Sod, overseeding and lawn repair

Most sod in Kanata is laid twice. Once by the builder, over whatever thin layer of topsoil was spread on the construction subgrade, and again five to fifteen years later by a homeowner who has accepted the lawn will not recover. The second time is the one worth doing properly.

Step one: find out what is under the grass. Dig a test hole 300 mm deep in three places. You want 100 to 150 mm of dark topsoil over a subsoil that water can leave. On a Kanata builder lot you often find 40 mm of screened soil over compacted clay or crushed stone left from the driveway build. Sod laid on that greens up for one season on its own root mat and then fails. Where the soil is thin, buy topsoil before turf.

Step two: fix the water before the turf. This is the part that gets skipped and the part the City is explicit about. Ottawa's landscaping guide states that you are not allowed to change the grading of a property, and that water cannot be directed to neighbouring properties unless that is part of the approved plan (City of Ottawa). It also says not to alter ditches. So the work is restoring the designed grade, extending downspouts past the new turf, and re-cutting the swale rather than filling it in because it is awkward to mow.

Step three: call before anything goes in the ground. A locate request through Ontario One Call is free and it is the law, must go in at least five business days ahead, and comes back as instructions from each buried infrastructure owner, one of which may be to hand dig within a metre of the markings (Ontario One Call). Rototilling counts as digging, and so does a fence post.

Step four: strip, amend and grade. Old turf comes off with a sod cutter rather than being buried, because buried sod decomposes into soft hollows. Then topsoil to bring the depth up, rototilled into the subsoil rather than layered on it, so roots are not stopped at a hard interface. Grade is set to fall away from the house toward the designed outlet, rolled lightly and raked fine.

Step five: lay, roll and water. Sod goes down in staggered courses with tight joints, cut around beds with a knife rather than stretched, rolled to press the roots into the soil, then watered heavily. The first two weeks decide the outcome. Twenty minutes a day of light sprinkling wets the sod mat and never the soil beneath, so roots have no reason to go down. Soak until the soil under the sod is wet, let it dry slightly, repeat.

Overseeding, the cheaper path. A lawn that is thin rather than dead does not need sod. Core aerate, spread 5 to 10 mm of compost or screened topsoil, broadcast seed and keep it damp. Early September is the best window here, late April a distant second. It costs a fraction of sod and on compacted clay often outperforms it, because it improves the soil instead of covering it.

Timing and duration. A full front and back re-sod on a standard Kanata lot is two to four days including soil work. Best laid in May, early June, or from late August to mid October. The second half of July is how a great deal of sod dies.

What it costs in Ottawa in 2026. Indicative ranges only. Supply and install of sod usually runs $2.50 to $6.00 per square metre, the low end for large open areas and the high end for small hand-barrowed work. Screened topsoil delivered and spread is commonly $55 to $95 per cubic metre, and removing old turf adds $1.50 to $3.00 per square metre. Aeration with overseeding and top-dressing lands at $400 to $1,200 on a suburban lot. A full front and back replacement with soil sits between $3,000 and $9,000. Access sets the price more than area does.

Why Kanata lots argue with each other. Within a few streets you can have a Kanata Lakes lot with bedrock 300 mm down, where drought and shallow root depth are the problem, and a lot near the Hazeldean corridor on sensitive marine clay that swells wet and shrinks dry (NRC). On the first, soil depth is everything. On the second, drainage and aeration matter more, and imported soil laid over undisturbed clay creates a bathtub.

Licences and who should do it. No licence exists for laying sod and no certification is required. Check insurance and a WSIB clearance number instead (WSIB). A retaining wall over 1 m next to public property, next to access to a building, or on private property open to the public needs a building permit, and changing the driveway surface where it crosses the City road allowance needs a private approach permit under By-law 2003-447 (City of Ottawa). The front yard must stay at least half soft landscaping.

What to ask before you hire. How deep is the topsoil and is it screened. Will you rototill it into the subsoil or lay it on top. Where is the water going after this. Are you cutting out the old sod or tilling it in. Who is calling the locate. What is the watering instruction and is there a warranty if I follow it. Ask for the soil depth as a number, because that figure separates a lawn that lasts from one that looks good in June.