basement waterproofing

As a basement waterproofing company, we often get calls for leaks in the basement during heavy rain fall.  Often times,  cracks and leaks around  a worn and decaying window well is the source for these water problems in the basement..

There are a variety of window well designs available. Some are deep, and closed in on top for safety. Others are shallow and open to the elements. All have the same basic purpose. That’s to admit light through a window in a basement wall.  The well around the window is meant to prevent without water to accumulate or leak past the window pane and down the basement wall.

window well in Toronto basement

Ways to Keep Window Well Water Out

  • Keep Surface Water Away – If water pools around the barrier wall it’s eventually going to find a way through. Make sure the ground slopes away from the well on all three sides, and that there’s no water splashing down directly from the roof. Check the outer side of the wall for any cracks or leaks, and seal suspect joints. If made from brick and mortar, waterproof it from the outside right down to the foundation.


  • Manage the Rain – If your window is entirely below ground level (or just about) then you may like to install a gently sloping roof to keep your basement snug and dry. However the glass will require cleaning regularly and it will no longer be possible to admit fresh air through the window. For that reason, many people prefer to leave their window wells open to the sky. In that case, it’s necessary to install a french drain to lead water that enters the well away.


  • Belts and Braces – As sure as the Good Lord created chickens, every window well has its day when it floods. This is because the roof above might take damage in a storm, or the french drain blocks because it hasn’t been kept clear. In either case, the window well will soon be brimming full of water, and the window becomes your only defense against a flood.

This is why it’s equally important to install a window that’s one hundred per cent waterproof in itself, and to inspect the seals regularly for any wear or damage. Of course, everything will be for naught if someone left the window open before the storm arrived. There’s nothing more capable of ruining your day than a waterfall cascading down into a basement.

creating a decorative garden in window well

The Intelligent Solution

Window wells are an essential feature of any basement – especially if you’re using it as living space – because it admits air and light. If well designed, it also acts as an alternative exit route which some basement might be required by law, depending on your area. By definition it’s also a window opening below the level of the ground. This is a recipe for disaster if the homeowner neglects the window well and lets it fall into decay.

A basement flood is not just another inconvenient insurance claim. There may be no structural damage cover by your insurance company when there’s evidence of neglect. This is definitely not something to attend to on a lazy Sunday afternoon when you finally get round to it.If you’re having some water problems around your window well, or think it might be time to call someone in to take a look at it, give us a call.


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.