Basement & Foundation Waterproofing in Markham

Basement & Foundation Waterproofing

We help Markham homeowners stop leaks, control moisture and protect foundations in areas like Unionville, Markham Village, Cornell, Milliken, Greensborough and Box Grove. From exterior waterproofing membranes to interior drainage and sump pumps, A&A Masonry designs waterproofing systems that fit your house, soils and local weather.

Crawlspace with sealed concrete floor, perimeter drainage channel, exposed framing, insulation and ductwork

Basement and crawlspace waterproofing

Worker installing a dimpled drainage membrane and perforated drain pipe beside an exposed foundation wall

Exterior foundation membranes and drainage

Worker applying sealant along a vertical crack in a concrete basement wall

Crack repair, sump pumps and leak diagnostics

Waterproofing For Markham’s Ravines, Clay Soils And Mixed Age Homes

Markham combines historic streets in Unionville and Markham Village with busy corridors along Highway 7, 404 and 407 and newer subdivisions in Cornell, Greensborough, Wismer and Box Grove. Many homes sit near ravines, stormwater ponds and the Rouge River system. Clay and mixed soils, dense paving, walkout basements and sloped lots can all push water toward your foundation. Over time that pressure shows up as damp walls, musty smells, white mineral deposits, peeling paint or cracks that slowly grow.

A&A Masonry does more than cover stains with paint. We follow how water actually moves around your home. That includes roof drainage and downspouts, driveways and walkways, patios and side yards, grading, window wells, footing drains and every crack in poured concrete, block or stone walls. Then we recommend exterior, interior or combined waterproofing so you are managing water at the source instead of waiting for it to appear on the floor.

Whether your home is in Unionville, close to historic Main Street, in Markham Village, near Highway 7 and Warden, in Milliken or Steeles East, in Cornell or Greensborough, or in newer communities near Box Grove and Donald Cousens Parkway, our goal is the same. We help keep water out of your basement and protect the masonry that carries the load of your home.

Common Waterproofing Issues In Markham

Water seepage at the base of the basement walls after heavy rain
Damp or musty basements in older block or stone foundations
Cracks in poured concrete or block walls that leak
Leaking cold rooms and front porches near driveways or walkways
Window wells that fill and leak on ravine or sloped lots
Homes without up-to-date footing drains or reliable sump systems

Waterproofing Services In Markham

No two Markham properties are the same. We begin with a detailed inspection and drainage review, then match you with the right mix of exterior waterproofing, interior drainage, crack repair and sump systems so the solution fits your foundation type, lot and long term plans.

Crew installing a dimpled waterproofing membrane over a coated exterior foundation wall

Exterior Foundation Waterproofing

When access allows, the most complete way to protect a foundation is from the outside. We excavate to the footing, clean the wall, repair cracks and voids, apply a modern waterproofing membrane and add drainage board and stone backfill. This helps keep water away from the wall so it never reaches your basement in the first place.

Workers install DELTA-MS dimpled membrane along basement walls and floor

Interior Basement Waterproofing

Decks, additions, close neighbours, retaining walls or tight side yards can make exterior excavation difficult. In those cases, we cut a trench along the inside perimeter, install an interior drainage channel and connect it to a sump pump. This collects water at the base of the wall and moves it to a controlled discharge point instead of letting it force its way into your living space.

Workers repair a vertical foundation crack beside a brick wall in an excavated work area

Foundation Crack Repair

Cracks in foundation walls are common in Markham, especially near driveways, garage corners and downspout discharge points. We first look at why the crack formed, then seal and reinforce it using appropriate methods such as epoxy or polyurethane injection, patching and reinforcement so the repair lasts and is less likely to reopen in freeze thaw cycles.

Basement sump pump system with vertical discharge pipe beside concrete block and brick foundation walls

Sump Pumps & Battery Backups

Many Markham basements rely on sump pumps to keep water under control. We install new sump pits and pumps, replace older units and can add battery backup systems so you still have protection during storm related power outages, when you need the system most.

Exposed brick foundation wall with perforated drainage pipe set in clear gravel

Drainage & Footing Drains

Poor surface drainage and overloaded footing drains are a major cause of leaks. We locate and repair existing footing drains when possible, install new weeping tile where needed and improve surface drainage with downspout extensions, splash pads and grading so water moves away from your foundation instead of pooling beside it.

