Our company provides services in interior and exterior basement waterproofing in Toronto.

Make your basement completely dry and get city rebates for work involved.


Average depth and complexity Exterior Waterproofing costs $115 - $125 per linear foot with excavation, foundation waterproofing and backfill. - see breakdown

Basement Interior Waterproofing in Toronto starts from $80 per linear foot including all materials and labour.

Rock Basements review and Licenses

Benefits of Waterproofing your Basement

Protects Basement

Completely finished basements have so much to loose if water is leaking through foundation wall. On top of eventual waterproofing work you may have to spend money on remodeling of basement after water damage. Rock basements helps to protect already finished basement apartments.

Adds Value for Resale

Toronto housing market is tough and buyers are looking for every small or large detail. having waterproofing done is a confirmation of dry basement that can be used or even rented out. Such a detail increases home value during sale and gives you extra points amongst others.

Enhances Foundation

By redirecting water and applying layers of protective materials we are able to increase the lifespan of foundation walls. Besides eliminating water leaks we tighten walls together and seal cracks that are so dangerous for stability and integrity of house foundation.

Health Benefits

Basement waterproofing in Toronto eliminates all water leaks and decreases humidity. Therefore air in basement becomes better for breathing. Rock basements take care of mold on walls and it should never grow back after waterproofing of foundation is properly done.

Average Costs of
Basement Waterproofing

Type of Work Minimum Cost Maximum Cost

Interior Waterproofing

$80/ln ft
$180/ln ft

Exterior Waterproofing

$105/ln ft
$270/ln ft

Sump Pump Installation


Back Water Valve Installation


French Drain Installation

$140/ln ft
$300/ln ft

Foundation Crack Repair


Two Ways to
Protect Basement

Interior Waterproofing

Exterior Waterproofing


Interior waterproofing is typically thought of as an alternative solution to protect basement from water leaks, when exterior work is not possible or is extremely expensive in given circumstances.

It is a cheaper version to waterproof foundation and can resolve the issue with a minimum of 30 years lifespan.

The way it works is we fix interior cracks of foundation and wrap it with delta membrane to divert any condensate or incoming water towards weeping tile that later disposes it through sump pump system.

Interior waterproofing is a protection rather than prevention method.


The ultimate way to protect basement from water leaks is to do it from exterior. Not only it blocks all the water from outside, but also protects the walls increasing their lifespan.

To avoid demolishing already finished basement we suggest exterior waterproofing of foundation wall.

It is the hardest and more expensive way to waterproof, but the effect is higher than from interior work.

Soil needs to be fully excavated on the exterior of the house to protect concrete or block walls all the way to footings.





As mentioned above, interior waterproofing work on average costs $80 per linear foot. It does vary with circumstances of the project and can be slightly higher or lower.

Factors that affect Interior Waterproofing cost:

  • Size – Larger size projects can be calculated with discount.
  • Demolition – Additional costs for demolishing and disposing.
  • Flood Protection Systems – Sump pump and back water valve.


All projects are different and $120 per linear foot is just an average for Exterior waterproofing work in Toronto.

For the most part cost increases with:

  • Depth of Basement
  • Lack of Access
  • Complicated Soil
  • Sump Pump System


Interior waterproofing works perfectly for unfinished basements. Waterproofing becomes easier to do and no demolition of expensive finishes is required.

The amount of work and timing is shortened for the project. Rock Basements would not have to dig outside and home owners save a lot of money.

Installation of weeping tile inside of the house can be connected to existing sump pump or drainage system.


With exterior waterproofing the house is protected from the outside and has less chance for water to come in.

This technique is superior to anything else builders implement from water leaks and protection of walls under ground.

By stopping water on the outside, we eliminate chance of mold and condensate that can still be harmful to occupier.

Exterior waterproofing is easy and cheap to implement during initial construction or addition of the house.


Unlike exterior work, here we assume that water may have a chance to go through the basement and later interior waterproofing is a way to divert it from finishes towards the weeping tile under slab.

Another problem with interior waterproofing is that we would have to demolish all finishes along perimeter to apply delta membrane and install weeping tile system. 

Lifespan of this type of work is slightly less than exterior protection, and foundation walls crumble with time due to reaction with water that comes down from rain and underground streams.


