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What to Do When a Home Inspection Reveals a Wet Basement

Tuesday, July 6th by Kristina McGovern


Did you put an offer on a home and then find out the basement is leaky or there's been past flooding? Here's a rundown of what a wet basement means and your options for keeping the home dry.

A bucket and broom next to a water puddle on a basement floor

Basements are prone to water intrusion because they're built below-grade. Damp or wet basements can lead to mold and mildew, rotted wood, and damage to stored items.

The last thing you as a homebuyer wants is a home inspection that reveals a problem with water in the basement.

Whether it's a basement that's damp at certain times of the year, a basement that leaks every time it rains, or a basement that's had flooding, you have good reason to worry. Water intrusion and moisture can lead to mold growth, wood rot, and structural damage.

While not ideal, finding evidence of a wet basement doesn't mean all hope of buying your dream home is lost. If you're dealing with leaky foundation walls or water coming up through the basement floor, taking the right measures now to protect the home from continued or future water intrusion can save you a lot of money in the long run.

This guide can help you understand why wet basements happen and effective solutions to waterproof the basement.

Check the disclosure and ask questions

Many states have explicit disclosure requirements around water intrusion and water damage in the basement. Some states have a caveat emptor for real estate transactions, which means the seller isn't required to disclose any defects with the property, such as a wet basement.

Keep in mind that if you're buying a house in a non-disclosure state, sellers are required to truthfully answer relevant questions from the buyer, such as those about past water problems in the basement. If the home has an existing basement waterproofing system, including a sump pump and drainage pipes, be sure to ask if they have receipts or records for the work that was done or a warranty for the system.

Check the slope of the lawn

Depending on where and how the house is situated on the property, surface water may run toward the house instead of away from it. Without a proper slope, water can pool near the foundation and leak or seep into the basement.

The solution might be as simple as regrading or pitching the dirt away from the house. The ground should slope away from the home at least a half-inch per foot for 10 feet (Building America Solution Center).

Foundation plantings should be drought tolerant. Plants that require a lot of water shouldn't be planted along the foundation to avoid excess water that often seeps into the foundation.

Take a look at the gutters and downspouts

Rain gutters and downspouts should channel water away from your home's foundation. This reduces the risks of a flooded basement, damaged siding, erosion, and damage to your landscaping.

What to Do When a Home Inspection Reveals a Wet Basement - Image 2

Downspouts that are too short cause water to pool near the foundation.

However, some homes don't have rain gutters, especially those in dry climates. Other homes have gutters with trees growing out of them! Both of these scenarios can lead to water pooling near the foundation and water intrusion.

Gutters should be kept free of leaves and debris so they can properly drain water away from your home. This means cleaning the gutters at least twice a year or installing high-quality gutter guards to avoid clogging.

Traditional sectional gutters come in sections that are pieced together and sealed at the seams to prevent leakage. Seamless gutters are gaining in popularity due to their seam-free design that reduces the likelihood of leaks. The Gutter Shutter system is seamless and has built-in gutter guards to prevent leakage and clogs, so there's no need to install two separate products. This system is guaranteed to never clog, sag, or pull away from the house.

Downspout extensions can be installed to prevent runoff from pooling around the foundation. They should extend at least three feet away from the home. While extending the downspouts is a quick and cost-effective solution, sometimes a full basement waterproofing system is necessary to solve the problem for good.

Pay attention to musty smells

If you noticed an unpleasant, musty odor in the basement, this could be a sign of mold or mildew. A musty smell is more common during periods of damp and humid weather. When moisture builds up in the basement, it can quickly lead to mold growth. Mold spores can trigger allergy symptoms, cause staining, and destroy wood studs and floor joists, drywall, and carpets.

When there's a musty smell or visible mold in the basement, the first step is to look for leaks in the basement that can lead to mold and mildew growth. This includes "sweating" pipes, a leaky basement window, water leaking through a crack in the basement wall, or seepage through the foundation. Minor leaks or water seepage can sometimes be solved by directing water away from the foundation, while a persistently damp or wet basement problem typically requires installing a drainage system.

If your basement is still damp after leaks in the basement have been fixed, the problem could be the humidity. An inspector might use a hygrometer to test the basement's humidity level. Mold thrives in humidity that's 60 percent or higher.

A dehumidifier can be installed to control humidity that can be making your basement damp and musty. When choosing a dehumidifier for your basement, pay attention to the capacity and look for one that's equipped to drain or pump out collected water automatically - otherwise, you'll need to empty a bucket. During humid weather, this could mean emptying a bucket twice a day! The SaniDry Sedona is an efficient, compact solution to remove excess moisture and filter the air at the same time.

Look for cracks in the walls and foundation

Water that pools by the foundation is always a problem, especially where there's clay soil underneath. Soils with high clay content swell when wet. This exerts pressure on the exterior foundation walls, increasing the risk of the foundation cracking and shifting. Frost heave during freeze-thaw cycles can also lead to foundation damage.

If there are wide cracks or several cracks in the basement walls, you may need to install an interior drainage system.

Waterproof paint and membranes are two common methods for waterproofing basement walls. They are designed to prevent outside water and moisture from seeping through the basement walls. Unfortunately, these aren't long-term solutions, as they allow hydrostatic pressure to build up against the foundation, so even a small gap can eventually result in significant leakage.

