Which floor repair layers actually have to be food-grade?

In a food plant, generally only the final inch or so of a floor repair has to be food-grade. The layers underneath it — compacted stone, the ordinary concrete that shapes the fall, the material that brings the level back up — end up buried and sealed under the finish, so they can be conventional materials.

What sits on top is a base coat and a top coat of food-grade polyurethane cement, with a non-slip aggregate broadcast where the room needs one. That is the part that gets touched, washed, walked on and inspected.

This matters commercially. Specifying food-grade material through the full depth of a repair that goes more than a foot down is a straightforward way to multiply the cost of the job for no benefit, and it happens often enough that it is worth putting in writing.

What makes a material food-grade in the first place?

It is a certification question more than a performance one. In an ordinary building we would repair a floor with standard concrete and cement repair materials and be done. In the production areas of a food plant, the material has to be cleared for use in a food environment, and the plant has to hold the documentation that says so.

That second half is the part contractors underrate. The plant is not only buying a floor that lasts. It is buying the ability to stand in front of an inspector and say: this is what is on our floor, here is why it is approved, here is the paperwork. A material that performs beautifully and cannot be evidenced is not usable in that room.

We deliberately do not publish the certifying bodies or approval numbers for the products we use — those belong on the current data sheet, not in an article that will still be online in three years. Ask for them at quotation and check them against the manufacturer’s live documentation.

Where does the food-grade zone actually start and stop?

By what the room is used for. Not by which corridor it opens off, and not by what it looks like.

The clearest example we have came from this exact question. At a food-processing plant in south Etobicoke there is a defined line between the office areas and the production areas, and we were asked to use a cheaper epoxy in a space on the office side — described to us as good enough for that room.

When we got there it was the micro testing lab. It looked like an office. There were people in lab coats at desks. It was where quality control testing is done.

We stopped and said this is not a room for ordinary epoxy — it needs the same approved products as the production floor. It went to the engineers, the engineers agreed immediately, and it was finished in food-grade material.

Nobody in that chain was being careless. The room genuinely looks administrative. But a cheaper epoxy in a micro lab is a finding waiting to be written up, and the contractor is the one person on site who is about to permanently change what is in that room.

Our position: if a contractor takes the cheaper scope in a plant without asking what the room is used for, they are handing the client a compliance risk the client never agreed to accept. That question costs nothing to ask.

What does the build-up look like in practice?

On a typical rebuild in a production area, working from the bottom:

1. Compacted stone where the excavation went below slab level — ordinary material, buried.
2. Ordinary concrete to bring the level back and, where needed, to build the fall towards the drain. Also buried and sealed.
3. Food-grade base coat — the first layer of the certified system.
4. Food-grade top coat, with non-slip aggregate broadcast in and encapsulated where the floor runs wet.

The buried layers still have real work to do — where the concrete beneath is shaping the fall towards a drain, it is doing the job described in why water ponds on a plant floor, and only the finish over it is certified.

The same logic applies to a localised repair as to a full room. Our write-up of localised floor repair with cementitious urethane at this plant sets out the preparation in detail — the sawcut edge, the chase width, taking the substrate down to non-carbonated concrete — and every bit of that prep sits under a food-grade finish that is a fraction of the total depth.

Where the whole floor is being renewed rather than patched, the same two-coat approach scales up: the floor coating work through the production areas at this plant is an antibacterial cementitious urethane in two layers with aggregate broadcast and encapsulated.

Does the thinking transfer outside food plants?

The certification does not always transfer, but the reasoning does. In hospitals, labs and other occupied regulated buildings, the material gets chosen by what the room is used for and what the operator has to be able to demonstrate — often before anyone looks at performance. That is the same conversation we have on medical facility floors.

For the material families themselves and where each one belongs, our floor coatings overview is the place to start, and the questions plant and property managers ask most often are collected on our FAQ page.