AVERAGE COST TO
WATERPROOF A
BASEMENT
Over the lifetime of a house, 98% of basements will – at some point – experience problems with water. Water is so powerful, and basements are so vulnerable, that it is inevitable, eventually, that water will make its presence felt unless you take action.
Waterproofing your basement is one way that you can ensure that your basement stays dry (at least from water entering from outside your home).
There are four main reasons why you should waterproof your basement:
It prevents your basement from becoming flooded during storms
It ensures everything in your basement remains dry – so you can use
your basement as a functional space
It reduces all forms of moisture in your basement, minimizing the risk of mold and mildew
It protects the structure of the house from water
THE OVERALL COST
The national average cost of waterproofing a basement is $4,188. The low
end of the range is $250, and the high end is $20,000. The typical cost range
is between $1,920 and $6,320.
PRICE PER SQUARE FOOT
On average, the price for basement waterproofing is between
$3 and $9 per square foot, divided between labor and materials.
| SQUARE FEET | COST |
|---|---|
| 1 | $3 - $9 |
| 10 | $30 - $90 |
| 100 | $300 - $900 |
| 500 | $1,500 - $4,500 |
| 1,000 | $3,000 - $9,000 |
Basement Waterproofing Calculator
Calculate how much you’ll pay for basement waterproofing based on the square footage of the area.
CAUSES OF WATER IN A BASEMENT
The first step is to identify the cause of water in your basement. Water in the basement usually comes from a handful of sources. Understanding what needs to be repaired will give you a rough estimate of the costs involved.
| CAUSE | PROBLEM | COST OF REPAIR |
|---|---|---|
| WINDOW WELL | If water does not drain from your window wells, the pressure will build up (particularly during times of heavy rain) and then seep into your basement. To repair, a contractor will install a window well drain. | $500 - $2,000 |
| FLOOR CRACKS | A crack in the floor makes it easy for water to enter your basement. Water pressure will also increase the size of the crack, meaning catching the problem early is key. | $620 - $850 |
| COVE JOINT | The cove joint is the gap where the wall meets the floor in your basement. This is an extremely common source of water seepage. | $200 - $300 |
| PIPES | Older pipes are always susceptible to bursting or leaking, particularly during times of colder weather. | $200 - $300 |
| SEWER | A backup in the sewer system will lead to water leaking into your home - usually into the basement. | $100 - $300 |
Note: The prices listed above do not include the cost of cleanup as a result of any water flooding. For more detailed information on flooding costs, please see our guide on the average cost of basement flooding.
DAMP PROOFING
If your basement is less prone to flooding, and more prone to high humidity, then damp proofing is potentially a better option.
Damp proofing a basement costs, on average, $3-$6 per square foot – less if you do not need to excavate.
EXTERIOR WATERPROOFING
Exterior waterproofing involves sealing the basement from the outside, so water
does not enter the structure of your home. The average cost of this is between
$1,500 to $4,250.
Exterior
Excavation
In order to waterproof the exterior of your home, you will need
to excavate down to the base of your foundation. This will allow
the sealant or tiling system to be installed. Generally, the costs
for excavation are between $100 and $250 per linear foot.
Most contractors will have a minimum call-out charge of $3,000
for excavation, which involves the use of an excavator and a
crew to operate it.
Sealing
The most common way of waterproofing your basement is to
seal it from the outside. This has the following benefits:
- Prevents water from permeating the structure of your home
- Protects wiring, paint, wood and so on in the walls of your home
- Diminishes the chances of mold and mildew
The type of sealant used is dependent on the soil and climate conditions around your
home. In most cases, you will need a professional to help you install the sealant, so
prices below reflect the cost of both the sealant and the installation.
| TYPES OF SEALANT | PROS | CONS | COST PER SQ. FOOT |
|---|---|---|---|
| CEMENTITIOUS |
|
| $5.25 |
| LIQUID MEMBRANE |
|
| $3.34 - $5.76 |
| SHEET MEMBRANE |
|
| $3.35 - $6.52 |
| SODIUM BENTONITE PANELS |
|
| $3.53 |
Weeping
Tiles
Despite the name, weeping tiles are not tiles; they are French drain systems installed around the perimeter of your home. They prevent water from pooling around the structure of your house. Most commonly, weeping tiles are installed inside your basement, although there are benefits to installing them outside your home, usually in conjunction with one of the sealant systems outlined above.
