story to tell you if you are listening. The building codes for the anchor bolts are simple. No more than 6′ apart and no more than 1′ from the end of the board. Ther foundation contractor will most likely have the bolts layed out for 14′ material to work. That is 3 bolts per 14′ board when done properly. The trick is to start on the right end.
Whether you need to follow a chalked line or the edge of the wall, a speed square is indespensable. The trick to it is to “hook” the center of the anchor bolt and measure out to the line.
It is important to note that every mud sill has a gasket. This is a thin layer of poly or foam that is a barrier between the wood and concrete. It is very difficult to install if you have to come back later so don’t forget it.