One of the questions we often ask is where the water gets into the crawl space. Water in your crawlspace most often comes from the outside of your home. It comes from rainwater that perks down into the ground, becoming groundwater. Most of the time, your crawl space is lower than the ground outside your home.
So that groundwater, as it makes its way downhill, hits the home’s foundation wall. Then it typically finds its way through the brick or the masonry products that build the foundation concrete block. However that’s built, it can seep in through the block. It can come down and seep between the footing and the foundation wall and sometimes find its way under the footing and back up into the crawl space. So one of the ways that we solve this problem is we install what we call a French drain.
A French drain is a simple method of drainage installation where plumbers come on the inside of the foundation wall and dig out an area next to the foundation wall and the footing. Then they install a section of four-inch perforated pipe. Perforated means that the pipe has holes so that when the water finds its way through the foundation wall, it picks up inside the pipe, and the pipe collects the water and takes it to a sump pump. That pump discharges the water from the home.
Sometimes, the water seems to be coming in under the footing and maybe a little further away from the foundation wall. Plumbers can adjust the location of that drain accordingly to pick up any water that comes through the foundation wall from the groundwater outside. So that’s the quick basics of a French drain, why it’s needed, and where the water comes from.
How to find crawl space water problems?
Let’s take a look at the problem. First, go down in the crawl space, and you can see here what we call a core. It is exit drain four as water floods across the floor. It is too high and the same in all homes, especially new ones. They need to put an exit drain in. So they do. You can always find it because they put a piece of six inches with gravel to help keep the debris out. But it goes right outside and doesn’t go anywhere. So, when the groundwater fills up, it backfills into the crawl space.
There’s efflorescence on the first course of the block, which tells you that there’s water in the block, and you can see how wet it is. This crawl space is graded from the very front corner. You can see the water comes down, and it’s supposed to drain during an average rainfall. There’s no place for the water to go when the groundwater fills up.
There’s water, but other things to look for. You start looking at the joist and see how that insulation is dropping. That tells that there’s a lot of moisture even still rising. It looks like a brand-new vapor barrier. So it was probably put down. Then you also look for that efflorescence on the wall, that white powdery substance.
Those are key things. If you see those things in your crawl space, you’ve got a water problem, and you need to deal with it. Otherwise, in the future, these engineered joists will get mold and mildew on them very quickly.
Once water fills up in the ground, there’s no place for that water to go. So it tries to come out of the crawl space but can’t because there’s nowhere to go. You have a crawl space because you have utilities down here, and it’s a better place to put them rather than put them up above. They take up a lot of space.
What’s the best way to eliminate water from the crawl space?
To eliminate any moisture from your crawl space, the first thing you do is find the water’s source. So that involves having an inspection or some evaluation, whether by a professional or you do it yourself. If your crawl space looks like many of the crawl spaces we see, it’s probably not where you want to spend much of your time. So if you don’t want to deal with it, take some advice. Get a professional to do it for you.
First, realize there are three sources from which moisture can come into your crawlspace. The first one is moisture from the outside of your crawlspace. For example, when it rains, or snow melts, the ground becomes saturated with water, the water table rises, and water comes into your crawl space from that source.
Another thing to look for is your crawl space door. Is the crawl space door loose, or are the gaps around it? Is there, not one there at all? If this is the case, it’s another source for outside of water and moisture to get into your crawl space. When there are gaps, the groundwater can run off into your crawl space, or even when it rains, you can have water seep in from the wind blows when it does rain. Likewise, look at your crawlspace vents. If they’re open, the same thing can apply. When there’s rain, there’s wind, which can blow the rain right into your crawl space through the vents.
The second thing to look for in your crawl space for moisture is sources from inside the crawl space. Any piping you have in your crawl space can leak. It can be one of the sources of moisture that you get in your crawl space. Some homeowners in the area have their water heaters down in their crawl spaces. Take a look at that equipment that you have down there. If that leaks or busts, that could be a source of moisture in your crawl space.
The third way moisture gets in your crawl space is from high humidity. So this is the one people tend to forget about when you have hot air on the outside and cool air on the inside in your crawl space. When you have high humidity levels that can cause condensation that you see on the piping and the plumbing in your crawlspace, it can also be why you’ll get wood rot either in the subfloor or the beams in your crawl space. You may also see condensation forming on any crawl space ductwork. You’ll also see the insulation, and your crawl space begins to fail, start to rot and fall and hang because it’s getting wet from the moisture in the air.
Learn more: Why Does A Pencil Look Bent In Water?