When buyers tour a house in Ajax, Markham or Milton, they look at the kitchen, the bedrooms and the basement finish. Very few walk around the outside and look at which way the ground slopes. Yet grading and drainage decide where rain and snowmelt go, and water that heads toward the foundation is behind a large share of the basement leaks, damp smells and cracked walkways I see on inspections. This checklist walks you through what a home inspector checks outside and inside, step by step, so you know what to look for before you firm up an offer. Your inspector is Yama Nehan, a Certified and Registered Home Inspector with about 15 years of home inspection experience and a construction engineering degree from George Brown (Building Renovations). He is also a licensed contractor with about 20 years of construction experience and the owner of Nehan Construction, and that practical construction experience is one of the main reasons clients pick him. Yama Nehan is the only one trusted to do the inspections himself. Home inspections start from $499; the final price depends on the property. Call 647-704-7100 or book an inspection online.

Key takeaways

  • The ground next to the house should slope away from the foundation so water drains away from the walls, not toward them.
  • Downspouts that empty right beside the foundation, or into a buried pipe nobody can trace, are one of the most common findings on GTA homes.
  • Settled soil, sunken walkways, low window wells and patios that tilt toward the house are all signs to look at the basement more closely.
  • Inside, efflorescence (white powder), staining, a musty smell and fresh paint low on basement walls can point back to an outside drainage problem.
  • A home inspection is visual and non-invasive. I don’t dig, scope buried drains or move furniture and stored items, and the report notes anything I couldn’t see.
  • Inspection-first: Golden Home Inspections reports on condition and does not use the inspection to sell repairs.

Why grading and drainage matter in Ajax, Markham and Milton

All three cities have a lot of subdivisions built from the 1980s to today, often on clay-heavy soil that holds water. In newer areas of Milton and Markham, the backfilled soil around the foundation can keep settling for several years after the house is built, and the slope that was right on closing day can flatten out or even reverse. In established parts of Ajax and Markham, decades of landscaping, added patios, raised garden beds and interlock driveways often change how water moves around the house. Whatever the age, the question is the same: when it rains hard or the snow melts in March, where does the water go? For more on what a full inspection covers in these areas, see home inspection in Markham and our home inspection service.

Step-by-step: how I check grading and drainage

Step 1: Walk the full perimeter

I start outside and walk all the way around the house, including the side yards that buyers usually skip because they are narrow or full of bins. Side yards between houses in subdivisions are where I most often find flat or reversed grading, because two neighbouring lots drain into the same narrow strip.

Step 2: Check the slope next to the foundation

The ground should fall away from the house. Ontario’s Building Code expects the finished grade to direct surface water away from the building, and a commonly used guideline is a noticeable drop over the first couple of metres from the wall. I look for low spots right against the foundation, soil or mulch piled up against the siding or brick, and areas where water has clearly pooled, such as bare patches, silt lines or moss.

Step 3: Follow every downspout

Each downspout should have an extension or splash pad that carries water well away from the foundation and toward a spot where it can drain safely, not onto a neighbour’s lot or back toward a walkout. I note downspouts that are disconnected, crushed, pointing at the wall or running into a buried pipe. Buried downspout pipes can be fine, but if I can’t see where they come out, I can’t confirm they are clear, and the report says so.

Step 4: Look at the eavestroughs

Overflowing or sagging eavestroughs dump water exactly where you don’t want it. I look for dirt lines and staining on the soffit and fascia, sections pulling away from the house, and splash marks or worn soil under the roof edge, which tell me the troughs overflow in heavy rain.

Step 5: Check hard surfaces against the house

Walkways, patios, driveways and porch slabs that have settled toward the house act like a funnel. I look for tilted interlock, gaps where a slab meets the foundation, and cracked concrete steps. Walkouts and below-grade entrances get extra attention because the drain at the bottom has to stay clear or water ends up at the door.

Step 6: Check window wells and basement windows

Window wells should sit above the surrounding grade, have a drain or gravel base, and be free of leaves and debris. A window well that fills with water every storm is a common way water gets into a finished basement in all three cities.

Step 7: Go inside and check the basement walls

Then I go down to the basement and look at the same walls from the inside: efflorescence, water staining, rust on the bottom of steel posts or the furnace, damp or stained drywall at floor level, a musty smell and moisture readings where the walls are accessible. Fresh paint or new baseboards low on one wall are worth asking the seller about. If the sump pump is accessible, I note whether there is one, whether it has a cover, and whether it discharges outside away from the house. For more on what cracks and moisture can mean, read foundation cracks and basement moisture.