Window Wells & Cold Rooms

Basement window wells, walkouts and cold rooms are frequent leak points in Markham homes. We rebuild or improve window wells with proper drains, seal and insulate cold room walls and ceilings and tie these areas into your overall waterproofing plan so they do not remain the weak spots after the rest of the work is finished.

Our Waterproofing Process For Markham Homes

Effective waterproofing is a process, not just a single product. We explain every step so you know how your home is being protected and what you are paying for.

Inspection And Leak Tracking. We examine the basement and exterior, map cracks, note staining and ask when and where water appears. This helps us separate normal condensation and humidity from accurate leaks through the foundation or slab.
Lot, Soil And Drainage Review. We look at how your lot slopes, how close you are to ravines, ponds or the Rouge River system, and where downspouts and hard surfaces send water. In Markham, clay soils and dense paving can alter the pressure a foundation experiences.
Solution Design. Based on what we find, we recommend exterior waterproofing, interior systems or a combined plan, along with any needed masonry repairs, so the structure is sound before we seal it.
Waterproofing Installation. We install membranes, drainage boards, weeping tile, interior channels, sump pumps, and crack repairs using methods that match your foundation type, whether it is poured concrete, block, stone or a mix from different construction stages.
Site Cleanup And Walkthrough. After installation, we backfill and compact the soil correctly, tidy the job site, and walk you through what we did, where the drains and pumps are located, and how to keep the system working correctly.

Waterproofing Service Areas In Markham

We provide basement and foundation waterproofing across Markham and nearby communities, including:

Unionville and historic Main Street area

Markham Village and Old Markham

Cornell and Box Grove neighbourhoods

Greensborough, Wismer and Raymerville

Milliken, Steeles East and Denison area homes

Neighbourhoods near Highway 7, 404 and 407

If your home sits just outside Markham, we likely still service it as part of our broader Greater Toronto waterproofing service. Ask our team and we will confirm.

Combine Waterproofing With Other Masonry Services

Waterproofing works best when your masonry is solid. As a full masonry contractor, we can repair and improve the exterior of your Markham home before or alongside waterproofing, so you address structural and moisture issues at the same time.

Not Sure Where The Water Is Coming From

Many homeowners only see the result, such as a damp corner, a wet patch or a musty smell. We can investigate, test and map where water is entering and recommend waterproofing or drainage solutions that make sense for your Markham home and lot.

Markham Waterproofing FAQs

Do I always need exterior waterproofing to fix a leak

Not always. Exterior waterproofing is the most complete approach when we can reach the outside of the wall, but interior drainage and sump systems can be very effective when excavation is limited by decks, additions, property lines or tight side yards. We explain the trade offs for your Markham home so you can choose with clear information.

How long will my waterproofing last

A properly installed exterior membrane, drainage system and sump setup can protect your foundation for many years. Exact lifespan depends on soil conditions, grading, water load and future changes to landscaping or hard surfaces. We design systems with durability in mind and explain how to keep them working well.

Can you waterproof older stone or block foundations in Markham

Yes. Many Markham homes, especially in Unionville and Markham Village, have older stone, block or mixed foundations. We adapt our methods and often combine masonry repairs, repointing, parging and waterproofing so structural work and water protection support each other instead of working against each other.

Is my leak just condensation or a foundation problem

Condensation usually appears on cool surfaces during humid weather and can often be improved with ventilation and dehumidifiers. A foundation leak tends to show up after rain or snow melt at the base of walls or in corners and may leave mineral deposits. During our inspection we help you tell the difference and pick the right solution.

Will waterproofing damage my yard or landscaping

Exterior waterproofing requires excavation, which disturbs soil and any landscaping in the work area. We plan access routes carefully, protect what we can and restore the area after backfilling and compaction. If you have landscaping or hardscaping plans, we can coordinate timing so disruption is kept to a minimum.

Protect Your Markham Home From Water Damage

If you see wet corners, damp walls or musty smells in your basement, the problem usually does not go away on its own. A&A Masonry can inspect your Markham home, help you understand what is happening and design a waterproofing plan that fits your home, lot and budget.