Make Your Wet Basement Dry in a Week!

How To Repair a Wet Basement by RadonSeal

HELP! I Have a Wet Basement

Did you know that most new homes develop basement leaks within 10 to 15 years and that "Over 60% of basements have moisture seepage, while 38% experience mold and fungus growth due to an elevated moisture level." The American Society of Home Inspectors

Traditional, decades-old basement waterproofing methods have not passed the test of time and wet basements have become the most frequent complaint of homeowners. What to do? If your basement is already leaking, you could hire a waterproofing contractor to install the standard interior French drains with a sump pump. Or, the contractor may recommend excavating down to the footers and waterproofing the foundation walls on the outside.

Sounds good, but these waterproofing methods are not cheap! On average, exterior waterproofing will run you $15,000 (not to mention having to replace landscaping or even sidewalks) while interior perimeter drains plus a sump-pump could cost a homeowner around $6,000. You may be asking yourself, "Could I potentially repair the wet basement myself? However, I am not what one would call a "do-it-yourself-er."

Locate Where the Water is Coming From

The first line of basement waterproofing defense should always be made on the outside. Divert rainwater away from the foundation by proper grading, gutter maintenance, downspout extensions, crack repair, window well covers, caulking, and waterproofing concrete, brick and masonry. These simple steps can go a long way to achieving a dry basement, but by no means are they the end-all solution.

Secondly, locating the source and knowing why your basement leaks on the inside can make a do-it-yourself waterproofing project surprisingly simple and inexpensive. Review the table below for the common reasons why basements leak and how to repair your wet basement:

Basement Water Leaks Causes Basement Waterproofing Products
Capillary water seepage through CONCRETE BLOCK WALLS Waterproof concrete blocks using RadonSeal Plus & Ion-Bond Armor.
Capillary water seepage through POURED CONCRETE WALLS Waterproof using RadonSeal Deep-Penetrating Concrete Sealer.
Water vapor, water seepage through BASEMENT FLOOR Waterproof slabs using RadonSeal or waterproof and color stain concrete using LastiSeal Concrete Stain & Sealer.
LEAKING CRACKS in poured concrete foundation walls Repair leaking cracks in foundations with DIY Foundation Crack Repair Kits or Professional Crack Injection Toolkit.
LEAKING CRACKS in concrete block foundation walls Repair cracks in cinder block walls using ElastiPoxy Crack Filler Kit.
WET CRACKS in basement floors Quickly repair floor cracks with CrackWeld Concrete Floor Repair Kit.
Water seepage through BRICK WALLS
Waterproof bricks and mortar with LastiSeal Brick & Concrete Sealer.
Water seepage through FLOOR-TO-WALL JOINTS Repair leaky joints (indoor or outdoor) using ElastiPoxy.
GAPS or SEPERATIONS between floor and foundation walls Fill floor-to-wall voids with ElastiPoxy.
EXPANSION CONTROL JOINTS or SAW CUTS Repair control joints using ElastiPoxy.
Leakage around PIPES/CONDUITS through foundation wall Seal leaking penetrations with PipeTite Gap Filler Kit.
Leaking WIRE TIES Waterproof wire ties with PipeTite.
MAIN SUMP PUMP FAILURE First, replace the main pump! Second, install an emergency Water-Powered Backup Sump Pump.

How To Waterproof Wet, Leaking, or Damp Foundation Walls

Foundation walls will appear wet or start seeping water only intermittently after heavy rains. You may also notice spots of efflorescence ("white powder") on the concrete surface which is a telltale sign of capillary water seepage. If this sounds all too familiar, now is the time to act before your wet basement gets worse making repairs much more difficult.

If your foundation walls are already wet or leaking, allow the concrete to dry out for the best basement waterproofing results. You can speed up the drying time by drilling weeping holes in the bottom of concrete blocks, installing a fan in the basement to improve evaporation, or simply waiting for dry weather. Once the concrete is sufficiently dry, seal the foundation walls with RadonSeal.

