What is the difference between interior and exterior waterproofing?

We provide both interior and exterior waterproofing solutions.  Be aware that some companies only employ an interior solution, regardless of the actual problem. These aren’t true waterproofing companies.  They may try and steer you towards a solution that they are selling rather than a solution that is best for you and your home.

The Only Reasons To Use Interior Waterproofing

  • This is not waterproofing, it is water management, the water still comes through the wall, and we are not protecting from frost or erosion.
  • We will choose to work from the inside of your home when excavating is not possible or the landscaping/exterior utilities do not allow us to.
  • When you lower your basement, it is always recommended to install an interior system as your old system outside is now too high relative to your basement floor.
  • If the wall is strong and sound to support an interior repair we will install one if you choose this option.
  • Interior methods are also used when you have a small repair; you can use this to manage small leaks to temporarily manage them.
  • It is best used on concrete or structurally sound walls.

Why Do We Work From The Exterior?

  • Working from the outside in fact waterproofs the area we work in.
  • It stops water from entering the home protecting it from frost and foundation erosion.
  • This method structurally ensures the life of the wall and the building it supports.
  • Basements are not waterproofed to begin with, Ontario Building Code only calls for damp proofing and this minimum standard is usually all that builders apply, often times not very well. (waterproofing membranes are like sun-block, it stops 100% of the sun and damp proofing is like sun-screen, it does not protect 100% and allows amounts of rays through).
  • When we work on the exterior we are able to repair large voids gaps or cracks that may be the source of the problem versus putting up a membrane inside to manage the flow.
  • When working on the exterior we have access to the wall to apply proper waterproofing coatings that stay flexible and move with the wall, preventing future leaks.
  • Exterior work allows us access to your weeping tile, we can replace the old weeping tile in the areas we work and camera the rest to ensure No Surprises when it comes to your most important drain system. We actually can confirm if your system is clear, may need work, and accurately give you a time frame to prepare for a full perimeter system.
  • When your wall is cinder-block, stone, bricks or aging concrete it is best to work from the exterior when possible to ensure the wall does not erode and remains structurally sound.

What is that white powdery stuff on my walls?

What you see there is efflorescence. It often occurs on masonry construction, particularly brick and cement block, when water moving through a wall or other structure, or water being driven out as a result of the heat of hydration as cement stone is being formed, brings salts to the surface that are not commonly bound as part of the cement stone. As the water evaporates, it leaves the salt behind, which forms a white, fluffy deposit, that can normally be brushed off. The resulting white deposits are referred to as “efflorescence” in this instance.

Can I fix my foundation crack by injecting it with epoxy, urethane or other compound?

Vertical Foundation cracks are the most common cause of leaks in your basement. They are generally a result of structural shifting or something done after the fact causing pressure on the wall from the exterior like a tree (or simply improper rebar installation, bad concrete mix, bad weather when pouring etc.).  A crack in your foundation can be from a number of reasons, that’s why it’s important to have it properly inspected by a trained professional.  If your foundation has a horizontal crack, it could signify something structurally wrong and may need proper attention from a structural professional.

Cracks are most common on the bottom corner of basement windows formed into the concrete or on new homes (under 2 years when all the settlement happens). Of all the types of walls; concrete walls are the only type of wall that can be injected to stop the water. However there are many drawbacks to installing this type of system and after many years in the business, we have seen plenty of failed injections.

When it comes to injecting your foundation with any sort of resin/epoxy/urethane type kit you should understand a few things:

  1.       You cannot inject any other type of wall other than a concrete wall limiting you if you have a stone, block or brick wall (you cannot inject these types of walls)
  2.      Injections without proper protective masks and personal protection can be harmful to you, most installers may not take proper precautions (mixing resins or using products on the interior of your home to form an expanding compound can produce harmful fumes)
  3.      Epoxy is a mix between a resin and a hardener this can lead to a few issues like:
  •   This liquid, if not hardened fast enough, can seep into surrounding areas and leave voids in the crack being repaired (especially at the top of a crack as like anything, gravity will play its course)
  •  This may lead to an irregular application causing your problem to recur even though it looks perfect from the inside
  •     Re-injecting a previously injected crack is borderline impossible as the voids, gaps cracks and pockets in the previous resin may not be filled properly and we cannot see them
  •     If the crack is actively leaking, the water entering may not allow the product to work properly (just like we cannot apply waterproofing materials to wet walls)
  •     The foundation shift causing the crack may move further, more often than not creating a crack in the crack injection (the most common reason for it to fail)
  •   Most products can only handle a gap no greater than 1/16th of an inch
  •   If the crack expands once injected, only a proper exterior solution will stay flexible and move with the wall shift keeping a seamless membrane in tact (ie. The Aqublock and Yellow-Jacket process we use)

Even with the best polyurethane polymer compounds that promise to stay flexible and work with the shift, they cannot guarantee 100% success. Most injection companies will up sell a secondary barrier channeling water under the floor “in-case” the injection fails (that shows true confidence in the product!)


