Methods Of Exterior Basement Waterproofing 

Exterior basement waterproofing is often associated with digging. Though, it is a more extended process involving excavation work around the entire foundation area which is subject to water penetration. Sometimes, the company which is doing waterproofing work needs a locate. This is a special permit to ensure that all the jobs will be carried out carefully and professionally. The reputable company can offer various waterproofing options to seal the foundation. They may include installing an external waterproofing membrane, weeping tiles, or cementitious solutions. All of them are used to redirect any excessive water or dampness from your foundation.

Waterproofing or Damp Proofing

When your basement and foundation suffer from extended water flow or moisture, you are commonly offered waterproofing or damp-proofing. Very often, you do not see much difference in these terms because both procedures are meant to reduce the penetration of water through the materials your house is built from. However, there are some important differences to discuss and understand. If your concern is excessive moisture in the basement, just have a quick look at the difference between damp-proofing and waterproofing to know what to expect.

Waterproofing involves the procedure of blocking any water from penetrating into the materia l(water vapor, flooding caused by hydrostatic pressure, or even soil moisture).

Damp-proofing is related to water vapor and soil moisture only. It cannot control flooding water. That is why damp-proofing may turn out to be insufficient in the areas with high water tables or extensive water in the soil. Damp-proofing can be used here only under certain specific conditions. For instance, you may want to seal the finished footing from the grade to the top. In this case, the procedure will involve a sealant that is applied to the outer part of the foundation walls. That can prevent soil water vapor from penetrating into the waterproofing material of the construction.


The basement and foundation walls are most often subject to water seeping in because they are in close contact with the soil. That is why they should be sealed with concrete waterproofing sealer. However, keep in mind that even if concrete does not absorb water, it may allow moisture penetration.  The concrete waterproofer helps make your home free of mildew and humidity indoors.  So, concrete coating can differ according to the conditions. Some of the most widely used ones for masonry and concrete walls are described below. Excavation and backfill jobs are not considered here.


Cement waterproofing is usually used in dry climatic conditions. This solution has many benefits. The cement coating is thick and quite durable. It is easy to apply and it provides a smooth surface that can be painted. This option works very well for crawl space sealing or patching cracks. However, the cement as a material is not flexible, so it is very ineffective when applied for cracking or joint movements. This is its significant drawback.

Foundation Waterproofing Membrane

The exterior of your foundation can be coated with a special membrane. It is meant to block all the excessive water before it approaches the foundation wall. This way, the damage from the water caused to thee foundation is diminished. Therefore, your personal belongings or other parts of the house will not suffer at all. Your crawlspace or basement can be used for storage or for other family’s needs.


Bentonite clay or sodium bentonite is a material that effectively absorbs water. When applied to the exterior foundation all, it expands and fills in the cracks. The seal is formed which prevents water penetration. The waterproofing shield is usually made of this clay and corrugated cardboard. This coating is very effective if installed properly. If not, it should be completel redone to carry out its waterproofing tasks.

Weeping Tiles

The common drainage system which is called weeping tiles should be installed around the house foundation close to the exterior part of footing at the base of the foundation walls. Very often, this system is also called drain tile or drainage tile. It works to block and redirect water which usually accumulates at the footing (or at the foundation base). This excessive water is drained to the storm sewer located in the street or into a sump pump liner. The latter is normally located underneath the floor of your basement.

When water stays for long at the foundation base, something should be done about it. The foundation is usually made of concrete, concrete block, or cinderblock and these materials are rather porous. They tend to absorb water very fast and that results in the situation when the basement foundation wall collects all the water around depending on the water table height. In the end, your foundation turns out to bathe in the puddle of water for a long time if this water is not drained immediately. The outcomes are obvious – the base of the foundation is damaged and you get the wet basement which is occasionally flooded.

Weeping tiles are specifically meant to discharge and redirect the underground water. In fact, this system does not look like tiles. It consists of 4-inch porous pipes. However, the name dates back to the time when tiles made of terracotta were used in place of draining pipes. Modern weeping tiles are made of plastic. They have weep holes or slits for redirecting water you’re your home foundation.


Exterior basement waterproofing turns out to be a very complicated procedure. The dirt is dug out of the basement foundation walls, first. Then, a moisture barrier is applied in the form of a special dimple board that makes up a shield to excessive water and redirects it from the walls. The complete foundation excavation is used when you want to install a waterproofing system made from bentonite. Such techniques are rather costly. So, you can also consider interior drainage or sump pump system installation that is more affordable and, very often, much more efficient.

