Did you know that basement underpinning can increase your home’s value by up to 25% while also reinforcing its structural integrity? If you’ve noticed cracks in your foundation, uneven floors, or doors that won’t close properly, you might need underpinning to strengthen and stabilize your basement.

In this guide, we’ll cover everything you need to know about basement underpinning, including what it is, why it’s needed, and how the process works—especially if you own a home in Toronto’s shifting soil conditions.

As a contracting group specializing in basement underpinning in Toronto, we often get asked this simple question, “what is underpinning?”  Below is a brief answer to that question.

“Underpinning” is an industry term that’s generally used to describe reinforcing an existing foundation. This may be to shore-up a structure that was poorly built originally or has degraded over time, is subject to subsidence or land-slippage, or is being prepared to carry extra weight.  Underpinning is also performed when a homeowner wants to have their basement foundation dug out to increase the ceiling height of their basement.  This is also known as basement lowering.

What Is Basement Underpinning?

Basement underpinning is the process of reinforcing and deepening your home’s foundation. This is done by extending the foundation deeper into the ground or strengthening existing supports. The process is commonly used for:

  • Fixing foundation issues caused by soil movement, water damage, or poor construction.
  • Increasing basement height to create livable space, such as a finished basement.
  • Improving home value by adding square footage and reinforcing structural integrity.

Why Do Homes Need Underpinning?

If you’re unsure whether your home needs underpinning, here are some common warning signs:

Visible cracks in basement walls or floors
Uneven floors or sinking sections of the house
Doors and windows that stick or won’t close properly
Gaps forming between walls and ceilings
Moisture or water leaks in the basement

These issues often occur due to Toronto’s freeze-thaw cycle, which causes soil expansion and contraction, leading to foundation shifts over time.

Different Methods of Basement Underpinning

Not all homes require the same type of underpinning. The method used depends on factors like soil conditions, foundation structure, and the extent of foundation damage. Here are the four primary basement underpinning methods:

1. Mass Concrete Underpinning (Traditional Method)

🔹 Best for: Older homes with simple foundation structures.
🔹 Process: This method involves excavating small sections beneath the foundation in a phased approach and filling them with concrete. The new concrete reinforces the existing foundation, making it stronger and more stable.
🔹 Advantages:
✅ Cost-effective for minor foundation adjustments.
✅ Minimal disruption compared to other methods.
✅ Suitable for shallow foundations.
🔹 Disadvantages:
❌ Not ideal for homes with deep foundations or poor soil conditions.

2. Beam and Base Underpinning

🔹 Best for: Homes with uneven weight distribution or structural weaknesses in load-bearing walls.
🔹 Process: This method uses reinforced concrete beams to transfer the weight of the structure onto a newly built base below the existing foundation. The base provides additional stability while minimizing movement in weak soil.
🔹 Advantages:
✅ Provides superior structural reinforcement.
✅ Can be used in conjunction with mass concrete underpinning for extra stability.
🔹 Disadvantages:
❌ More complex and expensive than mass concrete underpinning.
❌ Requires detailed engineering calculations to ensure proper weight distribution.

3. Pile Underpinning

🔹 Best for: Homes with unstable soil conditions, deep foundations, or significant structural issues.
🔹 Process: Piles (either concrete, steel, or helical screws) are driven deep into the ground to reach stable soil layers. The building’s weight is then transferred onto these piles, preventing future settlement.
🔹 Advantages:
✅ Ideal for homes built on weak or shifting soil.
✅ Suitable for deep foundations or structures with heavy loads.
✅ Can be used in high-water table areas where other methods fail.
🔹 Disadvantages:
❌ More expensive due to specialized equipment and labor.
❌ Requires professional engineering assessment before installation.

4. Bench Footing (Alternative to Underpinning)

🔹 Best for: Homeowners who want to increase basement height without excavating beneath the foundation.
🔹 Process: Instead of digging under the foundation, concrete “benches” are built inside the basement along the perimeter walls. These benches provide additional structural support while allowing the basement floor to be lowered within the existing foundation walls.
🔹 Advantages:
✅ More affordable than traditional underpinning.
✅ Does not disturb the existing foundation, reducing structural risks.
✅ Faster construction process compared to other underpinning methods.
🔹 Disadvantages:
❌ Reduces usable floor space due to the concrete bench encroaching into the room.
❌ May not be as effective for homes with serious foundation issues.

