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 leaks

My basement wall is made of cinder blocks and water was seeping through the walls. Since listening to the money pit. I have cleaned my gutters, repaired any leaks in them and and built my soil up so that it was sloping more away from my house. I can honestly say it's been 2 weeks and my walls are currently not seeping and it has been raining. Great tips!

My neibor "land little be

My neibor "land little be above mine, & now we have slope toward house & wet basement every time when we have heavy rain. I coudn't do anything myself, because a lot of roots there, do you know that what type of company can help me, and should i go to City Building, or some other department for help? I now that my english it's not good, and question not smart, but i need to solve this problem

wet basement

during a recent storm my roof was damaged by high winds. Shingles were ripped up and i noticed alot of water in my basement. The rest of my house is dry but basement walls damp and floor soaked. Does anyone know if its possible for water to trickle down house not wety first or second floor but soak my basement?

Leaky Basement wall

I have a minor leak at the base of my basement wall. This wall has a lot of soil from a hillside resting against it. I am starting to get staircase cracks along the joints as well. the cracks are not very large. I have heard drylock can take care of this but I want to be sure this is not a quick fix. What else can I try before this situation worsens. I do not have a sump pump or french drains. Also, I moved into this house about 6 months ago. I have a deck on the backside of the house on the outside of the leaky basement wall, so I cannot alleviate the sloping problem unless I demolish this deck. Please advise. Thank you.

Wet Basements

Tom,I agree with your answer,proper grading and eaves troughs and down spouts,solve most problems.
Most home owners are not aware that the earth around the foundations ,settles slowly over time,and after a while water runs towards the house not away from the foundations,
Also the home owner needs to keep the debris out of the window wells and ensure down spout extensions are at least 4 to 6 feet long and to be sure to replace the extensions after cutting the grass
As you started,why not try the easy way first
Harry

High Water Table

I have sump pumps, one of which runs constantly. I water table is so high the pump runs 3-4 times per minute. What can be done to redirect the water so that the pumps are not running all the time?

Multiple pumps, battery back ups and now I have to get a generator to make myself sleep at night> Any suggestions?

wet basement

OK, since the weather is supposed to be nice this weekend we're going to give it go with the gutter and grading improvements, however, I have a question, my house sits almost on top of a hill, Almost being the opportune word there. The back of the house is what seems to catch the water off the hill, since the house sits on a downward slope how can I grade the back yard to minimize the water pooling at the back of the house?

Wet Basements

I spent 20 years diagnosing basement water problems as a professional home inspector and the regrading and gutter improvement approach works in all cases, except when a high water table is present, which is actually far more rare than most people believe.  In any event, there very little risk in trying out gutter and grading improvements and a ton of risk that you'll waste money hiring a water proofing contractor.  So, what have you got to lose by tying the easy way first?

Wet Basements

Even though I want to believe this, I know from years of experience that this is unreal. If I have learned anything it is that you can not waterproof a basement from the outside of the home. No matter how much you regrade, or how great your gutters are, the final outcome in a heavy down pour is a wet basement.
I had it up to my ears, litterally and decided to hire a waterproofing contractor. Not every contractor is the same and yes it can cost a lot to fix the basement but given the right contractor you can fix the problem indefinately not just put a band aid on it like specified in this column. I spent many a year trying everything and nothing worked except having my floor jacked up and a waterproofing put in.