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Products & Services

Mold Services
Dust Mites Control
Mold Spores
Mold Prevention
Dry Rot & Brown Rot

Basement Repair Services & Products
WaterGuard Interior System
DryTrak Drainage Channel
TrenchDrain Drain Grate
IceGuard Discharge Line
FlexiSpan Wall Crack Repair
Polyurethane Crack Sealing
WellDuct Window Drainage
BrightWall Waterproof Panels
ThermalDry Wall Barrier
Basement to Beautiful Pre-Finishing Wall Insulation Panels
Drain Tile Installation
SuperSump Pump System
TripleSafe Pumping System
UltraSump Battery Back Up
SaniDry Dehumidifier

Crawl Space Repair Services & Products
CleanSpace Encapsulation Vapour Barriers and Liners
Turtl Access Hatch
EverLast Crawl Space Doors
SaniDry CSB Dehumidifier
SmartDrain Water Drainage
SilverGlo Wall Insulation
TerraBlock Floor Insulation
SmartSump Sump Pump
WallCap Block Wall Sealer
SmartVent Flood Vents

Foundation Repair Services & Products
Push Pier Underpinning for Settlement, Foundation Leveling, Sinking Foundation Repair
Structural Repair
Geo-Lock Wall Anchors
Geo-Lock Helical Anchors
PowerBrace Bowed Wall Repair
CarbonArmor Fiber Wall Repair
SmartJack Crawl Space Support
Slab Pier Repair
PolyLevel Concrete Lifting & Leveling
ShotCrete Wall Restoration

Company Awards
Clarke Basement Systems has been awarded the HomeStars Best of 2016 award which we are very proud of.... [Read more]
The Community of Markham has chosen our business as the winner of the annual Markham Economist & Sun Reader’s Choice... [Read more]
Ratings are calculated based on consumer-review websites and blogs, social networks, business rating services and other award information to determine... [Read more]
More Awards

Your Certified Thornhill, ON Foundation Repair & Basement Waterproofing Contractor

Well done - all 'round!...
Happy Customers Surrounding Thornhill, ON
Work Requests

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Reviews From Thornhill
Testimonials From Thornhill
It's exactly what we wanted. We will definitely recommend your company. Thanks again!
Testimonial by Bethany W. from Thornhill, ON

Basement Waterproofing & Crawl Space Repair in Thornhill, Ontario

Water in the basement or crawl space leads to mold, rot, musty odors and structural issues. It also leads to a reoccurring headache for you. Luckily, our trained experts are available to permanently fix the problem.

We will properly install a hidden drainage system in your Thornhill basement and completely encapsulate your crawl space with CleanSpace vapor barrier. We are here to solve the problem for you.

Why Choose Us?
  • Lifetime Warranty on all Perimeter Waterproofing Systems
  • 25-year Warranty on Crawl Space Encapsulation Systems
  • Sump Pump Installation, Repair & Replacement
  • Basement, Crawl Space & Spray Foam Insulation
  • Crawl Space & Basement Dehumidifiers
  • Hundreds of Satisfied Customers

Structural & Foundation Repair in Thornhill

Foundation problems destroy your Thornhill home’s value and can be dangerous. Our in-house team of structural and geo-technical engineers are here to help. We design and install the right solution and usually have the project finished in less than a week. You will have peace of mind as we provide a 25-year written warranty against defects on our foundation products.

We Fix
  • Bowing Walls
  • Sagging Floors
  • Stair-Step Cracks
  • Tilting Chimneys  
  • Foundation Cracks
  • Garage Slabs   
We Use
  • Wall Anchors
  • Slab Piers
  • I-Beam Wall Braces
  • Helical Deck Piers
  • Sticking Windows
  • Underpinning

PolyLevel™ Concrete Leveling & Lifting

The sunken and cracked concrete around your Thornhill home is both an eyesore and a safety hazard. It is also likely to get worse, but we can fix it for you.

