Best Material for a Retaining Wall
Armour stone is the most popular retaining wall material in Ontario for a reason: it's durable, needs no mortar, drains naturally between stones, and gets better-looking with age. It typically runs more per square foot than interlocking block but needs far less long-term maintenance and rarely requires repointing or repair.
Interlocking concrete block is the budget-friendlier option and works well for shorter walls (under about 3 feet), with a more uniform, manufactured look. Poured concrete is the strongest option for very tall or engineered walls but costs the most and needs formwork and cure time.
For most residential walls under 4 feet, armour stone offers the best balance of cost, durability, and appearance. Taller walls may need engineering regardless of material choice — check your local building code before finalizing height.
Get a direct quote from Natural Stone Source Ontario on the armour stone for your wall project.
How Retaining Wall Material Pricing Compares
Among natural stone options, most approved armour stone runs $80 to $102 per ton, with specialty selections up to $325. Sawn wallstone in fixed dimensions is $406.88 to $500 per ton. Natural step material, sometimes used for low garden walls and seat courses, runs $170 to $258.63 per ton.
Interlocking concrete block and poured concrete are priced separately by their own suppliers and are not stocked here, so compare those on delivered cost for your own site.
Choosing the Right Material
Armour stone is the most common choice for Ontario residential walls. It needs no mortar, drains naturally between stones, and weathers well. Sawn wallstone costs more per ton but stacks to uniform courses where a formal look is wanted. Interlocking block suits shorter walls under about three feet and gives a manufactured, repeating appearance. Poured concrete is the strongest option for tall or engineered walls but carries the highest cost and needs formwork and cure time.
For most residential walls under four feet, armour stone offers the best balance of cost, durability and appearance. Above four feet, material choice matters less than proper engineering, drainage and base preparation.
Frequently Asked Questions
What is the best material for a retaining wall in Ontario?
For most residential walls under four feet, armour stone is the common choice: no mortar, natural drainage between stones, and it weathers well. Above that height the engineering and drainage matter more than the material itself.
How much does armour stone cost compared to sawn wallstone?
Most approved armour stone is $80 to $102 per ton. Sawn wallstone, cut to uniform dimensions, is $406.88 to $500 per ton. Armour stone gives a natural look at lower cost, sawn wallstone buys consistency and tighter courses.
Does a stone wall need drainage behind it?
Yes. Armour stone drains between the joints, which helps, but any wall retaining soil should still have clear stone and geotextile behind it so water does not build pressure. Drainage failure is the most common cause of wall movement.
How high can I build without engineering?
As a general rule, walls up to about four feet can be built without engineered drawings, provided nothing significant is retained above them. Beyond that, or where a driveway, structure or slope sits above the wall, get it engineered and check local requirements.