Why RadonSeal? RadonSeal is not your average cement waterproofing sealer like those found in big box stores. Waterproofing paints, cementitious coatings, and membrane coatings will eventually loosen, crack, or peel, as they are pushed off by hydrostatic water pressure, trapped water vapor, and efflorescence. It could take a couple to several years, but eventually all waterproofing paints or coatings will fail needing to be reapplied again. A big problem if you have already finished the basement!

RadonSeal is different! Negative side water pressure and efflorescence cannot budge it. Once cured inside the concrete the internal seal is PERMANENT, which is backed by an unmatched limited lifetime money-back warranty! RadonSeal works by penetrating deep into the concrete (up to 4"), chemically reacts with lime and alkalis, expands inside the pores, and cures as a mineral. It waterproofs concrete internally against water seepage, water vapor, and even against radon gas. RadonSeal combines concrete waterproofing, damp proofing, concrete preservation, and radon mitigation in one sealer!

If you want painted basemen wall, you can always apply a waterproofing paint after you have deep-sealed the concrete with RadonSeal. That will protect the waterproofing paint against water, moisture vapor, and efflorescence.

Sounds to good to be true. What's the catch? – There is none. RadonSeal does not change the appearance or surface profile of the concrete, contains no chemical solvents or VOCs (bonus!) and can be easily applied using a hand-pump "garden" sprayer (or paint roller).

Do-It-Yourself Solutions that Will Save You $1,000's

Whether you need to waterproof a new or old basement, damp concrete floor, wet concrete block wall, crawl space, stone foundation or leaky brick wall, RadonSeal® has a long and well proven history (est. 1997) of providing expert customer service and the most advanced, professional-quality basement repair products on the market. Our line of concrete sealers, foundation crack repair kits, and concrete floor repair kits are not only for professionals but also easy enough for use by the average homeowner.

Instead of investing in cookie-cutter waterproofing systems, which may not perform well or for very long, do-it-yourself basement waterproofing can be accomplished with a little know-how and by using the best products for your specific basement leak(s). We guarantee you will get long-lasting results without having to break the bank on expensive waterproofing methods.

We know from 15+ years of experience that basement waterproofing solutions are not always clear-cut! If you have questions about your basement or a particular project please contact a RadonSeal® service technician for expert advice.

Review customers feedback and tips on Waterproofing Concrete, Wet Basements and Crack Repairs

How To Waterproof Damp Concrete Floors

Many homeowners have found out the hard way that paints and coatings alone are just not suitable for concrete floors. Latex-based waterproofing paints are too soft for floors. And if you apply an epoxy or urethane coating, concrete floor paint, or concrete overlay, years of water vapor pressure and efflorescence coming through the concrete pores will soon enough make it to fail, crack, or peel.

Seal Your Basement or Garage Floor - The proper method is to deep seal the concrete floor first with RadonSeal Concrete Sealer. RadonSeal provides the permanent waterproofing solution for concrete slabs by stopping capillary water seepage due to hydrostatic pressure or wicking water. It also restricts the inflow of water vapor through the pores. It practically eliminates efflorescence and concrete dusting. RadonSeal does not change the surface appearance or profile, leaving the concrete suitable for paints, adhesives, tiles, flooring, epoxy, and coatings. It is as a great primer!

Use RadonSeal to preserve or dry out wet basement floors, garage floors, concrete driveways, patios, and pool decks. RadonSeal is not designed to seal cracks or gaps – you may need a crack repair kit.

How To Repair A Leaky Concrete Floor Crack - A popular method is to route out the crack 1/4" wide by 1/2" deep and fill it with self-leveling caulk or hydraulic cement. But the caulk or hydraulic cement are certain to get loose and you have to route it out again.

