basement waterproofing

How to Fix a Humid Basement

Humidity is an expression of the amount of water in the air. Humidity tends to increase during hot summer months, and is can be found indoors in any climate, especially like here on Toronto where we tend to have cold Winters and sometimes Scorching Summers with lots of rain and climate swings in between. We feel uncomfortable when the ambient humidity is high because it reduces the effectiveness of the natural cooling process we call sweating. The higher the ambient humidity level, the happier mould becomes though. And that’s a double-bind that’s best avoided at any time.

Mold in finished basement Toronto

Our basements are mini climatic systems too (although builders set out to ensure they remain as dry as deserts). That’s because the earth we build on is dynamic, and heaves and shifts naturally as its own moisture levels vary. And as it does so, it exerts massive pressure on our basement structures. The almost inescapable result is cracking, followed inevitably by water seepage.

Your Basement – A Lifelong Project

If you have a basement that’s completely watertight, then count yourself among the lucky ones. That’s because, when soil is saturated with rainwater, it’s as good as having a dam outside, thanks to force of hydrostatic pressure. Few cement-based building materials are one hundred per cent waterproof either. True foundation waterproofing uses rubber membranes on the exterior of the home. When you think about it, that’s why we build houses above the ground on foundations, and set roofs on top of them.

Finished basement with musty odour

Your Counter Measures

  1. Detect the Signs – The first thing you need to do is keep your nose tuned in to the slightest distinctive whiff of dampness, humidity or mould downstairs. When you detect something like that, it’s time to conduct a visual examination. That mould or damp spot has to be someplace, and that’s somewhere near the root cause too.

 

  1. Find the Spot – It’s important to remember that damp and humidity vary according to the season, and what’s happening on the far side of the basement. When it’s present on the walls it shows as a blush of water, a trickle or a dribble. On the floor, things are simpler because it forms a puddle somewhere or soaks the flooring above it.

 

  1. Detect the Source – If water’s dripping through the ceiling, it’s likely caused by a leaky pipe upstairs. If it appears on a wall instead, then that wall is either cracked, or the moisture is following a gap caused by an intruding pipe, or during the building process. Water on the floor is either the result of those wall or ceiling leaks, or caused by a more serious problem because you have water welling up from down below.

 

  1. Fix the Problem – While it is possible to seal a tiny crack from inside (although this is never a permanent solution) more serious basement damp problems require professional solutions that involve tackling the problem at its source – and that’s inevitably beyond the walls or below the floor.

We wish we could be more positive about the “instant solutions” offered on the internet and in hardware stores. At best, they conceal the problem while the hidden damage worsens. Using a dehumidifier can reduce the dampness in the basement, but it won’t fix the problem and will leave you with another daily chore of emptying the tank every day.

 

 

Vertical Crack In My Foundation Wall

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Vertical Foundation Wall Cracks

A foundation is the structure on which a home or other building rests. It may be a simple trench filled with concrete on which the brick walls stand. It could also be a concrete-reinforced sheet under the entire building. Where the ground slopes, there may be foundation walls as well, to make up the height difference.

Where a basement is constructed beneath a dwelling, these foundation walls go up to full room height, and receive immense pressure from the weight above them. Unfortunately not all builders make good engineers. If the forces bearing down on foundation walls are incorrectly calculated – or they are inadequately supported by their footings – then the walls will inevitably crack.  Cracks in the foundation can also be a result of shifting of the earth around the foundation, causing enough movement and stress for it to crack.

Toronto home with vertical crack in foundation

Warning Signs

Vertical foundation cracks usually develop during the first few years after construction finishes, as the building settles and the concrete finally cures. They typically start as hairline cracks that progressively open up. A structural engineer is able to measure their movement, and to determine whether the cracks are new developments, or older history.

It is also possible for basement wall cracks to develop when peripheral events affect an existing structure. These could include alterations to the property, blasting in the neighborhood, or even an earth tremor. It’s important to monitor for basement cracking during events like these, so that an insurance or other claim may be lodged before the opportunity expires.

Consequential Problems

Most times a mildly cracked foundation wall is more of an irritation, because it admits moisture and even drops of water through it. Nonetheless, homeowners are strongly advised to consult an a qualified contractor or engineer if in any doubt. The more serious consequence is often a reduction in the value of their home, since buyers often run a mile from the sight of cracks.

“Solutions” That Don’t Always Work

The only sure-fire way to seal a leak is at its source (unless it’s a hairline crack that may be filled with polyurethane). As a professional foundation contractor in Toronto, we get hundreds of calls a year for foundation cracks, including following up on poor attempts to fix them.  The following are examples of botched jobs we often come across:

  • Amateurish attempts like papering over basement wall cracks or filling them with commercial caulking seal. These are inevitably bound to fail as efflorescence builds up behind the sealant causing it to peel away. It’s also almost impossible to obtain a dirt-free, perfectly dry surface with which to bond.

 

  • Commercial filling with hydraulic cement or other rigid substances is also bound to fail, because the structure will still shift with seasons, while the hydrostatic pressure from outside continues unabated. The same applies to epoxy seals to a lesser extent. They may sometimes work for years though – provided they are attached to a perfectly clean dry surface

Flexible, expandable urethane sealants may work where a crack has stabilised. However their elasticity is limited, while cracks can expand by up to 100% quite quickly. For this reason they are not ideal.

The Real Solution

Where vertical foundation wall cracks are serious, or there’s water pouring through them in the rainy season, the only viable solution is to remove the outside soil, to install a french drain or other soak-away system, and to apply a flexible waterproofing sealant or membrane from the outside.

Repairing and/or waterproofing a foundation  can be expensive for the homeowner, it’s also alot of work. If you’re going to do it, be sure it’s being done by a professional that will offer a guarantee on their work and has experience working with foundations.

 

 

Is The Window Well The Cause Of Your Leaky Basement?

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.

 

Steps For Foundation Waterproofing

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!

7 Sources Of A Leaking Basement

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.