Thinking about calling a basement waterproofing contractor? Find the best exterior basement waterproofing company near me near you on Google Map- see all Tornado Plumbing & Drains locations open now.

External Waterproofing Systems


Priming is the first step in many waterproofing procedures and techniques. A special spray is applied to the external side of the foundation walls. The spray narrows the pores in the masonry and creates a smooth surface that is water-repellent. Primers can also bond with waterproofing layers chemically. That is why they are widely used at the initial waterproofing stage.

Primary Waterproofing

When a waterproofing material is applied directly to the foundation wall from the outside, this procedure is called primary waterproofing. Radon protection is also necessary here. The coating that consists of some waterproofing compounds has sufficient compression strength and does not allow water penetration even under the most aggressive pressure.

Secondary Waterproofing – External Membranes

The second step is the membrane installation. It serves as a protective coating for primary waterproofing. It works as an effective drainage system and a tool to relieve hydrostatic pressure that affects the building foundation. This membrane is also very efficient during the backfilling procedure to help settle the backfill properly.


Land Drains and French Drains

Land drains are mostly used in waterlogged areas. Because of heavy rainfalls or the type of soil, water cannot flow away. The soil becomes saturated and it does not accept any more water. So, there is a need to allow this excessive moisture to flow freely into a special pipe and further on to the designated point of its disposal. The pipe used for land drains has perforations in it and a thick layer of loose aggregate placed around. The water flows through this aggregate into the tiny holes in the pipe. The land drain pipe has to be installed with a gentle gradient to let the water move smoothly through it. Shingles are usually used as an aggregate and owing to them, the water can flow clearly in the certain direction and it does not reach the saturated soil to cause flooding.

The basements waterproofing services also involve an exterior French drain. This process means digging out a ditch along the perimeter of the foundation. The ditch is usually excavated underneath the footer and gradually directed to the surface. The procedure of the exterior French drain installation requires the preliminary removal of all the patios, shrubs, porches, sidewalks, and other obstacles located along the foundation. It means that additional expenses are needed. That is why installing inside French drains seems to be more preferable to many people.

Sump and Pump

If you want to keep your basement environment dry, you should have a reliable waterproofing system installed within it. This system is called sump and pump. It is meant to remove all the ground water from the basement foundation walls including the moisture collected by cavity drain membranes. Such a sump and pump system is quite reliable. Homeowners are likely to be sure about the effective protection of their property against flooding and other unexpected and harsh weather conditions.

Search also: What is a dry sump pump?

Exterior Foundation Waterproofing Materials

  • Henry Blueskin® WP 200 Waterproofing Membrane – 36″ x 66.7″
  • Protecto Wrap Jiffy Seal® Ice and Water Guard HT 36″ x 66′
  • TREMproof® 250GC Roller Grade Membrane

Basement Leak Repair

The condensation is a common cause of leaks in your basement. It is better to insulate the outside surface of the walls because this allows for condensation prevention. If you live in a cold climate, it makes sense to insulate the walls of the basement to save warmth.  This will also lower your heat bills. Though, never use the interior insulation of the walls if the excess water seeps from the outside. This may lead to a mold problem in the near future.

Foundation Leak Repair 

Examine the surface of your basement’s walls and floors for any cracks or holes. They should be plugged and covered. It will not solve the problem completely but can substantially reduce it. You can use hydraulic cement for doing this repair. Patch all the holes in the walls or flooring with this material. It can withstand the water and moisture very well. It can expand when applied so it seals the hole reliably. You can utilize an angle grinder together with a special disc meant for masonry cutting or just a  as the main tools for this job. You can also utilize a diamond blade here to make the ‘V’-like shape of the crack or hole in the wall. Such a shape is directed with the small part of the ‘V’ onto the wall surface. It is done for more tough and durable sealing. Before you start mixing and using the hydraulic cement, try to follow all the instructions on the package to avoid mistakes.

Common Basement Problems

  • damp cold floors
  • water puddles
  • moisture problems: mold and mildew, efflorescence, musty smell
  • wet drywall 
  • dampness
  • cracks 
  • basement condensation
  • high indoor humidity
      Learn All basement problems

    Exterior Basement Waterproofing price

    Guide to Exterior Basement Waterproofing Cost & Estimates in Toronto & GTA, Canada

    Exterior Basement Waterproofing cost (near me) 

    The costs vary. The nature of the problem, the size of the basement, whether one or all walls need to be waterproofed, are only a few of the factors working into the cost assessment. The costs of waterproofing basement from outside includes costs of planning, preparation, sealing the foundation, waterproofing walls with cement, installing a sump pump or perimeter drain, diverting downspout runoff away from the foundation, and an epoxy injection to repair cracks.

