With the hot water heater question sorted, I need to get the area of the basement that the water heater and boiler are going into ready. Eventually this will be the mechanical room… when we frame out the basement, after we lower the basement floor, after we finish the rest of the house. We already ran gas line, but there are still a few things to be done.
Mechanical room wall
The boiler will be hung on the wall, and since the basement isn’t framed out that means it’s going on an outside wall. We don’t want to mount it directly on the brick because we want our house insulated and air sealed. That means we need to frame the outside wall where the boiler and panel will go. However, because we’re going to eventually lower the basement floor, we can’t just put a sill plate of the wall on the floor, we need to attach the studs to the brick wall. To ensure air and moisture management, we’ll use sill gasket behind the studs and fill the holes with caulk. The area between the studs we’ll fill with closed-cell spray foam.
Before any of that can happen, I need to prepare the wall. As is typical of our house, years ago someone saw a problem and went out about fixing it the wrong way. In this case, moisture problems with the brick foundation wall were not corrected by fixing gutters, redirecting storm water, or repointing the brick, they were “fixed” by slathering (parging) mortar or cement all over the brick wall on both sides in an effort to water seal it. This is generally a terrible idea because it traps water in the brick, rotting it from within. The ineffectiveness of this strategy is revealed by the coat of paint they put over the finished product which is now bubbled up and crumbling off.
So I’ve been removing the parging with my rotary hammer in chisel mode and a pry bar. It doesn’t need to be perfect, but the wall does need to be plumb. While the brick itself is pretty straight, the parging is thick enough in places to make for a wonky wall. Removing it is tricky because the parging doesn’t want to come off and it’s easy to damage the brick itself.
I also need to run electrical from the panel to the mechanical room. Chicago code requires EMT conduit, and in this case it’ll be ¾” because I need to run several circuits (lighting, hot water heater, boiler and pump, smoke detector, and eventually the air handler and HRV). I’m hoping to get both the wall prep and the electrical done by this Monday. With that out of the way we can get the hot water heater installed and focus on the remaining tasks for the boiler prep.
