Basement Waterproofing Tips

Basement leaks are easy to prevent and even fix without taking a bath

In the 20 years I spent as a professional home inspector, the top three problems my home-buying clients were concerned about can best be summed up this way:  water, water and water!  Waterproofing your home is the surest way to make sure buyers stay interested.

While leaks through roofs, pipes and basements are constant concerns, a wet, leaking basement always ranked highest as the home improvement problem most likely to send buyers running for the nearest open house. 

Whether you are a buyer, seller or owner of a home, wet basements are always a concern. Not only is a wet basement unusable, flooded foundations can be seriously weakened and toxic mold--the newest threat to residential indoor air quality--can fester faster when an ample supply of water lies just underfoot.

Avoid Getting  Getting Soaked By Wet Basements

The good news about these unplanned indoor pools is this: while wet basements are often thought of as one of life's biggest home repair headaches, they are generally easy and inexpensive to fix. Yes, that's right--easy and inexpensive!

The wrong way to waterproof a wet basement.  Ask 10 people how to fix a wet basement and you're likely to get answers that include use of jackhammers to break up basement floors, backhoes to dig out dirt from foundation walls, sump pumps that have to be wired and plumbed, and other such drastic and expensive measures.

While these solutions may seem to make sense, they all attempt the impossible: to seal a foundation so tightly that it will somehow hold off water like a boat. Well, unless your house is a house boat, it won't float, so you might as well stop thinking about all the ways to keep it from doing that.

Most people blame a wet basement on a high water table, the natural level of water in the soil under the building site. This is another myth, because homes are not built below water tables. Builders attempting such a feat would find themselves constructing a foundation in a muddy mess. Likewise, basements that flood after a storm are never caused by rising water tables. A water table moves slowly and seasonally. If basement leaks show up after a heavy rainfall or snowmelt, the cause of your problem is far easier to spot and to fix.

Most basement leaks can be traced to trouble with the drainage conditions around the outside of the house. If  too much water is allowed to collect in the soil around the foundation, it will naturally leak into the basement through the walls, or even up through the center of the floor.

The waterproofing solution lies in improving these drainage conditions, which is easy, cheap and highly effective. Here's where to begin...

Good gutters.  Roof drainage is, by far, the number one cause of basement leakage. Since roof surfaces are as large as the house, they collect lots of water in heavy rainstorms. What happens to that collected water can mean the difference between a wet and a dry basement.

Properly designed gutters should have at least one downspout for every 600 to 800 square feet of roof surface. Gutters must be clean, because dirty gutters fill up and the water overflows directly to where you don't want it: near the foundation. It's also important to make sure the ends of the downspouts are extended to discharge at least four to six feet from the foundation. Spouts which discharge too close to the foundation are like big fire hoses blasting water into the basement.

If your yard and local building laws permit, one of the best ways to control roof drainage is to discharge downspouts into solid PVC plumbing pipes that run underground and release water to the street or to another low-lying area. When making this improvement, be sure to pitch the pipe slightly toward the discharge point to avoid backups. Also, don't attempt this with the soft, flexible black pipe that landscapers like to use around flower beds, because it's easily crushed and cannot be snaked clean like PVC plumbing pipe can.

Sloping soil.  Next to gutter problems, the angle of the soil around the foundation perimeter can also cause wet basement woes. The soil should slope away from the house to keep rainfall from collecting against foundation walls.

The angle and type of soil are also important. The soil should slope downward six inches over the first four feet from the foundation wall. Thereafter, it can be graded more gradually but should never allow water to run back toward the house.

If grading needs improvement, use clean fill dirt (not topsoil) to build up the soil around your house. Tamp the soil down to the correct slope and finish with a layer of topsoil and grass seed to prevent erosion. Or, just use stone or mulch. Whatever the top layer is, be certain the slope is established with the fill dirt, or else the water will just run through the more porous material and into the basement. Also, don't use straight topsoil for the grading improvement. This kind of soil is too organic and will hold water against the foundation, which is the opposite of what needs to be done.