    Average cost  is about $0000 – $0000 (included repairing defects, waterproofing walls)

    • Waterproofing or Damp Proofing –
    • Sealing –
    • Cementitious –
    • Foundation Membrane –
    • Bentonite Clay –
    • Weeping Tiles –
    • Excavation –

    External French Drain cost

    An exterior french drain is easier and cheaper to install, then interior: at $00 to $00 per linear foot or $0,000 to $0,000.

    Exterior basement waterproofing average cost

    The average cost to waterproof a basement is $0,000 to $0,000, or between $0 and $0 per square foot for materials and labor.

    How we work

    Tornado Plumbing & Drains is Professional Exterior Waterproofing Company for Commercial or Residential  Construction. Here are three reasons to call us:

    • Experience: Coatings the foundation of your home or cementitious is no easy task: it takes years of expertise to be able to perform safe and enduring quality repairs. Because waterproofing are an important investment, hiring an experienced waterproofing company is essential.
    • Efficiency: Tornado Plumbing & Drains understands, no matter how big your problem is, it needs to be done as soon as possible, so you can go about your daily business.
    • Licensing: When you enlist the services of a reliable waterproofing company, you can rest assured knowing a licensed contractor who has extensive knowledge will perform the work. Tornado Plumbing & Drains is insured and fully licensed, guaranteeing you receive the best services possible, as well as ensuring you won’t be held liable for any on-the-job accidents.


    – phone number: (647) 784-8448

    – address: 45 Chauncey Ave, Etobicoke, ON M8Z 2Z2

    – E-mail:

    – link to contact form:

    How is basement waterproofing done on the outside?

    At Tornado Plumbing & Drains, external excavation and waterproofing is executed in 7 steps as follows:

    1. Foundation wall deep excavating to the footing.
    2. Removing the weeping tile out of the area of excavation.
    3. The foundation wall cleaning for better adhesion of the future coating.
    4. Applying the foundation coating onto the exposed wall for successful waterproofing of the basement (remember that an elastomeric rubber coating is the best option, though not all the contractors use it).
    5. Installing of the foundation wrap or air-gap/dimpled sheet membrane on the foundation wall for better damp-proofing.
    6. Installing of the new drain/weeping tile covered with gravel.
    7. Checking and confirming that the new drainage system works properly.

    Guarantees and warranties you can count on

    FAQ: Exterior basement waterproofing outside

    Why Should I Waterproof Basement Outside

    Exterior basement waterproofing is the best way for preventing water in your home.

    Do not get confused about the complexity and heavy costs of basement waterproofing. Remember that leaky walls of your foundation or water that wells up from the basement floor can cause so much damage that it will be much costlier for you to repair it. If you manage basement waterproofing once, you will spare yourself of more severe problems in the long run.

    How much does it cost?

    The average cost to waterproof a basement is $0,000 to $0,000, or between $0 and $0 per square foot for materials and labor.

    How to choose contractors?

    • Find contractors on google or dig into internet directories
    • Check their portfolio
    • Proof of a valid license
    • Check reviews
    • Get free quotes
    • Get an extensive warranty

    Is interior or outdoor waterproofing better?

    The drain tiles will carry water away from the foundation before it has a chance to enter the basement. … Exterior waterproofing is also more expensive than interior waterproofing, because it requires more work and more material, but it efficiently stops water from getting close to the foundation of your home.

    What Are the Benefits of Exterior Basement Waterproofing?

    It prevents water from entering your basement rather than managing water that has already gotten in. It directs water to the exterior drainage system, away from your foundation. The gravel relieves the hydrostatic pressure that can otherwise build up. Most importantly, it gives you a truly dry, pleasant basement. Having an exterior basement waterproofing system means the elimination not only of seepage or wet spots, but of nasty musty odors as well, so your basement becomes usable living space. 

    When the leak happens at the point of joining between the wall and the floor, it is called  a cove joint leak. Why does this occur so often?

    When the construction process of the house starts, workers dig the big hole in the ground first. They pour the concrete into it up to the surface. Such a footing can reliably support the wall of the foundation making up the basement of the building. The platform that is created prevents possible settling processes or rising of the house at one end of it.

    To pour the concrete mixed with water, they make a wooden frame first. Before the cement dries out, a special board of a conical shape is placed in its center from one edge of the frame to the other. It helps create a channel that is called a keyway. This is a sort of a path going across the whole footing.

