basement waterproofing

Foundation problems are pretty common in Toronto, especially in older homes closer to Lake Ontario.  Toronto is a city with a high water level table, meaning many areas experience chronic problems in their basements due to ground water swelling up underneath the foundation.

The earth’s not static beneath your home’s foundations. In fact, it’s a dynamic living thing that reacts to moisture welling up, or coming down as rain. As it absorbs water, it expands, and as it dries out again, it contracts. This translates to your foundation moving up and down during the change of seasons.

While concrete foundations are reinforced and seldom fracture, the brick, mortar and concrete structures standing on them are only hardened to the extent the builders considered necessary.  Fortunately, they give off early warning signals like cracking and splitting when underlying problems start to develop. Depending on the severity of the cause, you could try to fix it yourself, or ignore it at your peril.

Warning Signs

a stairstep crack in a cinderblock basement wall

Where there’s sudden, catastrophic erosion after a severe flood, the problem may display as a seriously tilting house that could finally collapse. Where the problem is chronic due to fundamental soil conditions, the indications are likely to be more subtle and could include the following:

  • Step-cracks in brick walls that spread out from structurally weak points like openings and corners. These typically open wide in drought, and close again when the earth below is moist and expands. The power of heaving soil is mighty and it’s pointless trying to patch them. You have to tackle the foundation problem that’s causing them first.


  • Movement in the walls may also display as sticking doors and windows during rainy periods, and correspondingly loose ones when it’s dry. Here, it’s often possible to apply a flexible seal to keep out the draught. Once again, this is just a temporary solution.


  • A more serious problem is indicated when a concrete floor starts to crack, either on ground level or down in the basement. If moisture starts finding its way through then a crack is likely caused by a ground-water problem. If not, there’s a likelihood of poorly-compacted earth beneath.

Tackle the Problem

Subsiding foundations and cracking walls are not a job the average homeowner should tackle themselves. The work is highly technical, especially because it’s seldom possible to inspect the root cause of the problem without an experienced foundation contractor employing special detention tools. Moreover, exposing foundations is hard work that requires specialized equipment.

Seek Independent Advice First

Arrange to have your home inspected by a registered, competent structural foundation contractor. Get a few opinions to be sure you’re going with the right solution as it foundation repairs are usually a fairly big job. Sometimes, your problem turns out minor and you can just learn to live with it. At other times, a trained expert can provide a detailed specification of what needs to be done (and inspect the job as it goes along too).

Appoint a Foundation Repair Specialist

Again, remedial foundation work is hardly the job for the average contractor (or worse still the local handyman). You need to find someone who can repair the underlying problems, fix the consequences like cracked walls, get rid of damp problems and ensuing mold, and finally, provide an effective guarantee against a return of the problem.  If you’re in Toronto, you’ve probably seen stories like this one where inexperienced and low priced contractors were hired to do a complex job, resulting in dangerous and expensive results.

If you have questions about your foundation and would like an expert, no obligation opinion, contact us here.




Over the past 30 years, Nusite Group Contractors has performed several hundred interior and exterior basement waterproofing jobs all over Toronto and the surrounding GTA.  Homeowners that have wet or leaky basements are often confused as to how the waterproofing process works.  While in some cases, an interior waterproofing job is sufficient, often times it will not mask the underlying water problems surrounding your foundation.  In this case, exterior waterproofing is your best bet for doing the job once and for all.

When a basement foundation needs to be waterproofed, a series of steps must be followed sequentially to do it correctly. All repairs and prep work has to be completed before the membrane is applied. The membrane must be made from a quality material. In our case, we use Bakor Waterproofing, which is a superior product and provides excellent and long lasting protection for the basement exterior foundation to prevent further leaks or seepage.

Here are the steps which we take to waterproof a basement foundation.

 #1 Excavate the Basement Foundation

Basement waterproofing membrane being applied to Toronto home

Normally, we excavate the area around the home by hand. We do this because mainly to minimize any potential damage which machinery might cause. However, if it is possible to use machinery to complete the excavation faster, we will do so.

The basement foundation will be excavated down to the footing so the basement walls are completely exposed. We will excavate down to the level of the weeping tiles, or the lowest point of the footings to ensure the footings are at the correct depth. Shoring will be used in some situations to prevent the possibility of a cave-in.

