Hi, it’s Rick, from Bay Area Mold Pros this week. We’re going to take a look at some footage that I shot at a few different homes here in the bay area. And all of these homes have something in common. They’ve got retaining walls, holding back a lot of soil. They were all built on hillsides. When you have this condition, you’ve got moisture.
That’s going to make its way through these retaining walls. Into the space inside the home. Most of these homes, when they were built, this space was not intended as living space. It was extra space. It was under the home, it was storage space, but because of the high cost of real estate here in the bay area, this space is all now being recaptured and turned into living space and it’s creating a lot of problems.
So the moisture’s coming through the retaining wall. Because no, no waterproofing measures were taken at the time of construction. We would do that now. And the second thing is this space is built on a concrete slab and we have the same problem. When we pour slabs today, we put down gravel breaks, we put down waterproofing, and then we pour the concrete in decades past, they didn’t do this.
So we’ve got moisture coming up through the concrete slab. We’ve got moisture coming through the concrete. All of this moisture is resulting in a lot of mold. We’ve got a bedroom here, which is below grade, the small window that appears in the, uh, the upper portion of the wall here is on a kind of a tradesman’s entrance.
It’s got a concrete cover, but you can see the foundation covered here. And that’s pretty much below grade. As we go back into the closet, the tenants have noticed what they think is mold on some personal property and you can see the exposed foundation.
And we’re definitely below grade here, humidity in here measured in the mid 60 range up about 66. There is a small deal dehumidifier running in this space. But we probably need to increase the size of the dehumidifier. So this is outside the footage we just had of the apartment below grade. We’re looking at the great out here covered with concrete, but the apartment itself is several feet below the grade level here.
So we’re getting water from the side of the home, the high side, making its way into the basement apartment. Where we were just standing. You can see the window at the far end of this wall, and that’s the window that we could see in the bedroom wall, above the foundation, which was boxed in we’re up on Telegraph hill in San Francisco.
This is a, an old apartment house on the hill here. And the second window we’re looking at is the bedroom window. And you can see that this room is below. You can see the great out here with the concrete on the walkway and you get a drop down about three feet to get down to what would be the floor level inside this wall.
So in terms of, uh, what’s behind here, what was done, whether there’s a bunch of soil up against this concrete foundation wall, I’m assuming there is, and this concrete was poured onto. We’re looking at the side of a home in Belmont. This is a 1930s vintage home and where we’re standing, we’re essentially below grade.
You can see the grade at the front yard and it’s that the top of these three steps. So everything below that is below grade in terms of. Ground floor of this home. There are some water intrusion issues, and eventually there’s going to need to be a French drain installed along the front of the home and the side of the home to ensure that no more water gets into this living space.
Hey, it’s Ray conveyor and malt pros. We’re standing in the ground floor space of an old home in Belmont. This space originally was not intended as living. But because land is of course so valuable in the bay area, it was eventually developed. This is the front of that home out here and everything around us is below grade.
So we’ve got some moisture intrusion issues over here on this wall. This is the sidewall of the home. You can see the foundation is stepping down here. Eventually the owners are going to put a French drain out. Eventually, there’s going to be some waterproofing for the slab on which we’re standing. And until you do that, you’re going to continue to have moisture that comes into this space.
Again, for the simple reason we are below grade. So the front foundation wall of this home is holding back tons of dirt and that dirt is saturated with water. We’re looking at the side of a home. This is a 1930s vintage home in San Carlos. And as you look at this window on the left-hand side, the left corner of it, the left bottom corner is about one foot above grade on the exterior.
So you can see this foundation wall and the foundation wall was covered with a cinder block wall. The rest of the foundation wall has been covered with plywood there’s space behind it. And you can see the plywood stepping down and the foundation does the exact same thing. It steps down on the outside of this wall.
There has been water that has made its way through this wall over the years. And the client is looking at putting in a French drain to alleviate that issue. We’ve also got an original slab here. This goes back to the 1930. And there’s a lot of moisture, which is making its way through this concrete slab.
And so the client has, uh, decided to put into poxy coating on the other portion of this slab, which is exposed. And this area in here is going to get some other kinds of flooring cover.
If you have any of these conditions within your home, the badness. It’s pretty expensive to take care of the construction fixes. They may involve pulling the soil back and putting in waterproofing against your foundation. They may involve the use of French drains, some pumps in terms of slabs that are already in place.
You can apply a poxy finishes to the top of them. But the best thing to do is to actually pour a new slab and port with modern waterproofing techniques. If you’re not going to do these things, there are some short-term interim fixes that are going to help you with the formation of mold in these spaces.
Number one, run dehumidifiers. You’re going to be amazed at how much water dehumidifiers pull out of these living spaces, because there’s so much moisture coming in. Number two, don’t store things up against the concrete foundation. Pull things away from the walls and allow them to breathe. Number three, run a lot of fans.
That’s going to help with the airflow and that’s going to help to cut down on the condensation on these walls, which is going to cut down on the formation of mold. So those are the things you can do short of the really expensive long-term solutions because.