Stages in the Process

If there was a single basement job not recommended for amateurs or the uninsured), then basement underpinning has to be the one. Get it right, and you’ll add significant value to your home. Get it wrong though, and you could end up damaging the fabric of your house.

Appoint a licensed structural engineer with a record of completed jobs, to prepare statutory documents and obtain approval for the job.

Appoint a basement-underpinning contractor who’s similarly experienced to complete the following work:

Toronto home underpinning

 

  • Remove a small section of the existing foundation to obtain access underground, and replace it with a load-bearing joist.

 

  • Excavate alternate strips to the required depth, and pour shuttered reinforced concrete beneath the exposed sections of foundation.

 

  • When the new foundations are completely cured, complete the balance of the basement underpinning.

 

  • Lay a new floor when everything is stable, and build out the interior of the extended space.

Cost-Benefit Analysis

Houses are valued in terms of living space. A new basement could therefore increase the value of your home by up to 10% – and you get more living space too. Basements are especially popular when it comes to extending homes, because they retain existing footprints, and seldom affect the neighbors.

However, you are effectively building your house “upside down” by adding the walls and floor when the roof’s up already. While the job’s in process the structural integrity of the entire building is compromised in the short-run. If it fails, then your new basement could end up costing you a whole lot more than it’s worth.

Is Basement Underpinning Worth It?

If you’re planning to finish your basement, improve your home’s structural stability, or increase its value, underpinning is a worthwhile investment. Not only does it expand your home’s living space, but it also ensures your foundation is safe and stable for years to come.

Get a Professional Assessment

If you’ve noticed signs of foundation issues, don’t wait! Contact Nusite Group today for a free consultation and expert advice on the best underpinning solution for your home.

As a business owner or property manager in the Greater Toronto Area, maintaining the structural integrity and safety of your building is a top priority. Water damage is one of the biggest threats facing commercial properties in our region, with the potential to cause extensive harm if left unchecked. Thankfully, being proactive with waterproofing can safeguard your property and significantly reduce long-term costs.

Understanding Water Damage Risks in Toronto

To appreciate the value of preventative waterproofing, it’s important to first understand the unique water damage risks that properties in Toronto face. Our city’s climate presents a perfect storm of conditions that can lead to water intrusion and the costly problems it brings.

The Freeze-Thaw Cycle

During Toronto’s cold winters, moisture that has seeped into tiny cracks and crevices freezes and expands. This freeze-thaw action gradually breaks apart concrete and masonry, creating bigger gaps that allow even more water to penetrate. Come spring, snowmelt and rain find their way into these damaged areas, leading to leaks and flooding.

Many property owners don’t realize there’s a problem until significant damage has already occurred. Foundation walls, parking garages, and other concrete structures are especially vulnerable to this cyclic damage.

Humid Summers

While our winters put stress on buildings, Toronto’s humid summers bring their own challenges. High humidity levels mean that building materials stay damp longer, increasing the risk of moisture-related problems like:

  • Mold and mildew growth
  • Wood rot and decay
  • Corrosion of metal elements
  • Deterioration of finishes

If your property lacks adequate waterproofing and ventilation, this excess moisture can accumulate unseen within walls, attics, and crawl spaces. Over time, it steadily eats away at your building’s structural integrity.

The Compounding Consequences of Water Damage

When water infiltration goes unchecked, it sets off a chain reaction of compounding problems that can quickly spiral out of control. What may start as a small leak can balloon into an overwhelming and extremely expensive disaster.

Structural Damage

Prolonged water exposure weakens fundamental building components like walls, floors, and support beams. In extreme cases, this damage can be so severe that it compromises the overall stability and safety of the structure.

Sagging floors, bulging walls, and shifting foundations are all red flags that water has taken a serious toll. At this stage, repairs are extensive and disruptive, often requiring major reconstruction.

Mold and Health Concerns

Damp, humid environments are ideal breeding grounds for mold and mildew. These fungi not only cause unsightly stains and musty odors but also pose health risks.

