Help! Is crawlspace waterproofing a DIY job or should we trust the pricey professionals?

Standing Water in the Crawlspace

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Help! We have a continual problem with standing water in the crawlspace of our fairly new home. We had estimates from several waterproofing companies to fix the problem, ranging from $750 to $6000! The pricing seems quite suspicious to us. The more expensive offer was reduced to $4000 if we would "let us put our company sign in your yard for 30 days". Twice we were offered a reduction because, "this rarely happens--we have a couple days of free time and we want to keep our crew busy, so we can fit you in this week!" The salespeople are also quite "high-pressure". These are all red flags to us, but we know our crawlspace has a problem and we don't know who to trust for a true estimate. This same company brought out a water meter to test our cement blocks and supposedly they are filled with water and will eventually rot away (the house is only 5 years old). The company with the low estimate knew ahead of time that we don't have much to spend on the problem and we're afraid they're giving us a temporary solution that will cost more money years from now when our foundation gives way. Help! Does anyone have experience with these companies or can you suggest a do-it-yourself crawlspace waterproofing solution?

Concrete and Sump Pumps

We had a problem with water in the crawl space of our home. We researched many options to eliminate the water and spoke with many companies (hearing much of what you did). The option we ended up with was to pour concrete in the basement and install two sump pumps. It is a good idea to have two sump pumps for a large home and also in the event that one stops working. The concrete helps to get rid of dampness, mold, and mildew and keep the water out. The floor must be properly graded. The concrete is the most expensive of the two options (with a layer of stone underneath) - maybe you can get by with just the sump pumps and possibly a layer of stone on top for drainage. The way we found our contractor was to check with our neighbors...if we had water we figured some of them must, too!
Brenda L., New Jersey

Related: Insulating a Crawl Space

We Did It All

When we bought our house, even though it had standing water under it, we were told a sump pump and gutters would probably fix the problem. Wrong, the gutters did nothing but cost money and need to be cleaned out, and the exterminating company who suggested the sump pump was going to put it in the wrong place. We had to bite the bullet and have it waterproofed, including gravel, black plastic pipe, holes drilled in the cement blocks to let the water out, absorbent pink stuff against the blocks to keep future water away from the blocks, rubber sprayed into the earth outside the house to keep water out, sump pump under the house, plastic pipes run from downspouts away from house, spraying of wood foundation twice to kill mold smell, and gravel & metal things around the window wells to keep water out. We got a few quotes and the professional waterproofing company we hired had been in business for something like 15 years. They guaranteed their work for life and the sump pump for 20 years.

I would suggest you check what is included in each quote against the other quotes. You should also check with your local better business bureau to be sure there are no complaints on anyone you are thinking of hiring. Be sure to check the work that is done against your contract to make sure they did everything they promised, since a lot of times the person doing the quote is not the one doing the work.
Carol S

Have Home Inspected Professionally

I would like to suggest a home inspector. Their job is to assess damage to a home and do not have any association with the repairmen, meaning they won't tell you something needs to be fixed if it doesn't. The cost of hiring a home inspector would be a consideration however. We hired a home inspector to inspect our home before buying it. The furnace in the house was old, however in excellent condition. He told us to be sure no one told us we needed a new furnace, unless we wanted a more efficient one. Well, sure enough, when we had our heating ducts cleaned by a company, the guy told us we needed a new furnace, that our old one was giving off carbon monoxide gas! Even though we had gotten previous assurance, I called the home inspector and he even came back to our house and preformed several tests to again confirm that our furnace was fine and not giving off carbon monoxide. In our case, the money to hire the home inspector far outweighed the cost of buying a new furnace.
Kimberly I-H.

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Grandpa's Advice

We had a similar situation with the crawl space in our old house. I'm not sure how much water has collected in the reader's crawlspace, but ours was always somewhat muddy. Occasionally after if rained, I could find small puddles of water. I really didn't care about the moisture in the crawlspace, but it was causing mildew and mold in the closets and other dark areas in the walls of the house.

We were also taken in by so-called basement and crawlspace waterproof experts. We got similar estimates for repairs (also, once these people get you on their phone list, they are impossible to get rid of!). I was nearly ready to let one of them fix the problem, when my grandfather gave me some tips that solved the problem.

First thing is to make sure you have good cross ventilation in late spring, summer, and fall to help carry the moisture out. All I did was open the vents on both sides of the house. This seemed to help somewhat but didn't completely solve the problem.

Next, I went and got large rolls of plastic (mylar, 6 or 8 mil) tarp and duct tape at Lowes. The total cost was about $60 for around 1000 sq ft. Make sure the plastic completely covers the block and you seal any holes in the plastic with duct tape. I also used the duct tape to secure the plastic along the top of the walls. You could also staple the plastic to the wood that sits on top of the block walls.

