Hi, it’s Rick of bay area mold pros. We’re going to take a look at three properties that I’ve taken some video of the first tour in San Francisco. And the last one is in the open Hills in the first property. It’s an old apartment house, 1920s era, very high humidity. It was in the seventies. The humidity is exacerbated.
The fact that there’s no air flow. So we’re getting condensation on the walls. It’s leading to mall. So we’re looking at a 1920s era apartment house in his valley, and we’ve got visible mold on the interior of what should be a solid concrete wall. And I believe we’re looking at the. The original campus in the second property.
What was most interesting is that this is new construction. This is a fairly new apartment house in San Francisco, and it’s got an exterior concrete wall. We know that those are problematic. They’re called in the outside, warm on the inside. They lead to condensation, leads to mold again. What was interesting about this?
Is that it was fairly new construction, the humidity in the bedroom where I found this mold, it was up in the seventies. Very odd. We’ve got a combination of problems going on here. There’s no airflow in here. We’ve got a cold concrete surface and we’ve got tenants who are leaving the windows closed here.
The humidity measured 72 in this room, which is exceedingly high. So I think you can see the mold here. I’m going to try to wipe it down just to demonstrate out, just kind of floating on the surface. You can see what happens. Green mold is just sitting on the surface of the concrete. The concrete is actually wet to the touch.
It’s so moist and it’s so humid in this apartment that this mold is just kind of floating on the wall. The last property we’re actually standing in the crawl space, very high humidity down there. The soil is exposed for on a hillside. The naturally occurring groundwater makes itself up its way up into the air.
And that vapor eventually makes its way up into the. What was unique about this case is that the homeowners had put in a ventilation fan and these fans are, are designed specifically to fit into the foundation vent openings in a home, very effective. It brought the humidity down into the 51. Which is acceptable.
We’re in a 1950s era home in the Oakland Hills, the hill is going this way. That’s the front of the home for years and years, these folks have been here for over 50 years. And for several decades, they had water coming into the crawl space in which we’re staying. And it ended up going into the room behind us concrete slab.
They eventually put in a French drain outside of this foundation wall. It took away most of the water, but we still have elevated humidity in here. And what they ended up doing is putting in crawlspace ventilator. It’s got a humidistat on it, so that it turns on when you hit a certain humidity. In this case, it’s set at 45 and the homeowners have said it never goes off.
So the humidity down here is high enough that this fan stays on 24 7. The lesson in all three of those videos is even though Roe was looking for the water, we’re looking for roof leaks, window leaks, door leaks, plumbing leaks. Sometimes there’s no legal. Simply the humidity. And if the humidity is high enough, you’re going to have the simplest thing to do.
If you’ve got these issues, bring in some machines, dehumidifiers are great for living space. These foundation vents. They’re great for crawl spaces. .