Then, we will use a combination of wire brushing and power washing (only if the wall is a concrete foundation) to clean off the dirt so we can properly evaluate any existing damage to the foundation walls. Once the state and condition of the footings and the foundation of walls has been evaluated, we will begin our repair.


#2 Basement Foundation Repairs

Exterior crack being filled on Toronto basement

First, we manually chisel out any visible cracks or gaps in the foundation wall. These gaps and cracks are then filled with a hydraulic concrete to fill all the voids.

Some basement walls may still be rough and uneven. To properly and effectively apply the sealant membrane, we may have to apply a parging coat to properly smooth the walls which may require up to 2 coats. The parging acts as a means to damp proof the foundation walls along with providing a more consistent medium to apply the waterproofing membrane.


#3 Apply the Waterproofing Membrane

A waterproofing membrane that has been applied to a Toronto basement foundation

The next step is to apply one of two types of membrane sealants which will be either Aquabloc 720-38 or CM-100 series liquid membrane. Different types of membrane material are required for different types of foundation walls. The important thing to remember is that a waterproofing membrane is the only cost effective and most efficient way to waterproof the exterior basement foundation walls, as some competitors will employ cheaper methods which in fact only damp proof the wall. This approach is far less effective than the waterproofing materials that we use.

The waterproofing material is applied to every square inch of the foundation walls. This membrane is the primary material which waterproofs the foundation walls and prevents water from entering.

The membrane then requires a mesh to hold the material and keep and cracks or gaps effectively sealed. The mesh we use to use reinforce the waterproofing membrane is Yellow Jacket mesh which adheres to the membrane.


#4 Apply a Drainage Board Membrane

The next step is to apply a drainage board membrane to the exterior of the waterproofing membrane. This secondary membrane acts as your first defense against water and frost and also protects the waterproofing membrane when the excavated foundation is filled back in.

The drainage board membrane is a dimple board membrane. The dimpling effect provides a space between the waterproofed walls so the dimple membrane has an air space which allows any water that enters the air space to drain effectively to the weeping tile.

After the dimple membrane is applied, it is then sully sealed along the seams. The dimple membrane is then finished with a termination strip at the top of the membrane to tightly seal the membrane and affix it to the wall. We then apply concrete anchors to effectively secure the dimple membrane along the termination strips.


#5 Weeping Tile Steps

weeping tiles installed on exterior foundation in Toronto home

Effective drainage is very important to keeping a basement waterproofed, so addressing the weeping tile is the next step which is equally vital to the process because water needs a place to go. There are many different types and sizes of material used for weeping tile.

Regardless of the weeping tile you currently have, it should be replaced with the best possible material. New technology now exists for a more durable and more efficient weeping tile. The weeping tile we usually use is a new form of perforated plastic tile that is covered with a sock. The purpose of the sock is to prevent sand from entering and clogging the tile which make drianage ineffective.

Once the weeping tile is replaced, we then cover it with a landscape fabric and then a clear layer of 6 – 12 inch stones. One thing to keep in mind is that if you also have a window that is within 6 inches of the top of the level grade (meaning after the excavated hole is back-filled), you will also require the installation of a vertical drain which is attached to the weeping tile to ensure effective drainage of any water which might seep in around the window.


#6 Backfilling the Excavated Basement Hole

Backfilled foundation on Toronto home

This is the final step to the process and should also be done correctly as it is simply not enough to push the excavated material back into the hole. A compactor must be used to properly tamp down the earth and done in such a manner to avoid any possible damage to gas lines or other underground utility connections. Proper backfilling also allows for proper grading which must be sloped away from the house. It also ensures there are no larger piles of dirt that needs to be settled.

The landscaping can also be repaired by us afterwards, but you should be aware that it can take up to 3 months before the dirt fully settles.


So these are the steps taken when performing an exterior basement waterproofing project.  It may seem like alot of work, and it is, but many times it’s the only way to ensure you can enjoy a healthy and dry basement.  To have such a big project performed successfully, make sure the contractor you use is fully qualified and licensed and is using the highest quality materials for the job.  As you can see from these steps, it’s not something you’d want to have to do again.  Have questions about basement waterproofing?  Contact us here, we’re happy to help!

