basement waterproofing

What Is a False Water Table?

False water table in Toronto basementFalse water tables can spell trouble for your basement or crawl space, even when these areas are waterproofed. As a homeowner, it can be frustrating when water keeps seeping into these areas when you thought you were protected.  Here in Toronto, almost all homes have basements and with the weather conditions and underground waterways running through Toronto, water seeping into the basement is a constant issue for Toronto homeowners.

Sometimes homeowners think their home is sitting on a high water table, when in fact their house sits over a false water table created by loose back fill.

How False Water Tables Form

A false water table forms because of the process used to excavate for your home. A hole is dug in hard-packed soil for the foundation. After the foundation is built, soil is “back filled” around the perimeter. This fill is not as compacted as the undisturbed soil beyond the foundation area. As a result, water penetrates where it can enter easily; around your home. When it rains, or when snow melts, the water follows the path of least resistance and flows away from the hard-packed, undisturbed soil towards the looser, more porous back fill.

Diagram image of a false water table in Toronto basement

Water that has accumulated will continue to rise if water is coming in too quickly, or the real water table is full and cannot handle any more water. As water always seeks to level itself out, it presses into all the voids in the soil, under the foundation and in the foundation walls. The water will continue to climb as long as there is more water pouring in and this creates what is known as a false water table. This can happen even if your home is built on high ground as the soil around the foundation collects moisture before it has a chance to run off. In the meantime all this water exerts an incredible pressure on your foundation.

Hydrostatic Pressure

Once the false water table fills up and becomes higher than the floor, your trouble really starts. Hydrostatic pressure is 63.4 pounds per cubic foot and the water presses in all directions to find its own level. Most homeowners are not even aware this is happening until there is a heavy rainfall or large amounts of snow are melting. The area under the foundation may store up to 2500 gallons of water, but when this fills the water has to find a place to go. If your foundation has any cracks or weak areas, the water will find it and enter the lower level of your home.

Basement waterproofing in Toronto diagram of basement leaks

Clearly, leaks caused by a false water table cannot be solved with a commercial patch kit. The force is too strong. Excavation alone will not solve the problem either. You will need a system designed specifically for a false water table. This involves both water control and a method of relieving the enormous pressure that builds up against the foundation. This is definitely one problem that you will want expert help with. Failure to attend to a false water table may result in the erosion of your house’s foundation, leading to additional cracks, more damage and additional costs.

Toronto Waterproofing Experts

Contact the experts at Nusite Group for a free inspection and estimate. We use cutting edge technology to find the true source of the basement water leak, which could save you both time and money. We are industry waterproofing experts and service the entire Greater Toronto Area.

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How Much Does It Cost to Waterproof My Basement?

How much does it cost to waterproof my basement?  This is a very popular question and a legitimate one as the costs of waterproofing your basement in Toronto can vary widely depending on the type of waterproofing job involved as well as the size and type of foundation of your home.

Here in Toronto, most homes will have water problems with their foundation at one time or another due to the age of the homes in Toronto as well as the sometimes extreme weather.  Toronto also sits on top of hundreds of underground waterways which does not help.  Many times the homeowner calls in a professional waterproofing company after they have tried to remedy the situation themselves to no avail.

I’m going to assume that you’ve already tried diverting rainwater from your garden, checked your downspouts, adjusted the gradient away from your foundation and identified that your damp problem is not the result of interior humidity. This leaves three options open:

  • Do nothing (unlikely because you’re looking for solutions). This option is also going to become very costly in the long term.
  • Waterproof your home’s foundation from the inside by either fixing the foundation cracks and sealing it or installing an interior weeping tile system to divert water away from your basement. Fixing cracks and using waterproofing paint or sealant is usually a temporary fix as hydrostatic pressure from the exterior will eventually push its way back into the foundation.  Interior waterproofing is not actually waterproofing, it’s water management as you are not stopping the actual water leak source, just diverting the water from your basement.
  • Do it properly by appointing professionals to waterproof the outside of the foundation wall with exterior waterproofing. This is actual waterproofing as you are sealing the basement from the outside, creating an impenetrable water barrier around your foundation. This is the most expensive but most permanent solution.  Pay for quality. Fix the problem.

To help you reach the right decision, here are the average material costs of several common interior waterproofing options you may be able to apply yourself. You’ll need to factor in the cost of labour, and check how to prepare the walls first.  These are very rough estimates and every job can have unforeseen challenges that add to the overall cost.

