Concrete Finish Questions Checklist

Ask whether the proposal is a poured slab, a precast piece brought in, a thin cement-based overlay, or an existing slab ground and polished.

These involve different trades, different preparation and completely different expectations about appearance.

If a thin overlay is proposed, ask how much it adds to the floor and what it needs beneath it to stay sound.

Overlays follow the movement of whatever they are applied to, which is why the background matters so much.

What an overlay needs beneath it, and whether the existing floor is suitable, must be established by a qualified professional.

Ask who actually carries out the work, whether it is a general trade or a specialist, and who you speak to if the result is disputed.

Cement-based finishes are strongly dependent on the applicator, and responsibility is easier to establish beforehand.

Ask to see surfaces the same applicator has finished using the same method, in person rather than in photographs.

Photographs of concrete are lit selectively, and this material more than most needs to be seen in ordinary light.

Ask how much of the aggregate would be exposed if the surface is ground, and see examples of each level of exposure.

The degree of grinding changes the appearance entirely, and it is decided on site while work proceeds.

If the finish is proposed for a worktop or a vertical surface as well as a floor, ask what differs between those applications.

The same material behaves differently where it is handled, splashed or seen at close range.

Ask what the existing floor is made up of and record what you are told, since the answer shapes everything that follows.

The layers already in place decide what can be added and how the finish will behave.

Note every door that opens into the room, and ask what happens to those doors if the floor level rises.

Doors, thresholds and the bottom of skirting are the first things affected by an added floor layer.

Walk to each threshold and ask how the new finish would meet the floor in the next room without an awkward step.

Junctions between finishes are decided on site if nobody discusses them, and the result is often visible from the doorway.

Ask a qualified professional what weight the proposed finish adds and whether the floor can take it in this property.

This is a technical question with a technical answer, and it should be settled before anything is ordered.

Whether a floor can carry a concrete finish must be established by a qualified professional for the actual property.

If there is underfloor heating, or there may be, tell the applicator now and ask what that means for the finish and its joints.

Heating beneath a cement-based finish changes how it moves, and it is far better raised early.

How a finish is used over underfloor heating is a matter for the applicator, the heating installer and a qualified professional.

Ask the applicator to state plainly how closely the finished surface can be expected to resemble the sample you were shown.

Samples are made in controlled conditions and a large area laid on site rarely reproduces them exactly.

Ask the applicator to describe the expected range of variation in writing before the work is agreed.

Ask whether a sample area can be made in the actual room, in the actual light, before the whole surface is committed.

A panel made on site under real conditions is the only honest preview of what you will get.

Ask what marks the method leaves from the way it is worked, including trowel lines, laps and darker or lighter patches.

These marks are inherent to hand-applied finishes rather than defects, but only if you know that in advance.

Ask where the work would pause across a large area and whether that pause line remains visible in the finished surface.

A stopping point in a continuous pour or application can show as a line, and its position is a decision.

If the finish is coloured, ask how consistent that colour is across an area and what happens where material is mixed separately.

Coloured cement-based finishes vary between batches, which is most visible in a broad open floor.

Look at any example under light that rakes across it at a low angle, such as from a large window or a wall light.

Raking light exposes every undulation and lap mark that flat overhead light conceals.

Ask the applicator to describe in writing what cracking and crazing they consider normal for this finish in this situation.

The difference between character and a defect should be agreed before the surface exists, not argued afterwards.

Whether any particular crack matters must be judged by a qualified professional looking at the actual surface.

Ask where any joints would fall, why they fall there, and whether their position can be discussed before work begins.

Joints are placed for technical reasons but they are also visible lines across a room.

Take the layout of furniture and rugs into account when discussing joint positions, and mention any run of open floor that matters to you.

A joint through the middle of the main sightline is far more noticeable than one near a wall.

Ask what happens where the finish meets walls, columns and thresholds, and what fills those junctions.

Perimeter junctions are where movement is accommodated, and they are visible details in their own right.