If you think your basement is perfectly waterproofed forever, then think again. If you’re home is in a location with a high water table, like here in Toronto, leaky basements can be a chronic problem….especially for older homes.Take a look at the illustration below. While everything may have been perfect the day the builder handed over the keys, foundations do settle, and joints can wear out. Let’s work through the picture point by point, starting from the top to see where water can potentially enter your basement.

sources of basement leaks in home

  • Window Wells – Your waterproofing’s only as good as the quality of your window well. There’s absolutely no point in trying to waterproof it from the inside. You must ensure that the surround is high enough to keep the ground water out, that the drain is kept clear, and that the window itself is well caulked and jointed.


  • Tops of Walls – It’s not uncommon to find water entering at the top of the basement wall where the main building rests. This is usually because rainwater is finding its way in. Assuming this is something that’s developed recently it’s likely that the earth is piled higher than it should, or that a recent alteration has caused the problem. Fix the problem where it starts.



  • Pipes – Pretty much the same goes for holes made through walls where supply pipes and drains penetrate. The water that’s still inside the wall when you seal it will eventually break down the water-soluble ingredients of the material. The only counter for this is regular inspection and joint replacement.


  • A Weak Concrete Mix may result in water finding its way through a porous section. If this is only a small area there’s a possibility of chopping out and replacing. If not, then the only option is to work within the situation, by leading the water to a sump pump from where you can pump it away.


  • Coves – These are the joints where the walls rest on the floor. Unfortunately the systems builders install in an attempt to avoid problems become blocked by debris over time. The answer is to either unblock them, or to install new french drains and a sump pump.


  • By far the toughest nuts to crack are fractured concrete floors, or water welling up though them. This is because there is seldom any chance at all of reaching the source of the problem. In this case, you really do need to call in a basement waterproofing specialist. You’ll likely have to evacuate the area if it’s used as living space, as it will remain uninhabitable until a proper waterproofing solution is implemented.

Severe basement leaks are hardly jobs for amateurs. Unhealthy damp can cause respiratory problems and result in permanent mold. Underground damp’s not going to go away. In fact it’s only going to get worse. Call in a basement waterproofing specialist, before there’s permanent damage done.

French Drains in Your Home

French Drains have nothing at all to do with France. Their name comes from Henry Flagg French from Concord, Massachusetts, who invented them in 1859. In simplest terms, they are trenches filled with gravel that act as conduits for water runoff. They remain popular ways to remove unwanted water from our basements, as Mr. French originally intended.

anatomy of a french drain system

What’s in a Name?

French drains used to have other names like weeping tile drains, soakaways, rock drains, rubble drains, perimeter drains and even French ditches. These terms originally described the different methods of constructing them. These days, the term “French Drain” applies almost universally, although not all French Drains follow the same design. They all do exactly the same thing though, and that’s to lead water away when it’s not wanted.

Methods of Construction

Before the advent of Henry Flagg French, people dug ditches to take water where they wanted it. These ditches had two disadvantages. They became blocked. Moreover, livestock and people fell into them (and sometimes even drowned). Boarding them over changed nothing except that it became more difficult to clear the stoppages.

Mr. French stumbled over the idea of filling drainage trenches with medium-sized stones. This solved both ditch problems simultaneously because:

  •   Blockages occurred at the entry point and were cleared easily
  •   There was no longer a hole to fall into

The final stage was to fill in over the stones with compacted earth (or even concrete). After that, people seldom even knew the French Drains were there.

drawing of how a french drain system works

Getting the Water into the Drain

This is not as daft as it sounds. When you allow the surface water to enter the drain naturally from the top using gravity feed, there’s a good chance of it backing up in unusually wet conditions and blocking easily. Engineers solved this problem by introducing perforated pipes inserted into the stone fill. That way, if the water started backing up it simply moved back up the tube.

French Drains also drain soggy ground like bogs and marshland. In this case, the builders apply permeable membranes along the length before they add the stones. Water can then enter the trench at any point along the length, greatly increasing the efficiency of absorption while reducing the possibility of blockages from the sides.

