The middle of a basement floor is easy. Every judgement call on the job happens at an edge: where the floor meets the wall, where it meets the stairs, and where it meets the room next door.
Those three details are the difference between a coated basement that reads as a finished room and one that reads as a painted cellar.
Cove base
A cove base carries the coating up the wall a few inches in a radius instead of stopping at a right angle.
What it buys you. No corner to trap water, dust and whatever the shop vac misses. The whole room can be washed down as one surface. And visually it finishes the floor, in the same way a baseboard finishes a wall.
Where it matters most. Laundry rooms, utility spaces, anywhere with a floor drain, and anywhere you would ever hose down. Also anywhere the wall is concrete or block, because bare block at floor level absorbs everything.
Where you can skip it. A dry storage basement where the walls are already finished and the floor is never getting wet. It is a line item, not a requirement.
Stairs
Basement stairs are usually the ugliest concrete in the house and the most awkward to coat well.
Treads get the same build as the floor with more texture, because stairs are where people fall.
Nosings are the wearing edge and they take the most abuse. A rounded or chipped nosing gets rebuilt before coating, otherwise the coating just follows the damaged shape.
Risers are optional. Coating them looks more finished; leaving them saves money.
The honest note: coated stairs are more labor per square foot than the floor by a wide margin. There is no way to run a machine on a stair, so it is all hand work. If the quote for the stairs looks disproportionate to the area, that is why.
Transitions
Where the coated floor meets something else, and there are usually three.
The doorway to another room. A coating is only about 30 to 40 mils thick, so the height change is negligible. It terminates in a clean line at the door, and it looks best terminated under the closed door position rather than in the opening.
A carpeted or floated area. If part of the basement is staying as it is, the coating stops at that boundary. A metal or wood transition strip goes over the joint.
The bulkhead or hatchway. Outside light, outside water, and a slab that is often a different pour and a different age. That junction gets treated flexibly rather than filled rigid, so the two pours can move independently without cracking the coating.
Where old and new concrete meet
Extensions, added rooms, patched sections. Two pours of different ages will move independently for the life of the building.
Filling that joint rigidly forces the crack to appear somewhere else. We treat it flexibly and carry the coating across, which is what stops it telegraphing through the finish.
Related
- What we do on basement floors
- Removing old floor paint, which usually comes first
- Moisture testing, which comes before all of it
Reference
Coved detailing and joint treatment are standard elements of resinous flooring specification, sitting on the same prepared substrate described in Guideline 310.2R by the International Concrete Repair Institute.