I own a 1920’s Spanish stucco house in Los Angeles (No Los Angeles jokes please). We have a problem with an intermitently damp crawl space. The California basement (concrete) portion is dry, but the earth in the crawl space on one side of the house is moist – not quite mud, but definitely moister than it should be. It has been dry all winter – even during the rains – but now, all of a sudden it is wet again. I hired a “leak detection” company, and they said to replace a shower pan (which we did – along with the rest of the bathroom!) but didn’t find any other leaks. I called in a “basement encapsulation”company, but they discouraged me from encapsulating the crawl space since the house is in California(?!?) and that would only cover the problem up, not fix it. I am at a loss as to what to do now. I really want to fix the problem – if I only knew the cause. What kind of contractor or tradesman should I hire to solve my “case”?Oh yes, we live on a slightly sloping street and the dampness is on the uphill side, if that makes any difference.
I greatly appreciate any help.
Replies
your moisture might be coming from upslope of your house or even your lot. You didn't mention what, if anything is upslope of your house, but with all the unusual volcanic strata in California, the moisture could be coming from quite a distance. You would believe, however, that it would be worst during the rainy season.
One particular solution, if it bugs you enough, would be to trench down three or four feet upslope of the foundation and install a french drain. That would consist of 4 inch perfed plastic pipe inserted in a fabric sleve and covered in pea gravel. The pipe should rest on the bottom of the trench with the pea gravel above. If the soil in the trench on the upslope side is quite moist or wet, I would fill most of the trench with the pea gravel, cover with cloth to keep the soil from leaching down through the pea gravel, and then back fill the upper foot or so with soil.
Also, because you are working on a slope with suspect soils, be very careful of cave-ins in the trench. Even a four foot deep trench will do major harm to your body if it collapses when you are standing in it. Southern California has lots of adobe clay and it does wierd things when wet. Usually can't get it off a shovel, but when it gets wet enough, it gets very greasy. You might need a city or county permit in your area, even for a french drain, especially if you run the outlet down to the street where it might empty across a sidewalk or upon a city/county street.
If you begin digging trench and run into a lot of water, get hold of a soils engineer. It may cost a few bucks but might save a life or your house.
If the moisture bugs you only a little, how about a fan that might draw air into the airspace and out the other side.
Thank you for your very informative response. My house is located in a regular older neighborhood. My upslope neighbor's house is the width of 2 standard driveways plus about 8 feet away. There is a 6' tall stucco over cinderblock wall between us, which I assume has about a 3 foot footing on the lower side. My neighbor's yard is about 18" higher than ours on the side closest to our house. The lots are about 75 feet wide with about a 2-3' elevation change from one side of each lot to the other. It is just sloped, not terraced.
The soil just outside the foundation of our house feels dryer than the soil in the crawl space which makes all this that much more confusing.
Thanks again for your input.
Before you go trenching the 3-4 feet that Dennis suggests, dig a few test holes in that area and see if that's where the water really comes from. If it is from uphill, you need to figure out if it's a neighbor watering plants or emptying a hot tub or something. If it's not a neighbor, intermittent natural springs are a possibility here, and you need expert help. If this is on adobe, I'd expect to see foundation trouble from the intermittent wet and dry conditions. The way that stuff expands is amazing, it produces tons per square inch.
I'm in LA too, my crawl space is dry as a bone and hard as a rock. Where in LA is this?
John: Thanks for your reply. My house is in beautiful Pasadena. The water may be coming from the neighbor's garden, but I don't understand why it didn't get wet this winter when it rained (like it did before we replaced the rain gutters and down spouts). I think the abandoned drain or pipes are a good possibility, but it seems like it would be wet from those all the time too, not just intermittently.
Most of the crawl space is dry, especially on the downhill side of the California basement. We have lots of vents so air circ. is not a problem. We don't seem to have soil expansion problems. None that are visible anyway. But I am concerned about mold (there is a musty smell), rot, pests, etc. that would accompany moisture. Also, there is a mineral "florescence" on some of the concrete.
What kind of expert help would I hire? I've tried plumbers and "leak detectors". I am ready to hire a dowser!
There are a lot of reasons you might have moisture in the crawl space. As others have said, there might be water moving under the soil and getting your crawl wet. My last house had an abandoned surface drain that was routed under the house in clay pipe that had collapsed about halfway thru the crawl space. A part of the crawl got very wet when it rained, and I could not figure it out until I was doing some foundation work and found the pipe buried about 6 inches deep. Where do your downspouts go--into pipe or just onto splash blocks? Are your neighbors growing and watering a garden right next to your house? Any chance of abandoned plumbing or something like that?
Since the sun don't shine in there, it takes a LONG time to get dry again. Do you have adequate ventilation? Building code defines adequate as 1 square foot of ventilation area per 150 square feet of footprint. Most people with wet soil in the crawl put down a vapor barrier--6 mil black poly is typical. Methods of installing it vary--some people run it up onto the foundation and glue it in place. There's a lot of debate about ventilation and vapor barriers in crawl spaces, but I'm a firm believer in plenty of both, and put in enough vents so that it's windy under my house.
David: Thanks for your response to my post. The house used to have gutter drains that went under the house and out somewhere else, but those have been abandoned for years. Suprisingly enough, it doesn't get wet under the house when it rains. It is intermittent.
We have plenty of air cirulation and the crawl is dry as a bone on the downhill side of the house.
Any idea what kind of "expert" I would hire to help solve this problem? I have tried plumbers and a "leak detection company" and they were no help. I though I might have solved the problem when we completely replaced the bathroom including the shower pan. But 3 months later, the soil is damp again.
A clever general contractor is the starting point. I get called to go look at things like that frequently. A drainage contractor would also be a good idea. Basically you are looking for someone who can approach it as an interesting puzzle as opposed to a job estimate.
David: Thank you. You are da' Bomb!
Another thought... a home inspector. There's one home inspector here and he's an exceedingly clever guy. I call him sometimes with really strange questions and he always straightens me out. A lot of home inspectors used to be GCs and are used to sizing up problems. Call a couple of realtors and ask who the smartest inspector is. Call that person and ask if they can perform a brief inspection for you... they don't need to go over the whole house, wiring, HVAC, etc., just figure out the water issue.
I looked at a house a month ago with a sopping wet crawl space. It was close to and lower than a very large pond. I suspect the pond is keeping the soil wet, since it hasn't rained seriously in three months.
Thanks, Dave. I'll call the inspector that I used when I bought the house.
"Call a couple of realtors and ask who the smartest inspector is."
Most Realtors avoid them like the plague, cause they call them "deal killers"
The best hint so far is the white stuff on the foundation wall, it means the moisture is coming from the other side of the wall.
For leaking plumbing, your ears are the best detector. Run water thru all the drains and have the shower head hit the tub rim and overflow. Lay under the house and you will hear that drip hit the ground or see that drip hanging from the joist.
None of the major plumbing repair companies in the Yellow Pages have the expertise to solve your problem.
"Most Realtors avoid them like the plague, cause they call them "deal killers""
That seems to be very regional.
In this area I have gotten the impression that most real estate agents feel that the inspectors CYA.
In fact a friend of mine has an upset client that did not want inspections and how has found some problems.
"For leaking plumbing, your ears are the best detector. Run water thru all the drains and have the shower head hit the tub rim and overflow. Lay under the house and you will hear that drip hit the ground or see that drip hanging from the joist."
That won't help if the leak is in underground supply lines or drain lines.