Why does my quote from a Kanata contractor list primer as its own price?

Primer is priced separately because it is a distinct product and a distinct step, and its cost depends on your slab's condition in ways the contractor cannot always know until prep is done.

A resinous floor system is built in layers, and the primer is the first one. It goes onto bare, prepared concrete before any body coat or topcoat. The primer's job, the products used, and the quantity needed can all vary from job to job, so many contractors break it out rather than bundle it into a single per-square-foot line. That is not unusual in a commercial quote; it gives you more visibility into what you are actually buying.

A few things affect what primer costs and why it appears as its own line:

• Slab moisture. One manufacturer's data sheet lists a moisture limit for its epoxy primer at below 80% relative humidity. If your slab tests above the product's limit, the contractor may need to switch to a moisture-tolerant or moisture-mitigating primer, which is a different product at a different price. Pricing it separately lets the contractor adjust that line if the moisture test result changes the product choice.
• Surface profile. Data sheets for resinous systems ask for a prepared surface profile, referenced against ICRI concrete surface profiles CSP 1 to 10. The primer's coverage rate and the number of coats can shift depending on how open or dense the concrete is after grinding.
• Coverage and waste. On a floor with cracks, low spots or a very porous slab, primer absorbs more product per square foot than on a tight, dense surface. A separate line makes that variable visible.
• Product specification. Some systems use a penetrating epoxy primer; others use a broadcast or slurry coat as a first layer. These are different products with different costs, and the data sheet for each governs how it is applied and what it is compatible with.

When you review the quote, ask the contractor to confirm which primer product is specified, what moisture threshold that product requires, and what happens to that line item if the moisture test result means they need to switch products. Ask also whether the primer price assumes a single coat or whether a second primer coat is included if the slab is more porous than expected.

Published 2025-2026 contractor ranges put commercial epoxy systems at about $8 to $15 per square foot installed, with lighter commercial systems from about $5 per square foot. Standard surface prep, when quoted separately, runs about $1 to $3 per square foot. Your quote will differ based on slab condition, system thickness, and what the prep reveals.

After the job is done, keep the written contract, the product data sheets and safety data sheets for every product applied, the WSIB clearance certificate, any written warranty, and photos of the slab before and after prep. Those records are worth holding onto if a question about the floor comes up later.