    When the cement dries, one more frame is located on it. It is meant for building the foundation walls. They also fill it with concrete and let it dry. The lower part of this frame fits perfectly into the keyway of the bottom layer. After drying out, the wall is fastened in the keyway like the pieces of the puzzle that fit into each other.

    This is the very point where the wall is joined with the footing. That is what we call the cove joint. In this way, any side movement or shifting of the wall is prevented. However, the foundation wall and footing do not merge into one piece. They are separate pieces of the construction that are joined together. They fit into one another tightly like the socket and the plug. Though they are still different pieces and there is always some little space for the water from the ground to enter and stay there.

    The water that has entered into this gap between the keyway of the footing and the wall, starts seeping into the home and becomes a cause of the leak. Such a leak is considered a cove joint one.

    Let us consider the three common reasons why water is leaking into basement after heavy rain:

    1. The Issue with the Drainage System. If the drain pipes are blocked by some obstacle or damaged, they need much attention. You should think about clearing out, repairing, or replacing them. There are also issues connected with the flooring condition. If the floor is laid immediately on the drains and, moreover, it has a carpet, hardwood, or laminate covering, you can sometimes see that something is wrong with it. The cause may be in the blocked drains because of the lack of spare space between the covering and the pipe, so the excess water starts seeping from beneath the flooring causing its damage and other unpleasant issues.
    2. The Pipes That Leak. The water supply pipes are usually hidden in the walls. They can make a big problem when one of them starts leaking. The water that seeps from the leak runs down the wall onto the floor of the basement and pools there. Then, you can observe it seeping from the floor and it is a very unpleasant issue because the walls and the floor in your home are, as a rule, finished, so you need to spend much effort on repairing and restoring them.
    3. The Water Seeping from the Ground. The heavy rains that occur in your place or speedy melting of the snow in spring produce much water. It is absorbed by the ground but if the soil is saturated, the pressure becomes very heavy, and the excess water penetrates your home’s foundation and seeps into the basement via the floor or walls.


    When you encounter some basement floor wet spots, it is a sign that water has started seeping into the basement through a crack.

    The concrete that is used for making the footing is mostly porous. If it is sealed badly or not sealed at all, the capillary action comes to being and the footing starts absorbing the groundwater. The groundwater produces the hydrostatic pressure. If it is too much, it influences the sole construction of the basement wall.


    Different types of masonry may accumulate a white deposit on their surface which is called efflorescence. Most often, it appears on concrete, tiles, and brick. When you see this powdery layer on the foundation walls of your house, this is a sign that water seeps somewhere into it. The mechanism of this phenomenon is very simple. Such minerals as salt are carried by water and stay within the material when this water seeps through them. Then, it evaporates leaving the white mineral traces on the surface.

    Windows That Leak

    The windows that were not puttied and sealed properly can have leaks. It is especially a characteristic of the basement windows. When it is rainy, the water is leaking into the window gaps. So, look attentively whether you have any puddles or pools around the window after rain. Maybe you will need to seal the window frames again or even apply the caulk anew.

    Mortar Joints

    Mortar is usually used to fill the gaps between the bricks or blocks of concrete. This area is called a mortar joint. Since mortar is a highly porous substance, it forms cracks easily. These cracks make up a great way for the excess water to seep into your basement.


    The plumbing system when it is not in a good working order is always the main source of leakage. When the pipes are frozen and burst, the leaks appear immediately so be very careful and always look at the joints to identify the problem. If your toilet is running very often, the leaks may occur too.

    Groundwater Around Foundation

    The porous concrete your basement is made of  can allow for water seeping in any place of the foundation. It is not necessarily the rain or flood water that seeps into your house. Groundwater is often the cause of seeping as well. It is especially expectable when the ground around the foundation is dipped and some shallow moats are formed by it. The water from the ground is collected in this moat  and leaks into the basement. That is why experts recommend sloping as the most effective way to protect your house against the groundwater.


    If you obviously detect leaking but cannot identify the exact cause of it, you need to refer your issue to an expert. Some day, the problem will get even worse if left unattended, and you will have to pay much more for the extensive repairs.

    The Main Causes of Water Seeping Up from the Ground

    1) water pipes that are damaged or broken;

    2) spring snow melting that may cause a breakthrough;

    3) the septic system that is overfilled and not maintained for a long time;

    4) the French drain or drain pipes that are broken;

    5) the leach field of the septic system that is failing;

    6) the damaged sewer pipes;

    7) the overflowing of the natural (artesian) well;

    8) the neighbors changed the direction of their drainage system, installed new gutters or downspouts, or set the drainage control appliance so the water collects now in the lowest spot of your backyard.