Instead, permanently repair the crack using CrackWeld Concrete Floor Repair Kit (pictured). It provides a strong, full-depth repair of cracks in concrete slabs, be it hairline or 1/2-inch wide. Stronger than concrete – the crack will not move, get longer or wider. And there is no need to chase the crack before application.

CrackWeld concrete floor repair kit

Foundation Crack Repairs Made Easy

Most homes, both new and old, develop a crack or two in foundation walls. If the cracks aren't leaking, it is only a matter of time till they do as the exterior waterproofing coating gradually deteriorates. So, if your basement cracks are not leaking yet, now is the time to repair them to avoid water damage and potential mold growth.

When it comes to foundation crack repair, temporary fixes simply do not last. Caulk will peel. Hydraulic cement does not bond well to concrete and will eventually get loose, letting the water in.

Repairing cracks yourself may appear to be a daunting task but surprisingly, it is quite easy. RadonSeal DIY Concrete Crack Repair Kits or Professional Kits allow you to repair cracks in poured concrete walls like a pro! You will save $100's and the repair is permanent!

Water Seepage through a Leaky Floor-to-Wall Joint

The most common complaint from homeowners – "Water is coming up from the corner floor-to-wall joint!" Or, "There is lots of water pushing up from underneath the slab!" However, this is usually not true.

  1. In most cases, while the water migrates through a poured concrete wall, it sinks and comes out at the bottom of the wall. In the case of concrete blocks, the hollow cavities fill up and the highest pressure is at the bottom of the water column. This seepage makes it appear like the water is coming up from the floor-to-wall joint. The solution is usually easy – seal the walls with RadonSeal to stop the water migration.
  2. Sometimes, water building up outside the foundation seeps through the joint where the wall sits on the footing and then up through the floor-to-wall joint. The solution to this problem would be to chase the joint 1/2" deep with a hand-held grinder and fill the joint using ElastiPoxy Joint & Crack Filler Kit (to provide a flexible joint). Alternatively, you can avoid having to use a grinder and inject the joint with our Easy-Peel DIY Foundation Crack Repair Kit – more expensive but the expanding polyurethane will also seal the leaky wall-to-footing joint.
  3. In rare cases, water actually comes up from underneath the slab and at the same time, it will also seep through any cracks or expansion control joints in the floor. It may push through the pores in the concrete and in the most extreme cases, form hissing mini-geysers on the floor. The solution is installing a sump pump to relieve the hydrostatic water pressure and sealing the floor with RadonSeal Concrete Sealer.

Waterproofing Stone or Brick Foundations

Many older homes have foundations constructed of limestone, sandstone, or fieldstone. The weak link in these types of foundations is the porous, soft, and crumbling mortar. It provides an easy avenue for water seepage which gets worse and worse as the mortar deteriorates.

Stone Foundations – First remove any loose or crumbling mortar with a wire brush or a wire wheel attachment for an electric drill. Spray on RadonSeal Plus Concrete Sealer to strengthen and waterproof the old mortar. Then, if needed, repoint with new mortar. Sealing the old mortar first will prevent water from pushing off the new mortar. You can let the new mortar cure for at least three weeks and seal it also with RadonSeal.

The waterproofing seal is permanent! You cannot find a similar product in stores.

Note that RadonSeal will react inside limestone and sandstone, stopping the annoying crumbling of the surface. In case of fieldstone, you can wipe it off with a wet rag before RadonSeal dries out on the surface.

Brick Foundations – To properly waterproof clay brick walls (like Chicago brick) use LastiSeal Brick & Masonry Sealer. Like RadonSeal, LastiSeal penetrates deep into porous bricks and mortar but it cures as a plastic. The seal will never peel or crack because it does not form a surface film. It holds back hydrostatic pressure and will also strengthen and harden the bricks and mortar.

Once cured, the waterproofing seal is practically permanent (a 15-Year Waterproofing Warranty).

There is no similar product sold in stores!