Before You Start

Water is a persistent thing and finds its way past most things. The Grand Canyon, Ayers Rock, the White Cliffs of Dover and the Rocky Mountains are proof of this. To succeed, you must first fix all the obvious trouble spots first. Use polyurethane caulk @$5.00 / 10oz tube for cracks / gaps under 1/8” wide, and epoxy filler @ $35 / 9oz tube for the rest.

Silicon Concrete Sealer

This penetrating product soaks through the exterior of concrete and brick to create a waterproof surface. You can’t put it over paint because it won’t soak in. Use a sprayer, brush or roller. You can usually paint over it afterwards (check the label) because there’s little risk of cracking and peeling.

Average Cost: 1 gallon costs $45 and covers 200 square feet. You’ll need 2 coats.

Concrete Waterproofing Coat

This is a cement based product with special additives that sticks permanently to raw brick and concrete when fully dry. It stands to reason it won’t dry on wet surfaces without degrading, and it is unsuitable for previously painted surfaces. Apply it with a tampico brush. If you’re an artist, swirl it around to create patterns.

Average Cost: 5 gallons of dry powder will cost $45 and cover 100 square feet.

Waterproof Paint

This is not the most robust option but the simplest for the average homeowner. It’s basically acrylic wall paint except a whole lot thicker. Being paint it sticks to paint and takes over-painting too. Apply it with brush, roller and sprayer just like any other paint.

Average Cost: $35 per gallon which covers only 75 square feet (because it’s thick).

Plastic Sheets / Panels

The sheets and panels cover the walls, and channel the moisture into internal drains from where an electric pump disposes of it. This won’t stop the water from imperceptively degrading the building, but it will conceal the obvious and protect basement contents.

Average Cost: $4,000 for a 400 square foot room of average height.

Exterior Waterproofing – The Sure Fire Solution

None of the above will permanently solve damp basement problems, although silicone and concrete waterproofing may for some time if the crack/leak is very minor. There is only one solution that I’ll put my name to, and that’s an exterior waterproofing solution by excavating around the basement, membraning the walls, and installing outside soak-aways to lead the water away to pumps if necessary.

Average Cost: $15,000 to $30,000 depending on size and complexity.

This is expensive but then quality does come with a price tag. The tragedy is that it shouldn’t be necessary if the builder got it right first time. Don’t make a second mistake by throwing good money after bad. Find somebody with experience to get your basement waterproofing right.

 

About Nusite Waterproofing

Nusite waterproofing is a basement waterproofing company in Toronto.  We are a family owned business and have been serving Toronto and the surrounding GTA for over 30 years.  We offer professional work with great customer service.  Contact us today to schedule a free in-home estimate and inspection of your water leak.

 

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How To Waterproof Your Basement Walls

Water leaking into basements is a common problem here in Toronto.  Due to the weather, aging structures and lots of ground water under Toronto, most homes will have water issues at some point in time.  Also, most older homes were never properly waterproofed during the construction process.

If your basement is is constantly wet or damp you may be able to solve the problem by waterproofing your basement walls. One way to tell if the moisture is originating from the outside or inside of the basement is to attach a square-foot piece of aluminum/tin foil to the inside of one of the walls and leave it for 24 hours. If condensation builds on the outside of foil then it means the moisture is being formed on the inside of the basement due to high humidity. The best solution for this is to install a dehumidifier in the room.

However, if there is condensation on the inside section of the foil facing the wall then you may want to consider waterproofing the walls since the moisture is coming from the outside. This could be the result of poor drainage of the soil or damp soil because the water table is high. In some instances you may be able to solve the issue by waterproofing the interior walls but it’s more effective to waterproof the exterior walls although it’s a costlier solution.

Options For Waterproofing Basement Walls

One way to waterproof the walls is to apply a thick concrete coating. This is a hydraulic cement-like coating which can be used on masonry and concrete walls. The coating is made by adding water to a dry mix and is simply applied with a brush. However, it can’t be applied to painted walls.

You can also apply a silicate-based sealant which are often referred to as densifier. These are also used on walls which haven’t previously been sealed or painted. The sealant soaks into the walls and reacts chemically with the brick or concrete, which in turn creates a firm waterproof surface.

Use foil to find source of leak basement toronto

Since these sealants penetrate into the walls they won’t peel or flake off and in most cases you’ll be able to paint over top of them. These silicate-based sealants can be applied relatively easy with a brush, sprayer or roller but it’s recommended to apply a minimum of two coats.

Another option is to apply waterproofing paint. This is made with an acrylic formula and it’s generally thicker than ordinary paint. You can apply it on painted walls and also paint over it when the walls have dried if you like.