Our experts use PolyLevel, a superior polyurethane foam. Small holes are drilled in the concrete, the foam is injected and the expanding foam lifts the concrete. The majority of contractors you will call use mudjacking instead of foam. Mudjacking is heavier, require larger holes in the concrete and does not last as long as PolyLevel. Call us today to learn more.

We Fix
  • Cracked Driveways
  • Uneven Patios
  • Sinking Sidewalks      

  • Uneven Concrete
  • Sunken Pool Decks
  • Highway & Commercial Issues


Case Studies From Thornhill
Contractor was doing a renovation for a customer who had a very wet basement. There had been a wood sub floor which had totally rotted and needed to...
News & Events From from Thornhill
Waterproofing your basement keeps it dry and warm and creates a healthier environment in your home. Before you finish your basement, you should make sure it is waterproofed to avoid damage to your floor, walls, furniture and belongings.... [Read more]
You can repair basement leaks yourself, but you will need to know a bit about home renovations. That's because a basement leak can have many different causes or sources and each one requires different skills to repair.... [Read more]
Water damage in your basement? It's problem that needs to be taken care of right away. If not, it will continue to get worse and can become costly - and unhealthy - very quickly.... [Read more]
Work Requests From Thornhill, ON
Brookmill Drive in Thornhill
We have a leak on one of our basement walls. We are not sure why. Probably need an estimate.
Holm Cres in Thornhill
Rain water is leaky through the foundation on one side of the house.
Marsnow Drive in Thornhill
I need to lift 5 concrete slabs around the pool to level the deck.
Aileen Road in Thornhill
Water is penetrating in one corner basement room and after heavy quick rainfall, water also enters from a basement wash room window when window hole is filled with surface runoff.
Ramblewood Lane in Thornhill
Crack in foundation - crack on inside of garage. Two other cracks appearing but has not affected inside garage.
Serving the following Thornhill, ON postal codes
L3T 0A1, L3T 0A2, L3T 0A3, L3T 0A4, L3T 0A5, L3T 0A6, L3T 0A7, L3T 0A8, L3T 0A9, L3T 0B1, L3T 0B2, L3T 0B3, L3T 0B4, L3T 0B5, L3T 0B6, L3T 0B7, L3T 0B8, L3T 0B9, L3T 0C1, L3T 0C4, L3T 0C5, L3T 0C6, L3T 0C7, L3T 0C8, L3T 0C9, L3T 0E1, L3T 0E2, L3T 0E3, L3T 0E4, L3T 0E5, L3T 0E6, L3T 0E7, L3T 1A1, L3T 1A2, L3T 1A3, L3T 1A4, L3T 1A5, L3T 1A6, L3T 1A7, L3T 1A8, L3T 1B1, L3T 1B2, L3T 1B3, L3T 1B4, L3T 1B5, L3T 1B6, L3T 1B7, L3T 1B8, L3T 1B9, L3T 1C1, L3T 1C2, L3T 1C3, L3T 1C4, L3T 1C5, L3T 1C6, L3T 1C7, L3T 1C8, L3T 1C9, L3T 1E1, L3T 1E2, L3T 1E3, L3T 1E4, L3T 1E5, L3T 1E6, L3T 1E7, L3T 1E8, L3T 1E9, L3T 1G1, L3T 1G2, L3T 1G3, L3T 1G4, L3T 1G5, L3T 1G6, L3T 1G7, L3T 1G8, L3T 1G9, L3T 1H1, L3T 1H2, L3T 1H3, L3T 1H4, L3T 1H5, L3T 1H6, L3T 1H7, L3T 1H8, L3T 1H9, L3T 1J1, L3T 1J2, L3T 1J3, L3T 1J4, L3T 1J5, L3T 1J6, L3T 1J7, L3T 1J8, L3T 1J9, L3T 1K1, L3T 1K2, L3T 1K3, L3T 1K4, L3T 1K5, L3T 1K6, L3T 1K7, L3T 1K8, L3T 1K9, L3T 1L1, L3T 1L2, L3T 1L3, L3T 1L4, L3T 1L5, L3T 1L6, L3T 1L7, L3T 1L8, L3T 1L9, L3T 1M1, L3T 1M2

our service area