Interlock contractor in Ottawa: patios, walkways and driveways.

Most of it happens below the surface you will see. We draw the layout in 3D and AutoCAD, excavate, and set the grade so water runs away from the house. Then comes the base: gravel compacted in thin lifts, and Techo-Bloc's own FAQ recommends 6 to 8 inches of it under a patio, with more under a driveway because it carries a vehicle. A screeded bed of bedding sand goes on top, then the Techo-Bloc or Permacon pavers, then polymeric sand swept into the joints. That sand is water-activated, so it needs dry, above-freezing days, and Hanover's installation guidelines keep foot traffic off it for 24 hours and cars for at least 48. In Ottawa, that is what closes the season in late fall, well before the ground itself freezes.

We do not publish a square-foot price for interlock. An Ottawa quote turns on things we measure on site: how deep the dig goes and what is underneath it, how much base the use needs, the stone and finish you choose, the cuts a pattern needs, the edge restraint, and whether a machine can reach the work. A driveway adds the width the City allows on your lot and, for a new or wider access, the City's access permit, $208 in 2026. We found no Ottawa-only installed figure with a named source. The nearest named benchmark is a Canada-wide contractor survey Techo-Bloc published in July 2026, which our Permacon and Techo-Bloc guide sets out with its limits. You get one price, against a 3D design you have already approved.

The City regulates two parts of an interlock job directly. A driveway meets the street in the City's right of way, so building, widening, closing or removing a vehicular access needs an access permit under the Access By-law (No. 2026-139). The 2026 fee is $208, processing takes about six to eight weeks, and relaying the same footprint does not need one. The City also caps the total width of all accesses at 50 per cent of the lot frontage. The second is height: under the City's Building Code Services advisory, a retaining wall, stair or landing more than 1 metre high needs a Part 4 engineering design, and a building permit and a guard follow where the structure provides access to the house and meets one of the advisory's height or slope tests. We check both against your plan before we quote.

Ask how deep the base will be and how many lifts it is compacted in, because the base is what keeps the surface level through freeze-thaw. Ask where the water goes: the City of Ottawa's lot grading guidance says to extend a downspout at least four feet from the foundation onto a permeable surface such as grass, and a downspout that empties onto the stone is how the same corner keeps sinking. Find out which exact Techo-Bloc or Permacon product is going down and read its warranty, because the two differ: Techo-Bloc's residential warranty is for life and covers surface damage from de-icing salt, while Permacon's runs 50 years, prorated, and excludes surface damage from misused salt. Neither pays for labour, so ask for the workmanship warranty in writing too.

A properly built base is what keeps interlock stable through our freeze-thaw cycles, and that is where we focus most of the work that never shows once the project is finished. We excavate to the right depth and build the base up in compacted lifts so water drains and the ground moves evenly instead of pushing unevenly on the surface above it. When the foundation is done right, your patio, walkway or driveway stays flat and true season after season, and if a paver ever does settle, it can be lifted, the base corrected, and the same stone reset rather than replacing the whole surface.

We dig out the area, then build the base up in thin compacted lifts rather than one loose layer, which is what gives the surface its strength and its resistance to freeze-thaw movement. On top of that we screed a level bed of bedding sand and set each Techo-Bloc or Permacon unit into it, then lock the joints with polymeric sand once the pattern is laid. A driveway gets a thicker base than a patio because it has to carry vehicle load, and the slope is designed in from the start so meltwater runs away from the house instead of pooling at the door. This layered approach is built for Ottawa soil and the freeze-thaw movement that comes with our winters.

Polymeric sand is a jointing sand that hardens once it is swept into the gaps and wetted, locking the pavers together so they move as one surface instead of shifting individually. Because it sets firm, it helps keep the joints stable and discourages weeds and ants far better than plain sand, which washes out and leaves an open gap over time. A stray seed can still land on the surface and take root, but occasional sweeping and topping up the polymeric sand every so often keeps the joints looking clean and locked. It is a small, low-cost part of the build that does a lot of the long-term work.

Sealing is optional. It can deepen the colour, add a slight sheen and make cleaning easier, but a well-built patio or walkway holds up fine without it, since the durability comes from the base and the pavers, not the sealer. Day-to-day maintenance is light: sweep it, rinse it, and top up the polymeric sand from time to time as it wears. If a paver ever settles or is damaged, individual units can be lifted and reset rather than replacing the whole surface, which is one of the biggest practical advantages interlock has over a poured concrete slab or asphalt.

Interlock flexes with our freeze-thaw ground instead of cracking like a poured slab, because it is made of many individual pavers on a compacted base rather than one rigid piece, and single units can be lifted and reset if one ever settles. Poured concrete and asphalt usually cost less up front, which is a fair reason people choose them, but the trade-off is that a crack cannot be un-cracked, and a patch tends to show and keep moving. Over the full life of the surface, interlock is generally the higher up-front investment that is built to be repaired in place rather than torn out and redone. We walk through the full trade-offs in our interlock-versus-concrete guide so you can weigh both honestly for your yard.

Yes. We build retaining walls and steps with Techo-Bloc and Permacon block, set on a compacted base with proper drainage behind the face so the wall holds back soil and handles our winters without bulging or shifting. Quality interlock and stonework is a long-term investment that holds up well for years when the base is built correctly, and because it is modular, a settled or damaged unit can be reset rather than replacing the whole wall or surface. Every project comes with a written workmanship warranty, with the exact terms set out in your signed project agreement, and we design retaining walls in 3D and AutoCAD first so you approve the exact height, layout and finish before we dig.

Yes. When a paver settles or lifts, we take up the affected stones, correct and re-compact the base underneath, and reset the same pavers, so the repair does not leave a visible patch. The same base-first approach handles a settled section of patio, walkway or driveway apron, and where the joints have washed out we re-sand them with polymeric sand to lock the surface back together. Because interlock is modular, we work on the affected area rather than tearing out and replacing the whole surface, which is one of the biggest practical advantages it has over a poured concrete slab that cannot be un-cracked.

When the base is built correctly, interlock is a long-term investment that holds up well for years. We excavate to the right depth and build the base up in compacted lifts so water drains and the ground moves evenly, which keeps a patio, walkway or driveway flat and true season after season through our freeze-thaw cycles. And because it is modular, if a unit ever does settle it can be lifted and reset rather than replacing the whole surface, so it can be kept in good shape over a long Ottawa timeline.