Water accumulation in a basement can be harmful in several ways. Water can cause structural damage, while increased moisture promotes mold.
At the same time, the basement becomes unfit for use. But waterproofing this area can solve all those issues.
How Much Does Basement Waterproofing Cost?
On average, basement waterproofing prices range from $3 to $10 per square foot. The price range is very wide because several factors can influence the final expense of waterproofing.
For instance, the job might include only basic waterproofing or involve excavation, pump installation, and other additional steps.
Exterior waterproofing is done with a special membrane or coating that prevents water from passing into the basement walls.
This waterproofing type costs between $2.80 and $6.10 per square foot. However, exterior waterproofing can involve several different methods that are priced individually:
Cement waterproofing: $5.20 per square foot
Liquid membrane: $3.30 – $5.70 per square foot
Sheet membrane: $3.32 – $6.50 per square foot
Bentonite panels: $3.50 per square foot
In addition to these methods, several additional steps can be done to ensure the best water prevention possible. These are, of course, charged separately from the basic cost.
Weeping or drain tiles can be installed for an average price of between $2,450 to $16,000. And if excavation is necessary to make the basement walls accessible, the cost for that job will depend on the size of the area that needs to be excavated.
Generally speaking, it will cost around $50 to excavate a cubic yard. A linear foot of excavation will be priced at $90 to $260, but most contractors will have a fixed minimum price that usually won’t go below $2,900.
Finally, it should be noted that a basement can be waterproofed from the inside, which eliminates the extra cost of excavation. The three basic interior waterproofing materials are concrete, crystalline, and elastomer.
A square foot of these will cost $5.20, $5.50, and $4.10 respectively when installed.
Internal waterproofing also comes with some specific additions, too.
Different sealers – silicate and epoxy in particular – can be applied for increased durability and stability. Both silicate and epoxy sealers will cost from $3.10 to $6.90 per square foot.
Waterproof paint will be the next addition, with a price of up to $200 for a five-gallon pack. For reference, a single gallon will be sufficient for about 120 square feet.
In total, basement waterproofing can cost from a mere $260 to over $21,000, depending on the particular expenses. The average national price for this job ranges from $2,000 to $6,300.
Estimate the cost of a full basement remodel
How Is Basement Waterproofing Done?
Planning and preparation are needed to waterproof a basement properly. It’s crucial to get an accurate determination of the type of waterproofing that needs to be done, as well as any additional work.
Exterior waterproofing jobs usually start with excavation. This includes digging around the basement perimeter until the foundation is reached. Once the excavation is completed, the outer wall will need to be cleaned thoroughly.
This is the best time to look for potential cracks in the wall where water might pass through. If such cracks exist, they’ll need to be sealed.
The most common sealant for the outer basement wall comes in the form of hydraulic cement coating. This material expands, filling in both obvious and hidden cracks.
Additionally, all exterior walls will require another sealant based on non-hydraulic cement. This sealant is designed to harden and close the pores of the concrete. The material will cover and close any cracks that were too small for the previous layer to fix.
With all the preparation and fixes taken care of, it’s now time to apply a membrane. As mentioned, this membrane can be liquid or sheet. The membranes are applied to the wall by spraying or troweling.
This layer of waterproofing material has special traits that make it ideal for the job. For instance, waterproofing membranes are flexible enough to close any new cracks if they occur.
When the membrane is installed, the drainage mat will follow. This is an additional layer meant to isolate moisture and transport it to the drain. For that reason, the mat should match the foundation depth precisely.
Finally, a weeping tile or French drain will usually be installed. It’s worth noting that the weeping tile is also a type of pipe, despite its name.
These pipes should be located at the footing base to allow for additional slow drainage below the floor. It’s best to have cleanouts installed so that the pipe can be maintained without issues.
Interior basement waterproofing doesn’t require excavation like the exterior method. The coating process is the same as with an exterior basement wall, with additional layers designed for interior use.
After the coating, silicate sealers can be applied to ensure the walls remain watertight.
Next, potential cracks can be covered with epoxy. This layer will also make the previous seals more durable. The final layers will include a vapor barrier and waterproof paint.
The entire area needs to be prepared and cleaned thoroughly before the paint can be applied. The best paint is usually acrylic, which is thicker than the regular variant. This type of paint adheres tightly to the wall.