Inhaling mold spores can trigger allergic reactions, respiratory issues, and other illnesses, creating an unhealthy environment for your employees and customers. If mold takes hold, you may need professional remediation which adds even more expenses.

Disruption to Business Operations

Significant water damage often necessitates temporarily relocating so repairs can be made. This disruption to your day-to-day operations comes at a steep cost.

Productivity plummets as your team tries to work around the issue. In customer-facing businesses, you may need to shut down entirely, losing sales and damaging your reputation. Regaining this lost ground once you reopen is an uphill battle.

The Financial Fallout

By the time you add up emergency repair bills, mold remediation costs, lost productivity, and potential customer losses, the financial impact of water damage is staggering. It’s not uncommon for costs to soar into the tens or even hundreds of thousands of dollars.

Worse yet, your insurance may not fully cover the damage if it’s deemed to be the result of neglect or improper maintenance. The financial burden falls squarely on your shoulders.

A Proactive Solution: Preventative Waterproofing

The good news is, you can avoid this nightmare scenario by taking a proactive approach to waterproofing your property. Preventative waterproofing is all about identifying and addressing potential problems before they have a chance to escalate.

Assessing Your Property

A qualified waterproofing contractor will start by thoroughly assessing your building to pinpoint any areas of concern. They’ll look for issues like:

  • Cracks in the foundation or walls
  • Gaps around windows and doors
  • Pooling water near the structure
  • Malfunctioning gutters and downspouts
  • Effloresence or staining on concrete

This inspection gives you a clear picture of your property’s unique vulnerabilities so you can develop a targeted waterproofing plan.

Sealing and Coating

One of the core tenets of preventative waterproofing is sealing cracks and porous surfaces to create an impenetrable moisture barrier. This is typically accomplished by applying specially formulated coatings, sealants, and membranes.

For example, a polyurethane injection can be used to fill narrow cracks in a foundation wall, while a crystalline slurry may be applied to prevent water from seeping through concrete.

Enhancing Drainage

Proper drainage is critical for directing water away from your building. A waterproofing contractor will assess elements like your gutters, downspouts, and grading to ensure water is being effectively channeled away from the foundation.

Where needed, they may recommend upgrades like:

  • Installing new gutters and downspouts
  • Regrading the soil around the building
  • Adding French drains or catch basins

By promoting positive drainage, you reduce the amount of water that can pool around your property and find its way inside.

Ongoing Maintenance and Inspections

Preventative waterproofing is not a one-and-done deal. Regular inspections and maintenance are key to catching any new issues that pop up over time.

Your waterproofing partner can set up a schedule of periodic checks to nip small problems in the bud before they have a chance to escalate. They’ll also guide you on routine maintenance tasks like cleaning gutters and repairing caulking to keep your waterproofing measures in tip-top shape.

The Bottom Line Benefits

While there is an upfront cost to preventative waterproofing, it pales in comparison to the long-term savings and peace of mind it offers. By proactively protecting your property from water damage, you:

  • Extend the lifespan of your building by preventing premature deterioration
  • Avoid exorbitant emergency repair and remediation bills
  • Preserve the value and marketability of your property
  • Minimize disruptions to your business operations
  • Maintain a safe, healthy environment for occupants

In short, preventative waterproofing is an investment in the future of your property and your business.

Don’t Go It Alone: Why You Need a Trusted Waterproofing Partner

Waterproofing is not something you want to cut corners on or tackle as a DIY project. Proper waterproofing requires a deep understanding of building science, local climate considerations, and the latest technologies and techniques. A single misstep could leave your building vulnerable to costly damage.

For true peace of mind, it’s crucial to work with a reputable waterproofing contractor who has a proven track record serving commercial properties in the GTA. At Nusite Group, we’ve been providing expert waterproofing and foundation solutions for over 30 years.

Our team takes a consultative approach, working closely with you to understand your property’s unique needs and create a customized solution. With services ranging from crack injection and sealant application to full building envelope restoration, we have the expertise to protect your property for the long haul.

Don’t Wait for Disaster to Strike

Too often, businesses put off waterproofing until they’re facing a catastrophic leak or crumbling foundation. By then, the damage is done and the costs are sky-high. Don’t let this be your story.