The cost of exterior waterproofing for the basement seems to be the biggest downside simply because it is more expensive than interior work by thousands.

Excavating outside of the house is not a pleasant scene to have for 1-2 weeks. Although we clean up and try to protect surroundings, landscape may be damaged in process.

Working in Toronto may become a nightmare due to neighbour proximities. Imagine excavating in a tiny walkway between the houses with concrete pathway.

How Waterproofing Works

Protection of basement from water

1. Locate the Problem: Although we recommend entire basement waterproofing, leak has to be found and for extra attention.

2. Expose Foundation/Footing: Digging outside to expose wall or demolishing interior frame with drywall to perform basement waterproofing.

3. Direct Water: Weeping tiles are taking in water that goes down and forward it to drain or sump pump.

4. Protect Walls: Layer of water protective material is applied on wall and delta membrane is attached for extra assurance.

5. Finish: Interior waterproofing is finished with gravel and 4 inch finish concrete, while exterior work is backfilled with tamping soil.

How to Waterproof a Basement?



Our project manager needs to find the exact problem of wet foundation wall before we even propose an estimate with scope of work.

We ensure clients that all stated in agreement work would be done properly and no future leaks are going to occur in same spots.

We always recommend waterproofing entire basement.


Fix Cracks

We imagine your foundation walls are old and have cracks that allow water to go inside after rainfall or underground accumulation.

Large cracks are cleaned from dirt or sand and filled in with specific compound that acts as concrete mixture.

Smaller cracks are enlarged with grinder or concrete saw. Filling process is repeated.


Delta Membrane

Next step is attachment of delta membrane to the wall. It goes from ground level all the way to footing and wraps around weeping tile.

It is additional level of water resistance that redirects it towards weeping tile instead of going into the basement.

Seeing this membrane on basement wall automatically means it is waterproofed.



In Ontario it is illegal to dig or excavate on residential property before ordering and receiving all locates.

It includes gas, bell, hydro, water and all other possible services that are installed underground and can be damaged during excavation.

It may take from few days to two weeks before everything is marked.


Weeping Tile

At the very bottom of foundation wall (next to footing) weeping tile is played to collect all water that comes down the wall.

It is a plastic pipe with holes and wrapped around material to prevent blockage.

Water from around the house and window well goes to weeping tile and diverted to sump pump, which pushes it away from building.



During exterior waterproofing we would have mountains of soil that has to be backfilled into previously made excavations.

By hand or with excavator we put all dirt back and compact it down to make it more stable and prevent it going down later.

Inside waterproofing also requires finishing concrete.



At first we excavate alongside foundation walls where we plan to prevent leak and waterproof basement of the house.

Dirt is piled carefully on plywood or protective material not to damage lawn.

Interior waterproofing is always done by hand, where as outside in some cases we can use mini excavators to dig down.


Blue Skin

Exterior waterproofing always involves blue skin material application on foundation walls to repeal additional water.

It is a rubbery substance that looks like tar. It protects from water and seals additional micro cracks that we cannot see.

Interior waterproofing does not require delta membrane application.


Clean Up

The last thing to do before leaving is the jobsite clean up.

We try to make it pretty after every day of work, but digging dirt around the house is not the cleanest trade.

Our company has the reputation of finishing projects on time and leaving it in cleanest possible condition.

Additional Work We Provide

Ask our project manager for more details

1. Sump pump: Preventative system that collects all from around footings and pushes it in pipe away from house automatically.

2. Back Water Valve: Back up protection that stops city sewers from going towards your basement when overflown.

3. Drains: Rock Basements installs new and substitutes damaged/blocked basement drains for residential and commercial jobs.

4. Water: Need to upgrade main water line from half inch to something bigger? We can do that as well!

5. Window Wells: Our team can install window wells with full excavation and connection of weeper down to footings.

Basement without Waterproofing
6 Common Issues


Without proper waterproofing system, foundation walls are always exposed to soil and exterior water streams.

It makes lifespan much smaller due to chemical reaction and constant worsening of all foundation walls.

Waterproofing can add at least 20-30 years of life to concrete and 15 year to block walls.

It will cost way more to repair these walls later on when they start falling apart.


Very obviously without waterproofing there will be water coming into the basement sooner or later.

It starts as small drops or wet surface after heavy rain, but very soon the problem becomes more than you want to avoid.

