Moisture and Crawl Space

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abw688

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Hello! We just bought our house in May and the inspector said the crawl space looked good and was dry. He also said there is a french drain system in the crawl space and a sump pump. We are on the downside of a hill in our neighborhood and have noticed that when it rains, we get some water pooled close to the house.
We also live in SC and have had quite a bit of rain the past couple of days and checked our crawl space today and saw that there was water in it on the lower elevation but our sump pump is working and pumping water out.
I was nervous about the water in the crawl space and was wondering if we should do anything? I am also not sure since the inspector said everything looked good, dry, and clean. I am not sure if it is just the significant amount of water or what.

Any advice would be great! Thank you!

I also wanted to note the home was built in 1986
 
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Does your crawlspace have all the ground covered with plastic? Is the water on top of the plastic or below?

Is water gathering in low spot and not making it to the perimeter drains? If so, fill the low spot to have the water drain towards the perimeter drain tile.

Where does the sump pump discharge its water?

Does the land around your house slope away for at least 10 feet?

Do have gutters? If so, how far away from the house do they drain out?

Is there standing water in your yard right now? I know SC has gotten hammered this weekend. I'm to your north in NC and we're heading to our 12th day in a row with measureable rainfall.
 
We do not have a vapor barrier (so no plastic)

My house is on a hill, so I am not sure if the crawl space is level. I do know that the water is more at the one end (heading down the hill and where the sump pump is).

The land around us does not slow away unfortunately. Water comes from my neighbors yard, flows through my yard, and on to the next yard, etc...eventually going into the street.

We do have gutters. We could have them drain farther away from the house. My only problem is that there is an area in the back of the yard where the water just pools (it is close to the house) and the backyard and front yard seems to slant towards the house. We thought about putting in a drain where the water pools and having it go into the street but it would have to run up an incline and I don't think that is possible or else run into our neighbors yard which I don't think we'd want to do.

Right now, there is standing water in the yard. I was wondering if I should try to push it out somewhere. Yes, this is the most rain we've ever seen! It's awful down here! I hope you're staying dry in NC!!
 
I'm surprised your building inspector didn't advise to cover the ground with plastic. It should be covered with plastic to keep moisture from the ground out of your house.

Piping the water uphill would require a pump. It is best to handle the water above grade if at all possible. Filling in low spots so the water drains away from the house would help.

With respect to the grading, you want swales around the house to divert the water coming down the hill away from your house and towards the natural or manmade drainage at the low point of the area. My own house sits in the middle of a hill, and the water does a pretty good job of following the swales away from the house. I have a full basement, walk out, that has never had a drop of water come in from the outside. I don't have a sump pump but I do have footer drains around the house and the slab is poured over gravel and a plastic vapor barrier.
 
You have had a lot of water lately so this problem may not be the norm. But it is nice to know what happens with a big rain. You will want to get down there dig some trenches to all water will find it's way to the pump and fill those tenches with a gravel, that will keep the dirt out of the sump and then add poly to keep the moisture away, You do want vents in the area, I think.
 
We had 11 inches of rain in the past 48 hours so this has been a significant rainfall for us! I know my neighbors all have water in their crawlspaces as well, but unfortunately, do not have sump pumps. The pump has been pumping water out all day and I cannot see any visible water in the space anymore...however, the pump is still working (I am guessing it is pumping the water out coming from the French drain system.

On a normal rain, water does tend to pool near the house but I am not sure if the crawl space ever gets wet. I will try to add more soil to get the water away from the house (once we dry out!). My husband and I have already decided to get the vapor barrier put in. We did get a quote from our termite company...$525.00. We have vents in the foundation right now for the crawl space. I have heard a full crawl space encapsulation is not good for termite bonds on homes (which we have one) as it can often void the bond.
 
11 inches would be a good test for any system. I am not a fan of incapsulation, espesially when there is a chance of water in there. Carefull not to raise the dirt around the house to much, best if you have between 6 and 8 inches of foundation visable above ground.
 
Yes, alot of water! I had 3 people under the crawl space (home inspector, 2 different termite inspectors) that said it was dry and no wood rot) so, I am guessing this is just a result of all unusual massive amounts of rain we have.

The foundation is brick and is higher at that end of the house as my house is on the hill. I wish we could do a drain system of some sort, but it seems like there is no lower grade except my neighbors yard (going down the hill)....my sump pump pretty much drains on their driveway.

I am guessing the water gets in their from up under the soil? I am not sure how else it would get in there. I was worried about water getting on top of the vapor barrier if one is installed. Would the contractor installing have an idea?
 
The vapour barrier should be sealed around the edges to the foundation, the french drain below should look after the water, your contractor should make sure all water is being picked up by that drain. The vents should look after anywater that does get on top of the barrier.
 