Point out any existing cracks in the floor or walls and ask what a qualified professional should look at before work is planned.

Existing movement affects what any new finish will do, and it is not an owner judgement to make.

Existing cracks in a floor or wall must be assessed by a qualified professional before any finish is applied over them.

Ask what sealer is proposed, what it actually reduces and what it does not prevent at all.

Owners commonly expect a sealed concrete surface to be impervious, and it generally is not.

Ask to see the same sample sealed and unsealed side by side, since sealers often deepen the colour noticeably.

Sealing is a design decision as much as a protective one, and it is usually shown only after the fact.

List what genuinely gets spilled in this room, such as cooking oil, wine, pet accidents, plant water or workshop products, and ask about each.

A specific list gets a specific answer, whereas a general question about staining invites reassurance.

Ask how you would recognise that the sealer needs reapplying, who does that work and what it involves for the room.

Reapplication that requires clearing the whole room is a different commitment from a simple wipe over.

Ask which cleaning products are compatible with the sealer, and which would strip it without any obvious sign.

Protection can be removed quietly by an ordinary product long before any staining appears.

Ask what sheen the sealed surface will have and look at an example, since a shiny concrete floor reads very differently from a matt one.

Sheen level is chosen with the sealer, and it changes the character of the material completely.

Stand on a comparable surface for a while and consider how it feels for the people who will be on their feet in this room.

A hard floor in a kitchen or a workroom is a daily experience rather than an occasional one.

Listen to how sound behaves in a room with a similar hard floor, and consider what soft materials the room would still contain.

Hard floors raise the sound level noticeably, particularly in rooms with hard walls and little furniture.

Ask what happens both to the surface and to the thing dropped, particularly in a kitchen where glass and crockery fall.

The surface may survive a dropped item better than the item survives the surface.

Ask how the surface feels underfoot in cold weather, and whether the room has any heat source that reaches the floor.

Cold underfoot is a common regret and is much easier to plan for than to correct.

Ask the applicator how the finish behaves when it is wet, and raise that with a qualified professional for any area near a door or a shower.

The way a floor behaves when wet is a technical matter, and describing the position accurately is what helps.

Anything to do with a wet floor surface belongs with the applicator and a qualified professional, judged on the specification actually being used.

Ask where this work falls in the sequence, what must be finished beforehand and what has to stay out of the room afterwards.

Sequencing is the single biggest cause of damage to a new concrete finish.

Agree who provides protection over the surface once it is formed, and who is responsible if it is damaged before completion.

Protection is often assumed by everyone and provided by nobody.

Agree in writing with the applicator and contractor who protects the surface and who bears responsibility for damage.

Ask what has to happen before anything is placed on the surface, and how you would know that stage has been reached.

Covering a cement-based finish too early can mark it permanently, and the marks appear later.

Ask how materials reach the room, whether machinery is involved and what noise, dust or disruption that brings to the house.

Grinding and mixing are noisy and dusty, and knowing that in advance changes how you plan the household around it.

Ask whether the property can be occupied while the work and any sealing take place, and what the applicator advises about ventilation.

Applied products have their own requirements, and this is a question for the applicator and the product information.

Ask what would be involved if something buried had to be reached later, and whether the position of services beneath is recorded.

A continuous floor over services means any later access involves breaking the finished surface.

Ask honestly how visible a patch repair would be in this finish, and whether anyone would attempt one rather than redoing an area.

Patch repairs in cement-based finishes rarely disappear, which shapes how you treat the surface.

Ask what happens if something needs to be fixed into the surface later, such as a screen, a rail or a piece of furniture.

Fixings into a finished concrete surface are not always straightforward, and the question is better asked early.

Record what was actually used, including any colour reference, the sealer and the applicator details, and keep it with the house papers.

That record is what makes a sensible conversation possible if the surface ever needs attention.

Ask for the product information for the sealer and any repair material used, and keep a note of who supplied them.

Sealers are almost impossible to identify by appearance, so the product information is what any later reapplication depends on.