Everything in construction is frost protected, Yes, even the exterior waterproofing has a drainage board giving the ground something to freeze to protect the wall, tar, and mesh system in place!

What is important with foundation cracks is to determine if it is a major structural issue. Is there already an injection there that has failed? What type of product are they injecting? Most exterior solutions and products applied are not that much more costly than an interior injection and come with a proven track record and warranty. To speak with a representative about injecting versus any other method we would be happy to explain this to you in a free consultation. Contact us here to set an appointment.

I got a quote to use Blueskin, is this the right application for my wall?

Blueskin is a great product. It is used in many ways all over the commercial and residential construction industry. We use this Blueskin WP 200 in very smooth or perfect concrete walls. You can use it underground as a waterproofing membrane and achieve great results but there are better solutions offered by the same company. Since a majority of our work is re-doing old damp proofing its often the surfaces we work on are never perfectly smooth. A trowel or spray applied coating (ie. Aquablock 720-38 for example) provides a better application and adhesion to an irregular wall everytime.

What membranes do you use? Do you sell any of your products?

Each membrane we use is from the Henry, or DMX company line of waterproofing products. The most common product we apply is Aquablock series membranes, DMX weeping tiles and DMX drain boards. We have no vested interest in the materials we use so we source the best products we can use on your home.


How long have you been in business?

We have been in the construction business since 1979 and have been waterproofing and repairing foundations since our inception. This is a family owned and operated business and is not a franchise.  We are lifelong residents of Toronto and we are proud of our reputation in the industry. We have maintained a great record with our clients and have proudly maintained a  A+ BBB rating for the life of our business.

You can find out more about the people behind Nusite on our About Us page.

Do you offer a warranty with your work?

Most consumers focus on the length of the warranty (ie. 15 years, 25 years or even a lifetime!). What you need to know is what it actually guarantees. Most exterior building products, even the most expensive ones do not have a lifespan of more than 10 years so be careful when making a decision based on length of warranty. (think of roofing, what shingles last a lifetime?).  Many lifetime and extended warranties on waterproofing will contain special clauses that will make it difficult for you to ever make an actual claim.

Instead of asking how long the warranty is for, ask how many warranty calls you have had in the duration of your business. We operate on less than a 1% call back rate on over 1,700+ homes waterproofed since 2010.

You should be asking about the materials, their quality and the processes that are used! This will ensure you do not compare our standard 15 year warranty to a lifetime warranty when the grades of “waterproofing” products can differ immensely. We only use Canadian made products from Bakor (Aquablock, Blueskin, and CM-100 Series materials). These systems are the best you can buy and come with a proven track record in the waterproofing industry.

All of our customers receive a written and signed certificate before the job is complete outlining any outstanding issues (ie. Clean up, lay gravel etc.). This certificate will act as your warranty card and is fully transferable to any new homeowner.

What can I expect from when I schedule an estimate?

When you call our office you will be dispatched to one of the owners of the business.  We handle each and every call personally. Our sales representatives are not assertive, we understand a leak is a sensitive issue and strive to educate you on your issue versus using “arm twisting” sales tactics.

Once you have a free estimate and inspection booked, we will come to your home and make our assessment of your situation. Our representatives are professionals and will be dressed in Nusite attire on the day of the estimate.

We will sit with you and educate you on the type of wall you have and how certain solutions (ie. The drawbacks of a block or stone-wall versus concrete) should be chosen and create a realistic plan based on your budget and needs.  We will explain the repair process and answer and questions you may have.

Through the use of technology, building code, and building envelope theory we will explain why you are seeing the symptoms that prompted your call and confirm it with the use of tools such as moisture meters designed to test water % in drywall, plaster, wood, brick and concrete/stone.

Once we have confirmed why the water is entering your home, we will leave you with a comprehensive package including a written estimate, a detailed process sheet, and a sample warranty certificate.

Once we complete your project and everything is to your liking, the job is signed off and your warranty is now in full effect.

Can you provide references for your work?

Yes we can! We have many online reviews you can read on Homestars.com. We also have many clients you can speak to upon request. We will always ask for feedback on our work so we can continually improve our process and customer service.

What are your certifications?

We have educated ourselves through industry provided training courses and bring proper tools to scope the source of your water problems.  We have developed an effective waterproofing system over the last 30 years and  as part of repairing any leaks, we ensure that the root cause of the leak is moved away from your home and disposed of.  In other words, we fix the leak and make sure it doesn’t happen again. We are IICRC certified to use moisture meters, air humidity meters, weeping tile and drain cameras to determine the causes of water infiltration depending on the situation.

We can show you how thermal imaging may or may not show you what you need to see and explain how Improper Calibration can make anything look wet, so make sure you speak with an expert.

We are also proud members of:

  • The Ontario and Canadian Home Builders Association
  • The Toronto Construction Association
  • The Infrastructure Health and Safety Association
  • BILD – Building Industry and Land development Association
  • Renomark
  • Indoor Air Quality Association
  • The Better Business Bureau