An interior basement drain and sump pump system works with water pressure instead of against it. An interior waterproofing system captures groundwater before it reaches your basement floor and a sump pump pumps it out of your house.

Check the condition of an existing sump pump and drainage system

If the home you're buying has a sump pump and drainage system, this could be good news for you, since this means any previous water intrusion was likely addressed. However, you should consider the quality and effectiveness of the existing system.

Homes built in areas with a high water table typically have underground pipes, known as French drains, to prevent water intrusion. However, exterior drainage systems are expensive to install after the home is built and they are prone to clogging from silt, roots, and even pests. Exterior French drains should be cleaned out at least once a year to ensure proper drainage. A professional can inspect your French drain to check for buildup or debris that could lead to clogging.

Sump pump and dehumidifier system installed a basement

A high-quality sump pump and dehumidifier system keeps out water and moisture that causes rot, mold, and unhealthy indoor air.

Interior drainage systems are a practical solution for fixing basement water problems in existing homes. An interior basement drain collects groundwater from below the basement floor and water that seeps in along the basement walls and floor and directs this water to a sump pump that pumps it out of your basement and away from your foundation. The design and installation of the WaterGuard drainage system make it nearly invisible - a major advantage if you're thinking about finishing the basement.

A high-quality sump pump can be invaluable during flooding or periods of heavy rain. Depending on the type of sump pump you have, when water reaches a certain level in the sump pit or on the basement floor, the pump turns on and pumps the water outside of your home where it can drain away from the foundation.

A sump pump can't work without electricity, so consider adding a battery-powered pump. When there's a power outage, the battery backup pump will take over for the primary pump to pump the water out of your basement.

The TripleSafe Sump Pump System includes two submersible primary pumps and a built-in battery-powered backup pump for a cost-effective solution that provides maximum protection from most flooding hazards.

Keep an eye out for band-aid solutions

Waterproofing paint is a popular DIY option for homeowners looking to stop water seepage through their concrete basement walls. Designed to create a water barrier, waterproof paint is heavier than the paint you would use on the walls in your upstairs living space. Depending on the severity of the seepage problem, waterproofing paint may provide a temporary fix, but you shouldn't expect a permanent solution, especially if there are large cracks in your foundation.

Paint or other remodeling work done in the basement could be covering up cracks or moisture stains. Err on the side of caution and ask the seller about any past issues with water in the basement, especially if there's a finished basement.

Many inspectors use a moisture meter to detect differences in the moisture level throughout the home. A higher moisture reading in the basement could indicate water intrusion that you don't see.

Be aware of the depth of the water table

A high water table is common in low-lying areas and in soils with high clay content. High water tables could be seasonal or high all the time.

The water table rises when there's more water in the soil, but not enough water draining away, such as during prolonged periods of heavy rainfall. This is especially common during the late winter and early spring when the snow starts to melt and spring rain adds more water. The surface water seeps into the ground and the water table rises. With nowhere for the water to go, it finds its way into the basement.

When the water table rises above the level of the basement floor, this often leads to water coming up through the floor. Pooling water in your yard can be caused by poor drainage, but it's also common when the water table is high.

This article from the United States Geological Survey includes helpful resources to help you find out the depth of the water table in your area. You might also consider asking a neighbor or the local county extension office where you're buying the home about the specific soil and water table in the area.

Ask the seller about a warranty

If the basement was waterproofed, ask the seller if they have a warranty for the work that was done. That way, if any future issues do arise, you can contact the waterproofing company who installed the system.

The local waterproofing contractors who install Basement Systems products offer a lifetime warranty that's transferable to the next homeowner. The warranty applies to interior drainage systems. Many of these basement waterproofing companies also offer their own labor warranty.

Know what is and isn't covered by insurance

If you're worried about future water incidents, you'll want to know what's covered by your homeowner's insurance policy. Coverage of basement water damage depends on what caused the damage.

A homeowner's policy will typically cover most structural damage caused by "sudden and accidental" events that happen inside the house, such as a burst pipe or broken washing machine. What's not usually covered is damage from flooding caused by a rising water table due to a hurricane, rainstorm, melting snow, or another weather event. Be sure to read your policy and call your agent or insurance company if you don't understand your exact coverage details.

Separate flood insurance can be purchased from the National Flood Insurance Program. Your mortgage lender might require flood insurance if the home you're buying is located in a flood-prone area. Check with your insurance agent for help purchasing a flood policy.

Don't assume all wet basements are created equal

Homeowners often avoid calling a contractor about the water in the basement because they're afraid of how much it will cost to fix the problem. No two houses are the same. Sometimes solving a wet basement problem is as simple as repairing a small crack or extending the downspouts. A dry basement offers many benefits, including storage space and the potential to use the area as additional living space or a basement apartment that you can rent out.

A basement waterproofing professional can tell the difference between minor seepage and a major water problem. Most Basement Systems contractors offer free estimates, so it won't cost you anything to find out the extent of your problem.

Any wet basement can be fixed with the right combination of solutions. Contact your local Basement Systems contractor to schedule a free, on-site waterproofing estimate.

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