Answers to Questions about Waterproofing Basements

We receive many emails from homeowners looking for answers to questions about how to solve their damp basement issues. Here is a couple of recent ones that you may relate to:

Q: "I have a damp basement wall with efflorescence and some crumbling (see picture). Since this picture was taken, the wall has mostly dried up (as the weather has gotten colder and the air dryer). Which product do you recommend I use to seal my basement wall?"

A: Prepare the concrete first by removing the efflorescence and use our RadonSeal Plus to seal the basement wall. Please take the time to read about sealing porous cinder blocks.

Q: "Will RadonSeal work on brick and mortar on a house or only for concrete/cinder block?”

A: RadonSeal can seal brick, but

Cinder block wall

Surprising Solutions That May Save You a Bundle

Leaking Water Pipes
Is your basement leaking or sump pump always running in rain or sunshine? Suspecting a spring under your basement? Call your water company first to have them check it! The water main to your curb box or the pipe to your house may be leaking, particularly if made of plastic. Usually, the serviceman will detect slight hissing in the pipe entering your basement.
Clean the Exterior Footing Drains
Footer drains, which are crucial to relieving the water pressure on your foundation may get clogged by silt or tree roots. If there is access, hire a drain cleaning contractor to clean them with by high-pressure water jetting or with an auger snake. Old clay tiles may have collapsed and just a small section may need replacement.
Clean the Floor Drains
Make sure the floor drain is not clogged. Some experts recommend getting the entire drain cleaned by a drain cleaning company on an annual basis. Make sure that the drain has a U-trap filled with water, so that it does not let in soil gas saturated with water vapor and radon gas.

How about the Usual Basement Waterproofing Methods?

Each method has its pluses and minuses. None, however, provide a solution for both basement walls and floors, and all cost much more than the using RadonSeal basement waterproofing products:

Hollow Baseboards
A plastic channel system ("interior gutters") glued around the perimeter of the floor to collect water seeping through the basement walls and route it to a sump pump. Instead of keeping water out, it works after the water has entered – a bad idea! You cannot finish the basement walls because it would trap all the moisture evaporating from the channels, causing molds and mildew. It does not do anything against water seepage through the floor. Usual cost $3,000 to $5,000.
Floor Perimeter Drainage Gap
A "floating slab" design with a wide gap (1/2" or more) around the floor in order to allow water seeping through the walls run down below the slab. A very bad concept! The walls should be built waterproof in the first place. The gap will let in tons of soil gas saturated with moisture and radon gas. Framing the walls would trap water vapor and lead to molds and mildew.
Sump Pump
Sump pumps relieve excessive water pressure by draining the gravel bed underneath the slab. Note: Not effective for leaking basement walls. Digging the pit and installing a sump pump costs around $1,000. Install an airtight cover to prevent the release of water vapor and radon into the basement. Complete reliance on a sump pump is unwise – it may fail or the power may go off. If the basement is finished, make sure to install a backup sump pump to protect your investment.
Interior Footing Drains
The perimeter of the floor has to be jack hammered, a perforated pipe laid in gravel next to the footings, and the concrete filled back in. The French drain carries water to a sump pump. Do not leave a gap next to the walls because it would let in vapor and radon. Usual cost around $6,000, including the sump pump. It will reliably drain the gravel bed underneath the slab. But if there is no gravel or it is silted up, the center of the floor may still wick water. And it will do little for seepage through basement walls.
Exterior Waterproofing
This is a big job! It requires removing landscaping, excavating down to the footers, laying new perimeter footing drains in a bed of gravel, cleaning and waterproofing the walls, protective resin boards, drainage gravel, and backfilling. Since tar coating on concrete walls cracks and breaks down, use a rubberized (polymerized) membrane waterproofing coating, or a dimple drianage board over a damproof coating (dimpled plastic sheets). Usual cost will be in the proximity of $15,000, but will do little for water seeping through the basement floor and foundation coatings are not permanent.