As cracks expand, water starts coming in more and more.

It creates other issues and damages to finished basement.


Every time we see water coming inside the basement, there is a chance of mold accumulation.

It grows on cold surface when basement is not protected and properly ventilated.

There are several types of mold and some of them can be dangerous if inhaled.

Molds can grow behind drywall and you wouldn’t even know about potential danger.


When water starts coming into the basement, all sorts of reaction occur with basement installed materials.

Rotten wood, wet drywall and mold on walls comes with very strong smell that irritates ever home owner in Toronto.

The only way to get rid of it is to remove all affected material and waterproof all the walls.

Basements are typically poorly ventilated, therefore smell stays for longer time.


Through condensate or common underground water, foundation walls become moist on the inside with accumulated water drops that run down to the floor.

If basement is not properly waterproofed, water can get inside and react with interior air.

Being underground doesn’t help the situation, because normally basement do not have natural air flow and old ducts are not sufficient enough.

Get waterproofing done and breathe better!


No matter if your basement is finished or not, there will be maintenance needed if foundation walls are not properly waterproofed.

Finished living area needs more maintenance simply because walls and floor will get damaged with water accumulation.

Unfinished basements need touch ups and fixes of actual foundation and casual water mopping.

The sooner it gets done, the more money you can save.

Kate Pona
Waterproofing and sump pump
Read More
I called several companies for estimating fixing basement wall leak and getting rid of moisture. These guys gave me estimate right away during visit and recommended few things. They also helped us get city rebate. Recommend 5+
ALBO Renovations
ALBO Renovations
Underpinning contractors
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We have been working with Rock Basements for several years and contract them for underpinning projects. They do it all, waterproofing, cut outs, walkouts and do it pretty good!
Basement walkout & concrete
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Ivan estimated our walkout from basement with extra concrete work outside faster than everyone. He also helped us with revision of structural detail that saved us some money. Great overall service and finish wrok.
Working together
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Our company interacts with Rock basements on many jobs. We have been doing plumbing after them on many renovation projects and installing drain systems while they excavate basements. Its been easy and pleasant cooperation every time.
Davi C.
Back home addition
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this company did a great job with addition of our house. We hired them to excavate, do footings, foundation walls and concrete floor. This all happened so fast and we just continued from there with framing. Amazing to deal with and very responsive company.
Jenna K.
Basement underpinning
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our home in highpark had very low basement with old foundation walls. Everyone who came to estimate said it was complicated and gave us high price. Rock basements seemed very confident and easy going. It looked like it was a regular project for them and they completed underpinning within 5 weeks.
VeraLinea Design Studio
VeraLinea Design Studio
Basement lowering & additions
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Rock Basements is our go to company when clients ask for referring good rear addition or basement lowering company. We have referred them many times and our clients seem to be extremely satisfied with their work.
Josh L.
Full house waterproofing
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Rock did our home waterproofing with installing sump pump and water valve. Amazing work and i still wonder how they managed to do it only in 4 days.
underpinning with permit
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Everyone told us that getting permits is a nightmare after covid, but rock basements assured us they could do it only within 2 month. We were so surprised! and actual work lasted 6 weeks after permits. if anyone has doubts in them, than sop - they are great
Adam Vik
basement legal unit
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our architect suggested lowering basement by 2.5 feet so we could later apply for basement separate unit. Rock basements did just that within only a month. it was easy to work with and they explained all the details as they were working on footings and walls

When Should You Do
Basement Waterproofing?

Before Interior Renovation

Home owners that are thinking of finishing or completely remodeling their basement should always consider interior or exterior waterproofing.

While walls are exposed it is easier and cheaper to waterproof them from inside. This will give you confidence to finish up basement and convert it into legal apartment.

Waterproofing is a security system of its kind that protects all other finishing materials from being exposed to exterior walls and moisture that may seep through.

Including waterproofing as part of renovation process is not going to break a wallet, but will assure the safety for years.

Known Foundation Leaks

You definitely want to consider waterproofing of foundation walls. Although it may be kind of late and incoming water could have already damaged inside finishes.

The sad part is that most of home owners wait until its too late instead of preventing the problem from even existing.

Protecting basement before damage even occurs or at the construction stage is the cheapest and most proper way, but unfortunately most of the houses in Toronto are old and there was no waterproofing back then.