It took me the better part of a day and was a bit dirty, but I saved quite a bit of money. Also, I fixed the problem. The house was dryer, and the mold and mildew was no longer a problem. I'm also told that just sealing the block walls would not have prevented the moisture build up in the soil (which was really the problem).

A Perimeter Drain

I had this same problem when I moved into my house, which is now 22 years old. My advice is to have the water problem taken care of as soon as possible. Standing water in a crawlspace will eventually rot your floor joists and sill plates just from the moisture level alone. It is possible that your block is full of water, but I'm not sure about the block "rotting away". It surely isn't full year round. I paid $4000 for a reputable contractor to install a perimeter drain inside my crawlspace, which consist of 4" perforated PVC, backfilled with gravel. The drain was tied into my existing sump pump. Holes can be drilled at the bottom of the block to let any water drain out. Most of the cost was labor. The materials aren't more than $1000 but it is a very labor intensive job if you plan to do it yourself. When getting estimates, check with the Better Business Bureau, and ask the contractor for references. If they have a problem with this, then they don't stand by their work. The bottom line is have it fixed, because the consequences of letting it go are costly. Trust me, I know.

Sump Pump Worked for Us

I too have experienced the problem of a crawl space collecting water (A lot of water). My husband and I were advised to correct the problem quickly as the moisture can ruin your floor above. However we couldn't afford to do anything costly but we knew a plumber and he installed a sump pump in the crawl space. The pump kicks on when it senses a certain amount of water. Ours was a middle of the line model but it works great. The pump cost about $175.00 and the labor was about $130.00. It may require a few more materials but definitely cheaper than you might think. Nothing was said about our foundation and we had a lots of standing water in our crawl space so that would be questionable.
Jamie W.

Ask the Builder

I suggest you contact the builder. There should be some kind of warranty that would cover exactly this kind of thing. Even if not under warranty, most home builders are very concerned about their reputation, and are willing to fix problems like this that are obvious design/construction problems. If they are not cooperative, apply a little pressure, i.e., letter to the editor, local troubleshooter/ombudsman, hang out in their model homes explaining loudly to the sales staff about the problems you're having, etc.
Loring F-P

Don't Wait

I would make sure the reader does not let this problem continue. Water around the foundation of a house can freeze and break the foundation. A broken foundation will cost much more than even their expensive $6000 repair price they were quoted.

If the reader can gain access around the outside of the foundation wall directly or by digging away the dirt, he should apply a thick layer of creosote to the walls. Plastic sheathing and stones (and perhaps even drain tile) should then be installed around the walls before putting the dirt back. A sump pump inside the crawl space would probably be good to add to pump whatever water still finds its way back in. Another thing the reader should keep in mind is to make sure the grading goes away from the house. The general "6 in 10" rule applies here. Namely, there should be at least 6 inches of grade away from the house over 10 feet.

The reader does not say what each waterproofing company plans to do for the amount quoted or what kind of guarantee is being offered. Without that info, it's impossible to compare these prices to tell him which is the best deal. I would tell the reader to make sure each company says how they intend to correct the problem and compare their approach to the information I gave above.
Mark S

Inspect the House Yourself

I just went thru this so I might have some insights. I bought a house and the inspector gave me some ideas, then I went and got some great info from the internet. Use those companies only as a last resort. First of all, follow these steps.

  1. Fix your gutters. An average house collects 50,000 gallons of water. If this water lands right near your foundation, guess where it ends up? Make sure that your gutters are not clogged up and they do not leak.
  2. At the downspouts, attach pipes to lead the water about 10 feet away from the foundation walls. You can find corrugated pipes and adapters at Home Depot.
  3. Walk around your house and make sure that there is a a slope away from the foundation. Fill up any low spots near the foundation. If you have any raised bed foundations near the house, make sure that water does not pool between the bed and the house. If necessary, add some earth to create a slope away from the foundation.

If none of the above steps work, I suggest that you install a french drain (a pipe which will take water away from around your house to some place furthur on).

If all of these steps do not work, only then get one of those companies. To learn more about french drains and lots of good stuff go to Tim Carter has a great site with lots of great information (I have no relationship with Tim Carter).

Check for Drainage

I had this problem with my home in TN. Take a look around your crawlspace. There should be several blocks with holes leading outside (3-6" in diameter) at ground level. These are for drainage. Trace them outside. When I dug down to the black plastic pipe that drained the crawlspace, I found that it had either collapsed or was missing entirely. One piece was pitched towards the house instead of down, away from the house. It may tear up the grass, but in my case, it saved me several hundred dollars of repair bills for a few hours of digging and a couple handfuls of grass seed. This was suggested to me by TVA before they installed my heat pump.

Reviewed January 2018

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