Besides providing an extra layer of water protection, the paint can also serve as a warning system. If there are issues with the exterior waterproofing, they’ll cause the paint to break down, indicating the problem.
Interior waterproofing will also require water drainage. This calls for installing polyethylene pipes into the walls. The pipes will then need to be connected to a sump pump which will pull the accumulated water outside.
It’s not unusual to build a second interior wall to hide the drainage pipes.
The drainage system is completed with the installation of a sump pump. A backup pump could potentially be installed if there’s a fear of flooding.
Interior waterproofing is best done in combination with exterior waterproofing. This way, the basement gets double protection that will almost certainly keep the water out.
Did you know? Basements aren’t widely accepted throughout the U.S. In fact, houses in some Southern states, such as Florida or Texas, don’t feature basements at all.
This aversion to basements is a result of specific soil types prevalent in these states. For instance, clay land, which is abundant in Texas, is prone to swelling and shrinking.
These movements can put additional pressure on the walls and could jeopardize the foundation. Another example might be land that has plenty of near-surface water.
Pros and Cons of Different Basement Waterproofing Methods
While it might seem like all the aforementioned methods of basement waterproofing bring only benefits, the truth is that each system comes with certain negative issues.
With interior waterproofing, the primary purpose is to divert the water towards the pump which takes care of the drainage.
Of course, the sealing layers play a crucial role here in preventing new water from coming in at a rate that would overwhelm the drainage system.
Pros of interior basement waterproofing are that the method is exceptionally effective in terms of alleviating the hydrostatic pressure from the basement base. This is also a relatively inexpensive technique.
However, the cons of interior waterproofing highly outweigh the pros.
Firstly, interior waterproofing alone doesn’t resolve the issue of water leakage. While drainage can be highly effective, the water will likely still find its way into the basement. Also, this method doesn’t contribute to getting rid of excessive humidity.
In other words, a basement with only interior waterproofing will deal with some of the consequences, but not entirely.
The root cause of basement flooding will still be unaddressed.
Exterior waterproofing is best done by total excavation. This provides unhindered access to the exterior basement foundation wall. The wall is then isolated and drainage installed to keep water from passing through.
On the pros side, exterior waterproofing ends the problem of water leaking inside. With the water effectively prevented from getting into the basement, humidity stops being an issue as well.
In addition, exterior drainage will keep the basement and the entire area around it relatively dry.
The cons are mainly tied to the work process around exterior waterproofing, particularly excavation.
Excavating can be very labor-intensive, requiring you to factor in the time necessary to complete the project as well as the costs.
Plus, the nearby landscape will be damaged by the excavation. This doesn’t represent only an aesthetic setback, though. The ruined landscape will need to be remodeled, which will cause even more expenses in time and money.
Finally, there’s a combined method of interior and exterior waterproofing. This method also involves excavation, wall repairs, and sealing. Furthermore, drainage is installed inside and outside of the basement.
However, this combined method should resolve every problem related to moisture and water and significantly reduce further exposure to similar issues.
Combined waterproofing also creates superior drainage and ensures there’s little to no further damage to the basement structure.
One of the major cons of this method is its price, which includes interior and exterior prices combined. The cost alone will deter many homeowners.
The other issue related to the combined method is the same as what appears in exterior waterproofing. It has to do with excavation and the destructive effect it has on the surrounding landscape.
Is Basement Waterproofing Worth It?
Basement waterproofing resolves several issues that can quickly become quite severe. For starters, increased humidity is unhealthy and can lead to mold expansion.
With proper waterproofing, the risks of humidity and water-related hazards are removed. And that’s not even the most significant benefit of waterproofing.
When the basement is made waterproof, the home’s foundation is effectively reinforced. And it should go without saying that the foundation is a crucial part of every building.
When all this is taken into consideration, waterproofing will certainly be worth it, no matter the cost.
Is Basement Waterproofing Tax Deductible?
In its basic form, waterproofing is considered a type of home repair, which makes it ineligible for a tax deduction.
However, there are ways to make the project tax-deductible if specific criteria are met and the circumstances are right. Naturally, it’s best to consult a tax expert to ensure that the deduction applies.