The advantages of a weeping tile system are:
An extremely
effective long-term
solution
Does not damage the landscaping around your home (as they are buried)
Removes
hydrostatic
pressure
Increases the
longevity of
basement
sealing
Increases the
value of your
home
On average, installing weeping tiles will cost between $2,500 and $15,000.
They are an expensive option, but they usually only need to be installed once over the lifetime of a home. Also, as mentioned above, the price can usually be recouped through the increase in the value of your home.
Regrading
Yard
If you decide against a weeping tile system, a more budget-friendly option may be to regrade your yard to slope it away from your home. Water will then runoff away from your house, relieving pressure on your foundation wall and reducing the chance of foundation cracks. Again, you can do this in conjunction with a basement sealant.
The average cost of regrading a yard is $1,528, with a range of between $100 and $4,500.
INTERIOR WATERPROOFING
Because the cost of excavation is not needed, the cost of waterproofing a basement
from the inside is often far cheaper. The downside is that water can still enter the
walls of your home. However, if you can mitigate this in other ways (French drain
systems, yard regarding) this is an excellent way to protect your home.
SEALANT
| Type of sealant | COST per sq. foot |
|---|---|
| Concrete | $5.25 |
| Crystalline | $5.53 |
| Elastomeric | $4.13 |
SILICATE SEALERS
Applying a silicate sealer to the concrete of your basement wall is the most cost-effective way of waterproofing. A single layer of silicate coating costs between $3 and $7 per square foot (including labor) although you will need at least two coats.
Once you have painted the silicate sealer you can also add an epoxy sealer to increase the effectiveness. This costs between $3 and $7 per square foot.
WATERPROOF PAINT
Waterproof paint is a form of acrylic paint that bonds
closely to the wall, providing a watertight seal. The cost
for this is between $0.61 and $0.87 per square foot (the
lower end of the range represents doing the painting
yourself).
However, you will need to do fairly extensive prep work
to your wall in advance of painting. In addition, if the
exterior of your home has not been properly
waterproofed, then acrylic paints will not hold back the
deluge – it will become cracked very quickly in the face
of large amounts of water.
WATERPROOF A CRAWL SPACE
Crawl spaces are often magnets for moisture and dampness. The cost of waterproofing ranges from $2,000 to $10,000 depending on:
- The size of the crawl space
- The amount of water already there
- The condition of the space
- Existing waterproofing solutions
The costs of waterproofing a crawl
space are driven up by the fact that
they are difficult to access.
Vapor barrier costs between $0.15 and $0.50 per square foot and usually lasts for 20 years.
You should use a professional to install a vapor barrier so as to ensure there are no gaps.
EPOXY INJECTION
If you have a small crack in the wall, a short-term solution will be to inject it with epoxy to fill in space. Any crack smaller than an inch will be eligible for this treatment.
The cost for this is between $200 and $500 and usually takes less than an hour – with a further 5 hours to dry.
It is important to note, however, that this is only a
temporary solution to the problem, particularly if you live in an area that experiences regular freezing and thawing.
Although water in your basement is almost inevitable at some point in your home’s life, it doesn’t mean there’s nothing you can do about it. Indeed, it’s often better to act and spend a little money in the short-term, before you’re forced to spend a lot of money. From a financial perspective, a robust, long-term solution will be an asset to your home – so don’t think about waterproofing as a cost, but as an investment.