What to Fill French Drains With

You can fill a French Drain with almost anything provided it doesn’t rot, holds back a potential blockage and allows the water to filter through. Material can be anything from gravel through broken bricks and tiles to natural stones. It’s customary to use larger pieces in the center, because this speeds up the flow of water.

French Drains in Our Homes

French Drains are present in many Canadian homes, although their owners may be unaware of them. Common applications include:

  •  Placing them just outside external walls to prevent water ingress
  •  Positioning them under floors to prevent water upwelling
  •  Installing them inside basements, in which case the water flows to a sump pump

Despite the best intentions in the world, nothing lasts forever. Older French Drains do clog up eventually especially where permeable membranes are absent. The symptom of this happening is the gradually appearance of groundwater. The solution is to call in an expert to open them up, clean them out, and then reinstate them professionally.

Do you live in Toronto or the surrounding GTA?  Contact us today for a free on-site inspection and estimate.



wet basements Richmond Hill-TorontoDoes your Toronto home have a wet basement?

A chronic wet basement is a sign that you have a serious problem that needs to be addressed as soon as possible. A basement that is chronically wet can mean you have potential foundation problems. Damp or wet basements can lead to structural issues, water damage, and potential health problems such as mould and mildew growth.

There are many reasons why people use their basements. Some of the reasons you use your basement could include using the basements for additional living space, recreational, a home office, or just simply as storage space. Regardless of the reason, if you have a moisture problem, leakage or some degree of flooding, you need to address the problem because it will not go away on its own.

The only solution to correct your basement’s water issues is to determine the source of the moisture. Most commonly wet and leaking basement problems are remedied through waterproofing your Toronto basement.

However, you need to be aware that not all basements are the same. There are many reasons and causes why your basement leaks or is wet, so there are a variety of waterproofing solutions that can be used to fix your particular problem.

Also, not all basements are constructed the same as foundations for homes can be different, especially in older homes. Building codes and materials used in the construction of basement foundations have evolved over time.

Also, everything changes from the effects of wear and tear, and is subject to movement, erosion, and temperature extremes, just to name a few. Even newer homes can have leakage or seepage problems from different causes.

Reasons for your wet and damp basement problems

Let’s look at some of the causes in more detail for a leaking or wet basement. It can range from hydrostatic (fluid) pressure, deterioration of the foundation from water or frost, shifting and movement of the soil, and a host of other reasons. Each cause needs to be determined and corrected properly or the problem will likely recur again.

Some of the reasons for your wet basement can include one or several of the causes;

Cracked Foundation Walls

Leaks can occur from cracks in the foundation walls or floors of your basement. They allow moisture and even critical leaks of water to occur. These cracks may appear small on the inside of the basement, but even small hairline cracks will leak over time. You might think a simple patch job will fix the problem, but it will do so only temporarily. The problem has to be fixed from the outside through excavation and a full repair. We may employ an interior solution but only if the problem cannot be repaired from the exterior.

cracked foundation wall in toronto basement


Many people experience flooding in their homes because of a heavy snowfall followed by a sudden warm spell which the clogged and ice covered municipal drain systems can’t handle. Even more problematic are the sudden and heavy rainfalls which also overload the system. Sometimes this is confused with a significant problem, or that waterproofing someone previously completed is not functional. However, it is best to let a professional assess the source of the flood and advise accordingly.

Water Table

The water table varies throughout the city of Toronto, and also varies according to amount of rain. You may not have experienced any problems for years. All of a sudden you have leakage, seepage or flooding problems that appear inexplicable. This problem will flood the subfloor of the basement, and does not allow the weeping tile to “weep” water down underneath the finished space of the home.

toronto has a high water table

Drainage Problems

Poor drainage is another major cause of wet basements. Water can suddenly start to appear as if it’s leaking up through the floor. It may appear where the walls and floor meet or come through cracks in the wall. There are different types of drainage systems used which range from French drains to crushed stones. For one reason or another, there may be damage or the system becomes plugged which causes the water to back-up.