By embracing preventative waterproofing today, you can safeguard your property, avoid financial disasters, and rest easy knowing your building is prepared to stand strong for years to come.

Ready to take the first step toward protecting your property? Contact Nusite Group today to schedule a consultation. Our experts are standing by to help you develop a customized waterproofing plan tailored to your needs. Let us give you the peace of mind you deserve.

As a property manager in the Greater Toronto Area (GTA), maintaining the integrity of your building’s envelope is critical for protecting your investment, ensuring tenant comfort, and avoiding costly repairs down the line. The building envelope, which includes the roof, walls, windows, and foundation, serves as the first line of defense against the elements. In the GTA’s variable climate with cold snowy winters, hot humid summers, and plenty of rainfall, a compromised building envelope can quickly lead to serious issues.

Catching building envelope problems early is key to minimizing damage and repair costs. But what exactly should you be looking out for? Here are some of the most common early warning signs that your building envelope may be starting to fail:

1. Water Stains or Leaks

One of the most obvious signs of potential building envelope issues is the appearance of water stains on walls, ceilings, or around windows and doors. In the GTA’s climate, repeated freeze-thaw cycles in winter can cause particular problems, with melting snow and ice finding its way into small cracks and openings. Pooled water on a flat roof is another warning sign that drainage issues may be putting strain on the building envelope.

What starts as a small stain or occasional drip can signal the beginning of a much larger problem, so never ignore water where it shouldn’t be. Get a professional in to evaluate the source and extent of the issue.

2. Cracks in the Facade

While small hairline cracks in stucco, brick, or stone may not be cause for major concern, larger cracks, especially those that appear suddenly, could point to a building envelope problem. A shifting foundation, damage from freeze-thaw cycles, or moisture getting in and breaking down materials can all cause noticeable cracks to form.

Keep an eye out for cracks larger than 1/8 inch wide, horizontal cracks (which can signal serious structural issues), and those that seem to be growing rapidly. You’ll want to call in the experts to determine the underlying cause and appropriate repairs.

3. Bulging or Bowing Walls

Walls that are bulging, bowing, or pulling away from the building are a major red flag that warrants immediate investigation. This could be due to water infiltration breaking down the wall assembly materials, hydrostatic pressure from oversaturated soil, or foundation settlement issues, among other causes.

If you notice any pronounced inward or outward displacement of a wall, contact a specialist in building envelope solutions right away to diagnose the issue and recommend a repair plan. Waiting will likely only lead to more severe and costly problems.

4. Spike in Energy Bills

A more subtle sign that your building envelope may be compromised is an unexpected increase in heating or cooling costs. The GTA’s hot, humid summers put air conditioning systems to work, while the cold winters mean cranking up the heat. If your HVAC system seems to be working overtime compared to previous years, it could be due to air leaks or insufficient insulation letting that conditioned air escape.

While many factors can influence energy bills, it’s worth taking a closer look at your building envelope if you suspect it may be the culprit. An energy audit can help identify areas where your building may be leaking air.

5. Mold or Mildew Growth

Finally, the appearance of mold or mildew inside the building is almost always a sign that moisture is getting in where it shouldn’t. While mold can be a serious indoor air quality issue on its own, it’s also a symptom of an underlying building envelope problem that needs to be addressed.

Mold thrives in damp environments, so its presence signals that water is infiltrating the building somewhere, likely through gaps or leaks in the envelope. A mold remediation specialist can help clean up the immediate mold issue, but you’ll want to bring in building envelope experts to correct the water intrusion problem itself.

Get Professional Help Early

For property managers in the GTA, staying on top of building envelope maintenance is an essential part of the job. Knowing the early warning signs to watch for, from obvious water stains to more subtle energy bill spikes, can help you catch small issues before they have a chance to become major headaches.

If you do suspect a building envelope problem, don’t wait to bring in professional help. Working with experienced building envelope contractors who understand the unique challenges of the GTA climate and building codes can help you identify and correct issues quickly. At Nusite Group, our team has over 30 years of experience providing expert waterproofing and building envelope solutions across the GTA. Contact us today to learn more about how we can help keep your building safe and watertight for the long haul.