Circumstances that may lead to a tax reduction include:
Incorporating the waterproofing work into a home remodeling project. These projects are eligible for tax reductions, especially when the remodeling is done to accommodate a household member with special needs.
Turning your basement into a home office. Tax deductions apply when you’re repurposing your home space as an office or storage space. However, it’s worth noting that, in this case, the space must be used for the intended purpose exclusively.
Is Basement Waterproofing Covered by Insurance?
Waterproofing usually doesn’t have insurance coverage. If flooding happens in the basement, the insurance company will likely cover the clean-up.
Then the rest of the coverage will depend on the cause. If there was an internal cause, such as a broken appliance or pipe, the resulting damage will be covered by the policy.
The same goes for a tub or sink that has overflown. However, external sources won’t be subject to insurance coverage.
In other words, if the cause is a harsh storm, groundwater, or a nearby flooded body of water, the policy won’t apply.
Even specific insurance against floods won’t ensure coverage in the case of floods caused by groundwater.
This is because insurance companies view such issues as the result of poor maintenance.
Does Basement Waterproofing Add Value?
Since basement waterproofing is a major structural and functional home improvement, it adds significant value to the home.
In fact, the added value can be equal to up to 50% of the original investment.
The Most Inexpensive Waterproofing Techniques
Waterproofing can be quite an expensive project, making some homeowners shy away from the daunting task. Luckily, there are certain waterproofing techniques that can help you get the project done even on a tight budget.
The first low-budget method is applicable only in basements with concrete foundations. This foundation type is quite common, as poured concrete has been a standard for home foundations since the ’80s.
Most of the leaks that appear in such foundations can be repaired with relative ease. All you need to do is inject the leaks with polyurethane.
This material is designed to seal the cracks. Even better, the polyurethane will pass through the entire crack, reaching the soil on the outside.
However, if the foundation is made of concrete blocks or cinderblocks, the injection won’t represent a viable solution.
Instead, this type of foundation can be waterproofed with an interior drain system.
The interior system is relatively inexpensive but highly effective. It doesn’t have to represent an option for waterproofing on a budget but can also solve several other problems.
For instance, interior systems can come in handy if exterior waterproofing with excavation isn’t possible or would jeopardize existing structures of the landscape.
Another case where this system could be useful is when the flooding isn’t due to external sources beyond the basement walls.
If the cause is in a water table that’s rising beneath the floor slab, internal waterproofing might be the better solution.
Waterproofing vs. Damp Proofing
People often don’t know the difference between waterproofing and damp proofing and even use the two terms interchangeably. However, the difference is quite distinct.
Simply put, waterproofing prevents water from getting in, as well as minimizes the chances of moisture building up. Damp proofing is only intended for counteracting the moisture from the soil.
The conditions upon which waterproofing or damp proofing is deemed necessary are also different.
Waterproofing is usually required in specific areas where the water table is particularly high, or the water conditions are otherwise severe.
On the other hand, damp proofing is necessary for nearly all foundation walls made of concrete or masonry. This, naturally, includes basement walls.
Waterproofing is done by several techniques that usually require distinct steps. Damp proofing is a relatively straightforward process.
It is essentially an asphalt-based coating that can be applied by hand or can be sprayed on the wall.
In the modern day, damp proofing isn’t recommended quite as often as it was previously. That doesn’t mean that it’s not a useful or acceptable treatment. Most often, the problem is that damp proofing simply isn’t a sufficiently effective solution.
This technique doesn’t provide a way to seal particularly massive holes or cracks. Of course, waterproofing is extremely effective because it’s intended to remove any water-related issues.
Waterproofing includes a complete drainage system, both on the surface and installed into the foundations. It can make damp proofing unnecessary, but the two systems can also be extra effective when combined.
Finding the Best Basement Waterproofing Solution
There are several available waterproofing options that serve specific purposes and come with distinct advantages and downsides.
The choice of the right waterproofing system will depend on the circumstances and the level of risk presented by excessive water flow.
While complete basement waterproofing can be quite expensive, especially for larger surface areas, certain low-budget options exist that can be used as reliable, yet temporary, solutions.
If possible, it would be best to waterproof the basement using the combined internal and external methods. If not, the needs and situation will dictate the necessary method of choice.