Grading and drainage checklist for buyers

What to check Good sign Warning sign Usual next step
Soil next to the foundation Slopes away on all sides Flat, low spots or sloping toward the house Regrade with clean fill and confirm the slope after it settles
Downspouts Extensions carry water well away from the wall Missing extensions, crushed pipes, untraceable buried pipes Add or extend extensions; have buried lines checked if leaks show up
Eavestroughs Clean, sloped to the downspouts, firmly attached Overflow staining, sagging, gaps at the seams Clean and adjust, or repair damaged sections
Walkways, patios and driveway Slope away and meet the house cleanly Tilt toward the house, gaps at the wall Re-level or seal the joint at the foundation
Window wells Above grade, drained, clear of debris Below grade, full of leaves or standing water Clear, raise or add a cover
Basement walls inside Dry, no staining or smell Efflorescence, stains, musty smell, fresh paint low on the wall Ask the seller about past water; get a qualified contractor’s opinion if signs are active

Quick checklist for your showing

  • Walk around the whole house, including both side yards.
  • Look for soil, mulch or garden beds piled against the walls.
  • Check that every downspout has an extension pointing away from the house.
  • Look for staining under the eavestroughs and on the soffits.
  • Check whether the walkway, patio or driveway tilts toward the house.
  • Look into the window wells for debris or water.
  • In the basement, smell for mustiness and look low on the walls and in the corners.
  • Ask the seller whether the basement has ever had water and whether any work was done on it.

A situation we often see

A buyer is looking at a two-storey home in a 15- to 20-year-old subdivision. The basement is finished and freshly painted, and it smells fine. Outside, though, the side yard is flat, two downspouts empty onto the narrow strip between the houses, and the interlock walkway at the side door has sunk toward the wall. In the basement, the baseboard on that same wall has a faint water line behind the furnace room door. None of it is dramatic on its own, but together it tells a story. The report explains how the water is likely getting to the wall, which items are simple maintenance and which need a closer look, and what to ask the seller. The buyer goes into negotiations with clear information instead of a guess.

What a home inspection covers, and what it doesn’t

A home inspection is a visual, non-invasive look at the accessible parts of the house. For grading and drainage that means the lot slope next to the house, eavestroughs and downspouts as seen from the ground or roof edge, hard surfaces, window wells, the visible foundation and the basement from the inside. I don’t dig, run a camera through buried drains or the weeping tile, or open finished walls. Snow cover in winter can hide the grading, and the report notes it if it does; see what a home inspector can check in winter. If long-term dampness has led to suspected mould, testing can be arranged through home hazard testing in Toronto and the GTA. You get the report within 24 hours, with photos and plain-language notes.

Choose your inspector carefully. Ask about their certifications, how many years they have been inspecting, and to see a sample report.

Frequently asked questions

Does a home inspection check the grading around the house?

Yes. I check the slope of the soil and hard surfaces next to the foundation, the eavestroughs and downspouts, window wells and the basement walls for signs of water. It’s a visual check, not a land survey.

Is negative grading a deal-breaker?

Usually not. In many cases it’s fixed with clean fill, re-sloping and longer downspout extensions. It matters more when there are also active signs of water inside the basement, so the two are always looked at together.

Can grading problems show up on a newer home in Milton or Markham?

Yes. Backfilled soil around a new foundation often settles in the first few years, and the slope can flatten out. It’s worth checking on newer homes as well as older ones.

Can you tell if the weeping tile is working?

Not directly. Weeping tile is buried and I don’t scope it. I look for signs that water is getting into the basement and recommend a drain camera inspection by a qualified contractor if the signs point that way.

How much does a home inspection cost in Ajax, Markham or Milton?

Home inspections start from $499, and the final price depends on the size, age and type of property. Call 647-704-7100 for a quote.

Book your home inspection

Buying in Ajax, Markham, Milton or anywhere in the west, north or east GTA? Yama Nehan will check the grading, drainage and basement as part of a full home inspection, explain what he finds in plain language, and send a clear report within 24 hours. Book your inspection online, call 647-704-7100, or email contact@goldenhomeinspections.ca. Golden Home Inspections is based in Toronto, Ontario.