It is also important to avoid landscape treatments that hold soil close to the house. A brick, stone or timber landscape edging around flower beds adjacent to foundation walls may look attractive, but these edges can prevent water from draining away from the foundation and increase your risk of basement flooding.

Following these simple guidelines will solve 99 percent of wet basement blues. These waterproofing improvements are inexpensive and can usually be done yourself or with a little help from your friends.

Avoid panic-peddling waterproofing contractors.  If you've ever thought about hiring a so-called waterproofing contractor to fix your wet basement, don't. Basement waterproofing contractors can often be rip-off artists that attempt to scare homeowners into an expensive drainage system when they're usually not needed.

Several years ago, one of my home inspection clients attempted to fix his leaky basement by calling in waterproofing contractors. Besides telling him his foundation would crumble without a waterproofing system, they offered quotes ranging from $7,500 to $20,000. These were outrageous expenses, even if the system did need to be installed,which it didn't.

Instead, following an inspection, we were able to instruct him on how to correct his outside drainage and easily fix the wet basement problem for under $500--and he avoided getting the soaking of a lifetime from a waterproofing contractor! 

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Comments

Basement Waterproofing

This article makes some very good points. As one of the largest basement waterproofing companies in the country, I don't necessarily agree that 99% of all wet basements can be cured by following your tips. But, we are all for proactive homeowner maintenance and water management. I'd also argue that most basement waterproofers are ripoff artists. There's definitely a fair share of them, but many good ones too.

Water in Basement

Tom, thanks for commenting. Grading the yard with proper soil and extending my downspouts would not of fixed my problem. I agree that it is a good first fix. But there are water issues other then surface water. I understand that by digging around my foundation, I disturbed compacted soil, creating no resistance for the water so it fills my hole very easily. But the fact is that I have no rainfall whatsoever getting in my hole. My land is graded very well now, due to the huge mounds of soil from my hole. Plastic covering my entire hole. All downspouts extend pretty far. So where is the water coming from? So you said it yourself. Higher elevation water flowing to lower elevation. I do not know exact terms of hydrogeology(just looked that word up). I just know that I have a underground water problem. At high rains my water rises from the ground. I can visually see this. Water forces its way to the top from the bottom of my hole. It creates little rivets in the water. All the other websites talk about rising water tables also. Not just websites that are trying to get your money. Your website was the only one that stated water tables rising as a myth. That is my only issue. Water tables rising are a concern. People do build below them. I would still have a water table issue even if I never dug around my foundation. It just would of took a bit longer due to my compacted dirt around my foundation.

Rising vs. Falling Water in a Basement

Dalton, I hear and appreciate your frustration with this issue. However, what you describe is not evidence of a rising water table. Rather, water flows from a higher elevations to a lower elevation. When you dug out the foundation, you inadvertently created a "perfect storm" that no doubt worsened this problem. Disturbing very compacted soil by digging it out, even if the goal was to seal a wall was really not necessary. While I'm glad you seem to be at the ends of this process, I'd respectfully suggest you would have been just as successful by properly regrading your foundation and extending downspouts (assuming you have a correctly designed roof gutter system) away from the foundation by whatever means necessitated by your site elevations.