Please be aware that you need to seal any gaps and cracks in the basement walls before applying sealants to them. In general, if a crack is 1/8 of an inch wide or smaller you should be able to seal it with polyurethane caulking which is designed for made for masonry. If the cracks are larger than 1/8 of an inch you should seal them with an epoxy filler. These putty-like sealants can be r\pressed in the cracks with your fingers or a putty knife.

The Best Options For Waterproofing Your Basement Walls

If you’re looking for the most effective way of waterproofing your basement the best bet is to seal your basement walls from the exterior with waterproofing membrane along with a perforated drain system, also known as a weeping tile system. This will mean the area around the house will be excavated down to the foundation walls. Waterproofing membrane or coating is then installed along the outside of the walls with drainage panels. These panels will carry the water down to a French drain located at the bottom of the foundation. The water is then removed with a sump pump or by gravity away from the home’s foundation or removed through a storm drain.

An interior weeping tile drainage system or internal perimeter system could be the best solution in some instances as there’s no excavating involved. This consists of installing a drainage channel under the floor on the inside of the basement. This system is somewhat similar to the exterior drainage method except it’s installed on the inside. Once the drain is installed new walls are constructed on the inside of it making the original walls invisible to the eye. When the system has been inserted you’ll have new walls and any water which seeps through the original walls ends up in the drainage channel and can then be removed by a pump.

Waterproof Your Basement Walls Today

Nusite Waterproofing has been providing advanced waterproofing systems in Toronto for over 30 years.  We are a family run business focused on customer service and excellent work.  We serve Toronto the GTA.  Contact us today for a free on-site estimate.

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How Does an Exterior Weeping Tile System Work?

Here in Toronto, installing weeping tile systems on the exterior of the foundation wall is a must if you will be waterproofing the exterior of your home’s foundation.  Toronto is built on top of a large water aquifer, with hundreds of underground waterways.  Many areas of Toronto also have high water table issues, where a good thunderstorm can wreck havoc on a home’s foundation.  An exterior weeping tile system will remove the water buildup on the outside of your foundation and carry it away safely from your home.

When contractors dig out for a basement, they inevitably remove more earth than is strictly necessary. This could be because the soil is unstable, and they do not want it to collapse against a “raw wall”. It’s usually also to make space for a weeping tile system that can help keep the basement dry forever by removing water from outside your foundation wall so it cannot seep into your basement.

An exterior weeping tile system works in similar fashion as an interior weeping tile system, except that water is removed before it has a chance to seep into your foundation walls. Usually, an interior weeping tile is used when, for whatever reason, the exterior of the foundation cannot be dug out and waterproofed properly.

Finished Weeping Tile

Interior Weeping Tile

 

Once the exterior weeping tile system is installed, contractors backfill the space with the soil they dug out previously. Strictly speaking, they should tamp it down as the wall builds up to ground level – and then cover it with a sloping hard-standing to lead the water away from the foundation. Less diligent contractors simply pour in barrow-loads of loose soil at the end of the job, tidy up, request payment and go.  This will inevitably lead to water build up against your foundation, and eventually more water leaking through the foundation.

Installing an exterior weeping tile system is a fairly big job as you will need to dig out the foundation of your home, which is why it is very (and I stress very) important to have the exterior weeping tile system installed properly the first time as the only remedy for an improperly installed exterior weeping tile system is to dig out the foundation again and fix it.

4-weeping-tiles-foundation-300x199 (2)

Exterior Weeping Tile System

Water inevitably finds its way down into the ground to reach the outside of a basement wall, no matter what a homeowner tries to do. If it’s not percolating down through the backfill, then it’s seeping between the strata towards it anyway. When that happens, you have only two defenses:

        1.  A solid, crack-free, fully waterproofed intact                      structure comprising walls, floor and sometimes concrete ceiling.

        2.  A set of weeping tiles installed all around the outside of the foundation, to lead ground water                  away before it causes damage.

 

*Weeping tiles are an essential belt-and-braces feature of any well-designed basement. That’s because earth expands, shifts and contracts, and inevitably challenges the structure’s own defenses.

 

Diagram of How exterior weeping tile system works

Exterior Weeping Tile System Diagram

How Do Weeping Tiles Work?

Don’t be confused by the term “weeping tile”. Weeping tiles are not tiles at all (although they were once perforated pipes made from clay). These days, weeping tiles are made from 4” diameter plastic pipe regularly punched with holes. The idea being that ground water will find its way into them through the holes, and then follow a gentle incline until it discharges naturally (or enters a sump pump for pumping out).

