My parents are getting interlock quotes for their Brampton driveway and I’m helping them evaluate. The spread is confusing — hoping the community can help us understand what we’re seeing.
The driveway: Approximately 480 sq ft, standard single-car width extending into double at the top. Gentle slope toward the street. Existing asphalt being removed.
Quote 1: $14,200 for Holland Stone (grey/charcoal), includes removal and disposal of asphalt, gravel base, edging restraints, polymeric sand.
Quote 2: $9,800 — similar scope on paper but contractor was vague about base depth (“standard base”). No mention of polymeric sand.
Quote 3: $17,400 for Brussels Stone premium pattern with decorative border. Same scope as Quote 1 but nicer stone.
My concerns about Quote 2: The price difference between 1 and 2 is significant enough that something is different. When we asked about base depth, the contractor said “6 inches” but couldn’t specify between Granular A and crusher run. When we asked about polymeric sand, he said “we use regular sand.”
Is Quote 2 the classic underprepared-base quote that looks good for 3 years then starts heaving? The polymeric sand omission alone concerns me. Am I reading this right?
Would appreciate any Brampton-area interlock experience — particularly whether Quote 1 at $14,200 is reasonable for that scope.
You’re reading this right. Quote 2 is the classic underprepared-base scenario.
A few things stand out immediately:
“Standard base” is not a spec. It is a non-answer. In Brampton, a proper residential driveway base runs 10 to 12 inches of compacted Granular A stone, laid in 2-3 inch lifts with a plate compactor after each pass. If a contractor cannot tell you the base depth in inches and the material by name, they are not prepared to do the job properly.
No polymeric sand is a serious red flag. Regular sand washes out within a season or two. Polymeric sand locks the joints, resists ants, and keeps the field stable. On a driveway — where you have vehicle loads — this is not optional.
The math: Quote 2 at $9,800 for 480 sq ft is about $20 per square foot installed. Quality interlock work in the GTA right now runs $25 to $45 per square foot for a standard residential driveway. The gap between Quote 1 and Quote 2 is almost entirely base prep and joint material. That difference will show up as heaving and joint failure within 3 to 5 years.
Quote 1 at $14,200 ($29.58/sq ft) is a reasonable number for the scope described, assuming they actually deliver the base depth they are promising. Get that in writing — specifically the depth and material for the granular base, compaction method, and the polymeric sand brand.
Quote 3 is reasonable for Brussels premium with a decorative border.
Before signing anything, read the thread on the 12-inch rule — covers exactly what to ask any hardscape contractor before you commit.