Contact Rock Basements for free estimate and analysis of leaky foundation wall in your home.

Selling the House

It is not a secret that home buyers are looking to invest their money into safe and protected house.

Who in their right mind wants to live in a house with basement that has leaky foundation walls or potential of mold growth.

Taking core of the basement is a first step to stand out from other properties on the market.

Invest $5000-$15000 into waterproofing basement and have more potential buyer for your property.

Our estimate is free – Contact Rock Basements today!

For Prevention

Don’t wait until water is coming into the basement and prevent it from happening by applying water resistant material on the walls and installing weeping tile to redirect moisture and water.

We understand that home owners don’t want to spend extra money before problem occurs, but in reality it will be way more expensive to waterproof and fix the wall later on.

When house is old it is just a matter of time for water to get in.

Obviously we would not recommend demolishing entire finished basement just to do waterproofing from inside, but outside system would do the trick.

New Build

Although it is completely different process, but waterproofing is an important step when building a new home.

Typically it is done by foundation contractors who pour concrete into forms and later on wrap exterior membrane for protection.

The only problem is some of them are sloppy and use not the greatest materials for waterproofing purposes.

New build waterproofing is cheaper because all walls are already exposed/excavated and we just need to apply blue skin, nail delta membrane to the wall and connect weeping tiles.

The rest can be completed from inside later in the process.

Underpinning and Basement Lowering

Another situation when waterproofing makes complete sense is when lowering the basement.

Once again, the foundation is exposed during the process as waterproofing becomes cheaper and easier to do.

Rock basements (as most of underpinning companies in Toronto) automatically includes waterproofing and sump pump installation into basement lowering estimate.

But it does not work the other way around, and home owners do not consider underpinning simply when foundation wall starts leaking and there is a need to waterproof it.

Frequently Asked Questions

There is no permit required to perform waterproofing of basement foundation walls in Toronto. Rock Basements can start water protection right away without waiting for approval from the city.

This work does involve changing or adding structural issues, therefore no permit is required.

Technically if there is no permit, there should be no city inspections, but it is not always the case.

Waterproofing itself does not require city official to confirm the quality of work, but work around it may need it.

For example if drains are installed or replaced during the same work, it has to be inspected by city.

Ministry of Labour or city representative may be called to ensure work is done in safely manner and there is no danger for excavation to cave in.

We can say with certainty that waterproofing jobs are not all similar. As a matter of fact they are all different due to number of factors that change the scope of work.

First of all there are two types of waterproofing the basement foundation. (Interior and Exterior).

Secondly every project varies with a terrain and depth of the basement, which we have to excavate to the footing before applying waterproofing system.

On top of everything, soil is different every time we dig. It can range from comfortable sand to extremely hard to hand dig clay with stones.

There are many situations in Toronto, when exterior waterproofing cannot be done or is just too complicated and expensive to implement.

The only solution available to protect the basement is to move inside the basement and waterproof the walls with installation of weeping tile along the perimeter of foundation on the interior part of the basement.

Lets start with saying that waterproofing warranty for interior and exterior work is 25 years.

Taking that into consideration we can say that interior waterproofing should last 40-50 years if done properly.

Assumption on exterior waterproofing is slightly less due to tears from soil movement and reaction to exterior weather. We still think exterior waterproofing should be good for at least 30-40 years.

Home builders and developers use not the best material and warrant basement from leaks only for 5-7 years with Tarion warranty.

Of course it all depends on size and difficulty of the project, but our average waterproofing project is 1 to 2 weeks.

Rock Basements assumes 15 linear feet to be excavated by hand during waterproofing every day and several days to protect the walls.

Complicated soil and deeper basements make it a little longer, but we try to get it done within above stated time.

Every outside project is weather dependent!

To speak about average waterproofing work we need to first understand average size basements in Toronto. Older house footprints are normally around 800 sq ft, but there is a full range from 400 sq ft to 1500 sq ft.

Thus exterior walls would be 40 + 20 + 40 +20 = 120 linear feet.

Average 800 sq ft basement Exterior Waterproofing costs $14 400 + HST

Average 800 sq ft basement Interior Waterproofing costs $9 600 + HST

Basement waterproofing is very fast and not dangerous process that does not involve structural change. under regular conditions you would not need to move out of the house to waterproof foundation walls.