The vapour barrier should be sealed around the edges to the foundation, the french drain below should look after the water, your contractor should make sure all water is being picked up by that drain. The vents should look after anywater that does get on top of the barrier.

Thank you for all the information! I looked into how they do the vapor barrier and it looks like they seal it to the foundation walls (I thought they just laid plastic on the ground and covered it with gravel). We're going to look into having it done in the coming weeks. I am thankful to have the French drain and the sump pump. I have no idea how my neighbors will get their water out! It's hard to get water out of a space that is only 2 feet tall!
 
Thank you for all the information! I looked into how they do the vapor barrier and it looks like they seal it to the foundation walls (I thought they just laid plastic on the ground and covered it with gravel). We're going to look into having it done in the coming weeks. I am thankful to have the French drain and the sump pump. I have no idea how my neighbors will get their water out! It's hard to get water out of a space that is only 2 feet tall!

When I was a kid I worked for an outfit hooking old houses to new city sewer system, some were just 1 ft and full of mud, ugly work.
 
Just checked our crawl space this morning....looks dry except for a larger puddle by the sump pump. Thankful the pump pumped all the water out for the most part. We are going to shop vac the water out that is standing there and put a large fan in for the day to circulate the air (we have vents in the space). Do you think that will do the trick? Also, would a box fan work? I read that those would be fine, but wanted to check before we get going on this today! Thanks!! We're going to have the vapor barrier installed in the coming weeks.
 
I think it would be best to use a fan that sucks air out of a vent. So, as it picks up moisture it is out.
The dirt should be re-arranged so water always gets to the pump before you cover it up.
 
Try not to over-react to the recent rainfall. It sounds like your current system did an admirable job, considering the amount. Have you talked to your neighbors about their strategies for drainage? You can learn a lot from the veterans of the area. I'm not saying you shouldn't do the things mentioned here, but how has your house handled the normal rains so far?
 
Try not to over-react to the recent rainfall. It sounds like your current system did an admirable job, considering the amount. Have you talked to your neighbors about their strategies for drainage? You can learn a lot from the veterans of the area. I'm not saying you shouldn't do the things mentioned here, but how has your house handled the normal rains so far?

Both neighbors on either side have lived here for at least 7 years and have said that they never have had water in their crawl space, so I am guessing this is not the norm. When our inspector and termite inspector checked our crawl space, both said it was in great condition. Water usually pools a bit near our house, but I am guessing it has never been like this before.

I think I am just very nervous because we just moved in and I am so afraid of having a damp crawl space. I think most of the time, they are damp to some extent? I am just worried that there was that much water in there...but it was in and out in 24 hours as there is no standing water or muddy areas that I can see. There is also a tremendous of gravel on the ground in there so I am not sure if that helps?
 
Covering the ground with plastic will help control the moisture. Being in SC you, like me, have very humid weather to deal with. An encapsulated crawlspace can help with that, but you need to condition the crawlspace to do it. Meaning putting HVAC into the space. The AC will dry the air. I suppose your could dry it with a dehumidifer as well, but as long as the vents are open you're going to be attempting to dehumidify South Carolina. No small task.

Here is a little reading on the subject:

http://energy.gov/sites/prod/files/2014/01/f6/1_1d_ba_innov_unventedconditionedcrawlspaces_011713.pdf

http://www.probuilder.com/crawlspaces-vent-or-not-vent
 
I looked into the encapsulated crawl spaces and have heard mixed reviews. Plus, this is our first house and not sure how long we're going to be in it...so not sure if I want to go ahead and dump that much money into it.

We had someone go under there today to check our duct work. He did say it was thick muddy, but did not see any standing water. He said most of the crawl spaces he's been in since the flooding have been muddy due to massive amount of rain. He suggested just airing it out and having the box fan point outward.

Questions....how long do you think it will take to air it out? We're going to have dry weather for the next few days and we're going to keep the fan going down there. Other question, does it need to be 100% dry to get the vapor barrier in? I think we're going to go ahead and get that in there. I imagine the company would not put it in if it was not good to do so.

My main concern is keeping water off the barrier once it's in. We have the french drain on the inside and a sump pump on the lowest grade in the crawl space so I am just not sure what else we can do.
 
Our newer houses always have samd in the crawlspace with skim coat of concrete over the polysheeting so if the is water getting under there and then draining out you would never know. If this is rain water causing mud and you can't do more for better drainage, I would just cover it up Make sure they seal the vapour barrier to the concrete, we use accustic sealer for that and make sure they tape all the joints (Tuck tape)
 
Have you checked under the gravel to see if the plastic is there?

Yes, it is not :( I heard the plastic that gets sealed to part of your foundation works better than just plastic on the floor. So, I think that might be a good option?
 
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