Basement Crack Repair in Toronto

Water in your basement almost always starts the same way: a crack. In the wall. In the floor. At the joint where the wall meets the floor. And once water finds a path, it uses it — every heavy rain, every spring thaw.

VMB Group repairs leaking basement cracks across Toronto and the GTA. Most repairs are completed in a single visit. All work is warranted.

What Is Basement Crack Repair?

Basement crack repair covers the diagnosis and sealing of cracks that are allowing water into your basement — whether in the walls, the floor, or at the wall-floor joint. The goal is to permanently stop water entry through the crack and address the underlying cause wherever possible.

This is different from structural foundation repair, which deals with cracks that affect the load-bearing integrity of the wall. Most basement cracks that let in water are non-structural — they don't threaten the wall itself, but left unsealed they cause moisture damage, mold, and deteriorating air quality over time.

If you're not sure whether your crack is structural or just leaking, we'll tell you at the free inspection. The two require different repairs, and we won't recommend the wrong one.

Signs You Need Basement Crack Repair

You can see it:

A visible crack in a basement wall — vertical, diagonal, or stair-step pattern
A crack in the basement floor, especially one that’s damp or has a white mineral residue around it
A gap or crack at the joint where the basement floor meets the wall

Water is telling you something:

Water seeping in during or after heavy rain
A damp patch on the wall that appears seasonally — after snowmelt or spring rain
Efflorescence: white chalky deposits on the wall where water has evaporated through
Musty smell in the basement, especially in spring and fall
Moisture or condensation on the lower portion of the wall that doesn’t match the rest of the room

It's been there a while:

A crack you’ve had for years and “kept an eye on” that has now started leaking
Rust staining around a crack (water carrying iron minerals from the soil)
Staining on drywall or framing near a wall crack

Types of Basement Cracks We Repair

Wall cracks — vertical

The most common type. Usually caused by concrete shrinkage as it cures. Non-structural in most cases but frequently allow water in, especially as the crack widens slightly over years of freeze-thaw cycles. Repaired with polyurethane foam injection (for wet or active cracks) or epoxy injection (for dry cracks).

Wall cracks — diagonal

Usually caused by minor differential settlement — one part of the foundation shifting slightly relative to another. Often appear near window or door corners. Most are non-structural. Repaired with injection.

Stair-step cracks (in block foundations)

Follow the mortar joints in older block or stone foundations. Common in Toronto homes built before 1960. Can allow significant water entry as mortar deteriorates. Repaired with injection and mortar repointing as needed.

Floor cracks

Cracks in the basement concrete floor slab, often caused by soil shrinkage beneath the slab or minor settlement. When water appears through a floor crack, it's usually groundwater under pressure — the water table is pushing up. Repaired with polyurethane injection and, in recurring cases, addressed with a drainage channel and sump pump.

Wall-floor joint (cove joint)

The seam between the basement floor slab and the foundation wall is a common water entry point — the two pours of concrete don't bond perfectly and the joint can open over time. Water enters from soil pressure outside. Repaired with drainage channel installation or interior waterproofing along the perimeter.

Note:

Horizontal wall cracks are a different category — they indicate structural wall movement, not just water infiltration. If your crack runs horizontally, it needs structural foundation crack repairs, not injection. We'll identify this at the inspection.

Repair Methods We Use

Polyurethane foam injection

The standard method for active, wet, or leaking wall cracks. Polyurethane is injected through ports placed along the crack. It expands as it cures, conforming to the exact shape of the crack — including irregular voids — and creating a waterproof seal that remains flexible with seasonal wall movement. Works even in wet conditions. Most jobs: 1–3 hours.

Epoxy injection

For dry, non-structural vertical cracks where a rigid, high-strength seal is needed. Epoxy bonds the concrete and restores tensile strength across the crack. Not suitable for wet or actively leaking cracks (moisture prevents proper bonding). Most jobs: 2–4 hours.

Floor crack injection

For floor cracks with occasional moisture. Polyurethane is injected to seal the crack from below. For floor cracks with persistent water entry (groundwater under pressure), a drainage channel routed to a sump pump is a more reliable long-term solution.

Interior drainage channel + sump pump

For wall-floor joint leaks or floor cracks where water entry is consistent. A channel is cut into the perimeter of the floor slab, a drainage pipe is installed, and water is directed to a sump pit and pumped out. This doesn't seal the crack but manages the water permanently. Often the right solution when the source of water is groundwater pressure rather than a specific crack.

Basement Crack Repair Cost in Toronto

Repair type	Typical cost
Polyurethane injection (single wall crack)	$500 – $1,200
Epoxy injection (single dry crack)	$500 – $1,100
Floor crack injection (single crack)	$400 – $900
Multiple cracks (3–5 in same visit)	$1,200 – $2,800
Wall-floor joint sealing (per linear foot)	$80 – $150/lf
Interior drainage channel + sump pump	$4,000 – $8,000+

What drives the cost up:

Number of cracks
Length and depth of each crack
Whether the crack is active (wet) vs. dry
Whether the root cause (drainage, weeping tile) needs to be addressed at the same time

All estimates are free, written, and no-obligation.