Eaves trough Problems

An eaves trough system is used to prevent rain water and melting snow from overloading the drainage system and direct it away from the house. Unfortunately, many people neglect to keep the eaves trough in good repair, and let it to become clogged, or fail to ensure the water is being drained away from the home.

cracks in troughs can lead to basement leaks

Window Wells

Poorly constructed or badly maintained window wells can also cause your basement to experience leakage or moisture problems. Most often these wells require a little maintenance which can help stop leaks seeping through below grade windows! Any window within six inches of the ground requires a well with a drain to the footing!

window wells are a source of basement water leaks

Waterproofing Solutions

Depending on the cause of your wet basement problems, you will need the right solution to permanently fix the problem. The proper waterproofing solution will save you aggravation, prevent health and humidity problems. Additionally, proper waterproofing will give added value to your Toronto home.

There are 2 approaches that can be taken when to waterproofing your basement. They are interior repairs and exterior repairs. Truthfully though, the interior repair is not a real waterproofing solution, and is used for areas when the exterior of the foundation cannot be accessed.

Interior repairs are also used when lowering a basement. This process means that the floor and utilities are lowered, so the weeping tile and drainage board must also be lowered to account for the new depths.

Real waterproofing occurs from the exterior repair of the basement where we employ various layers of membranes to ensure no water can penetrate the worked on area.

Let’s examine both solutions in more detail so you will properly understand the differences.

Drawbacks of Interior Basement Waterproofing

Interior basement waterproofing does not employ the use of a sealant. True interior waterproofing allows a membrane to be installed into the interior of the home where we divert water underneath the basement floor to a drainage system (interior weeping tile).

Applying an over the counter sealant on the interior of a basement wall or floor, will likely result in causing the moisture to be trapped in the cracks, and cause further eroding of the foundation. The foundation problems will worsen over time. If the problem is caused by problems in the exterior drainage system or cracks, the interior is a more temporary solution as water still enters but is diverted.

Another drawback of this solution is that if repairs are performed incorrectly you are likely going to be creating standing water. This will perpetuate problems of high humidity, and can develop health hazards from mould infestation which can spread throughout the house.

Interior repairs are only to be performed after evaluating the state of the basement foundation and the severity of the problem. Usually the interior repair is done only until you can fix any existing or apparent problems on the exterior of the basement foundation.

Benefits of Exterior Basement Waterproofing

The best approach to have your Toronto home waterproofed, and to do so correctly, is to perform an exterior repair. This is the only way you can solve drainage issues and to properly correct any problems with the foundation of your home and prevent further structural damage.

exterior waterproofing on Toronto home

How Exterior Basement Waterproofing Works

The first approach would be to correct any problems with the drainage system such as the weeping tiles, and fix any existing foundation problems in the footing or walls of the basement.

After correcting any existing problems which may make excavation unsafe, the exterior of the basement foundation walls and footings are fully excavated. When exposed, the walls are then covered with a special hydraulic concrete and liquid tar like membrane.

This process prevents the advent of moisture and acts as a permanent barrier. The exterior is then re-enforced with a mesh, and the tar is re-applied. A drainage board is installed along with new weeping tile, landscape fabric, clear stone and finish strips.

How long do these liquid membranes last? These membranes have a shelf life prescribed by the manufacturer, but most carry a functional life span of ten years. They are designed to stay elastomeric (never cures hard).

Regardless of what caused the leakage or seepage into your basement, selecting the best waterproofing membranes is always the correct way to repair a wall. The only way to fix failed tar is to dig it back up, so it must be done correctly the first time.

Waterproofing Versus Damp Proofing

When your home is constructed new, it is initially damp proofed to allow the concrete or foundation block to dry. This means that only 99% of the water is deterred from the wall allowing some escape of moisture so the wall can dry. Conversely, this means over time that water can and will enter the wall.

You must understand that damp proofing is part of the building code in Ontario, and lasts an indefinite amount of time. When we employ waterproofing membranes, 100% of the water is kept out of the wall to avoid frost issues, prevents water penetration through absorption, or covers any gaps, cracks, and holes that may leak. This only can be done with exterior repairs!


Some contractors might promote the notion of a ‘quick fix’ by suggesting that you strictly use a sealant as a cheaper alternative to fixing your leaky basement, but the money you save now will most likely end up costing you a lot more down the road.

Your best bet is contact a qualified and licensed waterproofing contractor and to have your basement properly inspected with moisture tools and repaired by a reputable waterproofing contractor.