Oil-soaked shop floor in Gloucester, can it be coated?

Whether an oil-soaked concrete floor can be coated depends on how deeply the oil has penetrated and whether the contractor can achieve a clean, sound surface. The contractor needs to assess the slab before committing to a system or a price, and should tell you in writing how they will deal with the oil and whether the product's data sheet allows coating over the prepared surface. The prep has to reach the profile the chosen product's data sheet requires. ICRI concrete surface profiles (CSP 1 to 10) are the reference point; one resinous system data sheet asks for CSP 3 to 4, and a urethane cement data sheet asks for CSP 3 to 5. If oil remains in the pores after preparation, the data sheet for any product the contractor proposes should be checked to confirm whether that product can bond to the prepared surface. Whether the job is feasible depends on the slab, the product, and what the data sheet says.

On cost, published 2025-2026 contractor ranges for commercial epoxy run about $8 to $15 per square foot installed, with lighter systems from about $5 per square foot. Surface preparation, when quoted separately, runs about $1 to $3 per square foot, but heavily contaminated or damaged concrete costs more and we found too few published prices to give a range for that work. Your quote will differ.

Under the Occupational Health and Safety Act, s.30(1), before work begins you must determine whether any designated substances are present and prepare a list. O. Reg. 490/09 lists asbestos among designated substances. If there is old vinyl tile or black mastic under any part of the floor, have it tested before any grinding takes place.

Ask for proof of liability insurance and references on similar contaminated-slab jobs.

Before a contractor visits, pull together what you know: how long oil has been soaking in, what products were spilled and how often, what traffic the floor sees, whether any old tile or adhesive is present and needs testing, and how long the space can realistically close. Ask the contractor, once they have seen the slab, what surface profile they are targeting and which product data sheet they are working from.