Eating your words

Few people that commented actually know all this is bogus. I can not believe that you are a home inspector for 20 years and can make statements like these. I am not a contractor or home inspector. Just a do it yourself type of guy that took on the project of waterproofing my triplex. I had water in the basement. So the first thing I figured was, like tom was talking about, bad graded land(which there was) and gutters were not draining far enough from house. But before I handled that I excavated around my entire house(5 feet down with a shovel) to repair cracks, apply a water membrane, protection board, and drainage pipe by footer. I did all that and before I was going to put in my drainage pipe it rained pretty steady for 2-3 days. I woke up with a moat around my house. My wife woke me up with, "baby there is water in your hole". That is a ongoing joke with us now.lol. I knew it was not my gutters or slope because I had plastic all around my house. Like a plastic skirt around my house that was attached to my sill plate to the top of my huge mound of dirt. So it wasn't rain water getting in. I removed my sump pump from the basement and put it outside to pump out my moat. When the sump pump finally removed most of the water there was a steady stream of water(like a river) still trying to fill my hole. This is when I realized that my water table rises after about 2-3 days of heavy rain. After rain it takes about a day or two for the water table to go back to normal. About 12 inches below my footer is the normal water table. This happened a few times because I had to come up with a new game plan. So my point is that Tom is a idiot and I wish I could slap this guy. I don't want to punch him. Just give a a slap of shame for making such idiotic comments about water tables. Let a very dedicated diy'er explain something to you. You must not live in a area that gets rain. Here is how someone builds on a water table. You can build a house in the summer and not know the water table rises during rainy seasons. Your brother probably built my basement with your advice.lol. If two days is a slow rising water table then you are correct. That is not slow to me. MOST leaking basement,if properly done, are very expensive to fix unless you have problems like the gutter or slope. I did all the work my self and still ended up paying a big chunk of change for the materials. I have yet to figure my RISING WATER TABLE out yet. Because if I put drainage pipe next to the footer and drain the pipe to a sump pump. I am going to need a very high output sump pump. And if I drain in to the back yard then the water table will just rise to the point of nothing draining. So my solution was to get a very high output sump pump. Next I am going to make a internal drain system under my slab with drainage pipe that also leads to my sump pump. But I am still worried because I learned that a water table is very hard to pump out at the rate it is filling back in. So I am going to grade the basement floor to my sump pump in case water gets in. I am going to build my sub floor above my basement floor so nothing gets wet. If I have a leak(which eventually I will) it will slope to the sump pump. I have yet to do this because I am making sure I do it right. So if anybody has any advice please inform. Please don't give advice if you agree with Tom.

Hey Tom, A nice article on

Hey Tom, A nice article on basement waterproofing. The tips that you share are really good, I am working for a basement waterproofing NJ company from last three years. So, i know what it takes to fix the problems once and for all. Thank you.

Your timber flooring is also

Your timber flooring is also at risk if there is water leaks throughout the home. I would never waste time with friends advice, no matter how meaningful or experienced. Ensure you have a complete inspection and act promptly.

Basement waterproofing

You know one way you can waterproof your basement? Have a backup plan! We can plan all we want for a disaster and put in extra basement protection, but you know that one day, your basement is going to flood. I recommend people get shurflo pumps and that way they'll know how to avoid a knee-deep mess!

Basement Waterproofing

Taking care of your house is one of the most important things you do. A crack in the basement foundation can lead to bigger and bigger problems. I know people who have tried to do basement waterproofing themselves and it has been a nightmare. If the crack isn't sealed correctly, then you have to grind off whatever you put on to seal it and start over. I personally recommend that you hire a professional. It's your house, it's worth a few dollars more to be sure it lasts.

True

SO many people get so agitated and paranoid from watching home remodeling shows like Holmes on Homes. Of course a lot of what he says is true, and I don't doubt his approach a a contractor, but let's face it, a lot of the time he does unnecessary work for the drama of television. In almost every case of a leaky basement they are digging up the dirt from around the foundation and drilling down into the cement to fix a plumbing issue and then doing their fix. It is in many cases too much! I do agree with the fact that if home inspectors did a better job during pre-build then a lot of these headaches would not be an issue.

Basement Waterproofing

No, Basement waterproofing is not that expensive, but yes to do it the right way, you should dig it out and apply a waterproofing cement product to the exterior of the basement wall. Then you backfill in 2' lifts, compact thoroughly as you come up with a jumpin jack compactor. When you get about 2' below finished grade you layer road subgrade material or Type II, sand & 3/4" rock mix. Compact this layer well, as before, then your native soil. I have installed "french drains" around the perimeter as well to be on the safe side, which daylight out away from the basement. Yes every basement condition is different and not all basements need this application but to do it right, you should apply a waterproof product to exterior of the basement wall. http://www.dimensionbuildlv.com/