Before the plastic pipes are buried, they are covered with a long open “sock” or overlapping socks made from rot-proof permeable material. This prevents the earth from clogging up the holes, much in the same way as the original weeping tiles may have kept the underground ditches clear.

Weeping tile systems also need to be graded properly so that water in the pipes will make its way towards the final discharge point.

 

Header-Plugged-With-Gravel-Needs-to-be-Replaced 2 (1)Having Weeping Tile Problems?

This is most likely because the long, open socks (or holes in old clay pipes) have become clogged. These days, this can largely be avoided by covering the pipes with fine gravel. Unfortunately, when they do clog there’s little option but to dig them up and lay in new ones. If installed properly, an exterior weeping tile system should work fine for many years.

 

Have questions about installing an exterior weeping tile system or repairs to your existing system?  Nusite Waterproofing has been installing and repairing exterior weeping tile systems in Toronto for over 30 years.  We have an A+ Rating with the BBB and are a top rated waterproofing company in Toronto on Homestars.  We offer free, in-home estimates and inspections and can point out where and how water is entering your basement.

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Why is Water Seeping through My Basement Floor?

 

Do you have water seeping through your basement floor?  Many homes in Toronto do, this is largely due to the age of the homes here as well as the fact many parts of Toronto sit on top of high water tables from the many underground rivers that flow under it.

Basements are an inevitable target for water. That’s because they’re underground, and there’s almost always moisture somewhere nearby waiting to get into your basement through a crack or seam.  If you think of an inground swimming pool, that’s what a basement is, except it’s trying to keep the water out instead of in. While a well-built, properly water-proofed basement could remain dry almost indefinitely, many others fail, because the foundation was not properly waterproofed in the first place or the repair job was more of a bandaid rather than a long-term waterproofing solution.

Water Leaking into Basement Floor

Diagram of water seeping through basement floor

 

Reasons for the Problem

There are several causes for wet basements. These can occur simultaneously. For purposes of simplicity we separate them below.

  • Ground Water – This either filters down from rainwater accumulating above, or through horizontal strata in the ground. If your basement damp problem worsens in rainy months, this could be a likely cause.
  • Backed-Up Sewer Pipes – Many older Canadian homes still have storm water run-offs connected to their sewer lines. If your damp problem traces to an overflowing toilet, then you need to modify your drainage system.
  • Leaking Pipes – Some plumbers have a habit of concealing pipes in walls. All pipes have to pass through walls anyway. If your floor stays damp throughout the dry season, then you should call in a plumber to do some tests.

Your problem will most likely be caused by rain water filtering through the earth surrounding your foundation, and coming up against your basement walls and floor where the hydrostatic pressure may be quite intense. If you believe this is the case, your solution depends on a combination of prevention and cure to stop your basement leaks.  When there is too much pressue trying to get into your basement, simple waterproof paint or sealants tend not to work very well.

Before beginning, first tape a sheet of plastic over your basement floor making sure to seal the edges and any joints. Lift it up two weeks later. If the floor’s still damp the water’s rising through it. If not, the problem could be in your walls and you need to look elsewhere.

Preventing Water From Seeping Into Your Basement

There’s little you can do about groundwater travelling horizontally through the ground. You have to deal with it when it arrives, usually with an interior weeping tile system. However if it’s filtering down from the surface overhead, then that’s a completely different matter. Investigate the following:

  • How effectively is the rainwater discharged from your roof? Is it lead away through channels, or pooling in the vicinity of the basement?  Proper runoff from downspouts can help keep water away from your foundation.
  • Does the ground slope steadily away from your home allowing a gentle yet effective runoff?  Grading the spoil to run away from your foundation will help keep water away form your foundation.
  • Turn off your water supply at the entrance to your property. Does the meter stop when everything’s turned off onside? If not there could be a leak in your supply main that’s filtering underground.

Possibilities

Wait a few weeks after implementing the above solutions, preferably during a dry period to let the ground dry out. If there’s still moisture rising through your basement floor you have two options open to you:

  • Remove the surrounding earth and install a weeping tile system that stops the ground water in its tracks.
  • Install a french drain just inside the basement walls, and pump the water to the outside where it can trickle away harmlessly

Water entering your basement through foundation cracks is hardly a DIY project. The work is onerous, and you need protective gear to avoid infections from mold and water borne illnesses.  Besides, is this really the way you want to spend a month of weekends? If you live in Toronto or the surrounding GTA, Nusite Waterproofing can come to your home and conduct a free in-home inspection of your problem and provide you with a written quote.  We can also go over all available options to fix your basement leaks so you can make an informed decision.  Contact us today to get started.

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