Exterior waterproofing does not disturb interior basement and finishes at all. You can continue to live inside!

However, if you specifically want to do interior waterproofing and basement is currently occupied, they would need to vacate for around a week. It would be impossible to live around ongoing construction with dust, noise and demolition.

Another situation when home owners may need to temporary move out during the work is if waterproofing is done with other scope of structural or drain work inside the house that may disturb occupiers.

The waterproofing itself does cannot be applied for rebates, but work associated with it can help you get some of the money back in Toronto.

Overall subsidy in Toronto for flood protection is up to $3400 (more here).

Sump Pump Installation - Up to $1250 and 80% of costs.

Back Water Valve Installation - Up to $1750 and 80% of involved costs.

Foundation Drain (weeping tile - Up to $400 and 80% of involved costs.

If the water is already leaking through foundation wall into the basement, making a small patch is not going to solve the entire problem. It means that your foundation walls have started developing cracks and if one side is still dry, doesn't mean it will be good for the next few month or years.

We always recommend waterproofing entire basement to make sure it is fully covered with protected material and foundation walls are fixed. It is also beneficial to install weeping tile along perimeter to collect all the water going down the wall.

Approaching Steps for
Waterproofing Projects

Analyzing the Problem:

Before we begin anything, we want to analyze the actual problem and see what is causing water accumulation in the basement.

There could be many reasons for water to go go though the foundation wall and we want to be sure that our work is going to solve the issue.

After all we provide 20 years warranty on all our waterproofing projects and redoing work that has no effect is simply useless.

Sometimes the issues come from damaged water pipes, poor insulation and underground water directly from slab.

Honest Suggestions:

Our main goal is to help home owners with leaky basement walls with our work or basic suggestion. If after analyzing, we find an issue that can be solved without demolishing basement along perimeter to waterproof – we say exactly that.

Rock Basements has enough contracts throughout GTA and it is not in our interest to push clients for singing contracts when it is not necessary.

Making clients happy and keeping good reputation with client relationships in Toronto is more important than making a quick buck.


When problem is found and we agree with home owner to provide an estimate for the work, our project manager carefully calculates all involved scope of work.

Instead of simply stating obvious “Waterproofing of foundation” on proposal we want to explain and show all the steps that will be completed throughout the process.

After signing – estimate proposal becomes a legal agreement with exact price and explained steps of work to be taken. Additional work and costs can only be agreed with addendum to this estimate or a separate document.


Basement waterproofing is a relatively small in size project for our company and we should be able to schedule start within a week.

We understand the importance of basement protection from incoming water and try to give it a priority.

Rock Basements project manager can explain the steps in work with approximate timing. 

Starting time is always agreed with client for their convenience around construction.

Why Contract?
Rock Basements


Besides shopping around for lowers price, the company that you hire has to be experienced and professional within the trade.

Rock Basements has been around for over 15 years and our project managers know all ins and outs about waterproofing a basement in Toronto.

Take a look a our portfolio from various completed projects in Greater Toronto Area that left all clients satisfied with our waterproofing performance.

We are encouraged by basement waterproofing competition in Toronto and try to perform better every year.


One of the biggest factors that home owners tend to miss out on is hiring local company to do the work.

First of all working in the neighbourhood gives us a better idea of soil, potential problems, depth and even underground waters.

Therefore we can prepare better and know what to expect of the project.

Staying in the same area helps to keep the costs down. If our team doesn’t need to travel hours to work, the project will be estimated at lower price.

Fixed Cost:

There is nothing more frustrating in construction than having the cost increase during the waterproofing project.

Rock Basements prepares an estimate based on careful analysis of the problem and consideration of all client’s requests.

Unless the scope of work increases, our costs are going to stay the same until the end of the job.

Home owners may request additional work that will be estimated separated. It can be added to existing agreement or new proposal drafted.


Although no specific license is required to waterproof a basement, Rock Basement holds drain and general contractor licensing simply because we do structural work with drains under ground.

We are fully insured as a construction company and can take on small to large build projects.


Rock Basements keeps the waterproofing projects clean during work and we schedule a final clean up at the very end of work.

We want to satisfy our clients in work ethics and cleanliness.