Can I Repair a Basement Crack Myself?

For a narrow, dry, non-structural vertical crack that isn't leaking, a DIY polyurethane or epoxy injection kit (available at hardware stores for $50–$100) can be effective. The technique is straightforward and kits come with instructions.

When not to DIY:

The crack is actively leaking or wet — DIY kits don't bond reliably in wet conditions

The crack is horizontal — that's a structural issue requiring professional intervention

The crack is wider than ¼ inch, or has grown since you first noticed it

You've tried sealing it before and water came back

You don't know what type of crack it is

If you're uncertain, a professional assessment costs nothing and gives you a clear answer. A DIY repair on a crack that needed something more can give false reassurance while the problem continues behind the sealed surface.

Why Basement Cracks Let Water In

The mechanism is straightforward: Toronto's soil holds and releases moisture with every rain and every season. As clay soil gets wet, it expands and pushes against the foundation wall. When the soil dries, it pulls away — and the gap it leaves allows water to pool at the base of the wall. Repeat this cycle over 20, 30, 50 years and even small shrinkage cracks in concrete begin to widen.

Key contributors in Toronto specifically:

Leda clay soil — absorbs moisture and expands significantly, applying lateral pressure to walls and forcing water toward any opening
Failed weeping tile — most Toronto homes built before 1980 have clay weeping tile that has deteriorated. Without functional drainage at the footing, water has nowhere to go except through the wall
Grading issues — if the ground around your home slopes toward the foundation rather than away from it, every rain directs water at the wall
Spring snowmelt — a rapid snowmelt in Toronto can saturate the soil faster than it can drain, creating hydrostatic pressure against the foundation for weeks

Our Process

1. Free inspection

We look at every crack — in walls, floor, and at joints. We identify the type, assess whether it's structural or non-structural, and check for signs of active water entry or prior sealing attempts.

2. Clear diagnosis

We tell you what you have, why it's happening, and what the repair options are. If it's a simple injection job, we say so. If it needs more, we explain why.

3. Written estimate

You get a written price before any work begins.

4. Same-day repair (most cases)

Most basement crack injection jobs are completed the same day as the estimate, or scheduled within a few days. The work is minimally invasive — no excavation, no major disruption to the home.

5. Warranty

All crack repair work is warranted by VMB Group.

Service Area

Toronto · Etobicoke · North York · Scarborough · East York · Mississauga · Brampton · Hamilton · Burlington · Oakville · Vaughan · Markham · Richmond Hill · Pickering · Ajax · Whitby · Guelph · Cambridge · Kitchener · Waterloo

Frequently Asked Questions (FAQ)

Can you fix a basement crack from the inside?

Yes — for non-structural cracks, interior injection (polyurethane or epoxy) is effective and permanent. The material is injected from the inside and fills the crack through its full depth to the exterior face of the wall. You don't need excavation. For structural cracks — especially horizontal ones — interior injection may not be sufficient on its own.

What is the best way to repair a crack in a basement wall?

It depends on the crack type. For a dry, vertical, non-structural crack: epoxy injection. For a wet or leaking vertical crack: polyurethane foam injection. For a horizontal crack: structural assessment first — injection alone won't address the underlying wall movement. We match the method to the crack, not the other way around.

When should basement cracks be repaired?

As soon as water entry is observed, or as soon as a crack starts growing in width or length. Non-structural cracks that are dry and stable can be monitored for a period, but once water entry begins or the crack widens past ¼ inch, repair should happen promptly. Delayed repair allows moisture to reach framing, insulation, and drywall — the secondary damage often costs more than the crack repair itself.

How long does basement crack repair take?

Most injection repairs are completed in 2–4 hours. Floor crack injection is similar. Interior drainage channel installation takes 1–3 days depending on the perimeter length.

Will the crack come back after repair?

A properly injected crack won't re-open at the same location. However, if the underlying cause — soil pressure, failed drainage, poor grading — isn't addressed, new cracks can form elsewhere. We'll flag any drainage issues we observe during the inspection.

Is basement crack repair covered by home insurance?

Gradual water damage from slow-seeping foundation cracks is typically not covered. Sudden water damage from a specific event (a burst pipe undermining the footing, for example) may be. We can provide documentation for insurance claims where applicable.

How much does basement crack repair cost in Toronto?

A single injection repair typically costs $500–$1,200. Multiple cracks in the same visit are usually more cost-effective per crack. We provide free written estimates — crack repair costs vary enough by type and severity that accurate pricing requires seeing the crack in person.

Related Services

Structural wall cracks: If your crack is horizontal, or wider than ¼ inch, or the wall appears to be bowing — Foundation Crack Repair →
Widespread water entry: If water is coming in at multiple points or along the full perimeter — Interior Waterproofing →
Drainage at the source: Fix the soil drainage that’s driving water toward the wall — Weeping Tile Installation →
Ongoing water management: Sump Pump Installation →

Basement Crack Leaking? We Can Fix It.

Most basement crack repairs are done in a single visit. VMB Group will assess the crack, tell you exactly what's causing it, and repair it right — backed by a warranty.