Preparing a garage for a resin floor: what you can do yourself and what needs a professional

What you can do yourself before we arrive

This work needs no specialist equipment and shortens the crew's time.

• Empty the garage completely, including shelving bolted to the floor.
• Remove loose dirt, mortar residue and old tape from the concrete.
• Degrease fresh oil stains with a concrete degreaser.
• Provide access to power of adequate capacity and to water.
• If possible, heat the garage for a few days before and during the work.

Laitance and why it has to go

A thin, weak layer called laitance forms on the surface of poured concrete. It is smooth, dusty and has low strength. If resin is laid on laitance, it will hold exactly as strongly as that weak layer, which is to say weakly. That is why the concrete must be opened mechanically, by diamond grinding or shot blasting. This stage needs professional equipment with dust extraction.

Concrete moisture: a rough test you can do

Resin needs dry, mature concrete. A fresh slab needs several weeks, usually at least 28 days is assumed, often more. You can check moisture roughly with a simple test: tape a piece of plastic sheet tightly to the floor and leave it for a day. If condensation or a darker patch appears under the sheet, the concrete is damp.

This is only an indication, not a measurement. Before laying resin we measure moisture with an instrument and compare it with the system data sheet.

Cracks, defects and movement joints

Small defects and hairline cracks are repaired with mortars designed for resins. Movement joints are treated differently. These deliberately cut gaps let the slab move and must not be filled rigidly with resin, or a crack will appear right next to them. Joints are carried through the floor and filled flexibly. If the garage has cracks that are widening, their cause must be found first.

Old oil stains

Fresh stains can often be removed with degreaser. Old, deeply penetrated stains are harder, because oil has soaked several millimetres into the concrete. In such places it is sometimes necessary to remove more material or use a special primer. Show us these spots at the survey and we will assess how to treat them.

Air temperature and humidity on the day

Resins are sensitive to conditions. Low temperatures slow curing, and moisture condensing on cold concrete can leave dull patches and marks on the surface. The system data sheet gives the minimum substrate and air temperature and the margin above the dew point. That is why in winter the garage often needs heating, and we plan the work with the forecast in mind.

When to book the crew for a new house

In a new house the garage floor is often the last item on the list, but it is worth planning earlier. The concrete must mature and dry, and in the meantime the garage often serves as a store for building materials that leave stains and scratches. It is best to book a survey when the concrete is a few weeks old, and to schedule the work after dusty jobs are finished and before shelving and the car move in.

If the garage will be heated, it helps if the heating is already running during the work. That makes it easier to keep the temperature from the data sheet and shortens curing.

Checklist for doing the preparation yourself

If you want to do part of the work yourself, tick off these points before we arrive.

• The garage is empty, and shelving and floor hooks are removed.
• Fresh oil stains have been degreased and rinsed.
• The rough plastic sheet test showed no condensation, or you have told us the result.
• There is access to power, water and ventilation.
• The temperature in the garage has been stable for a few days.
• You know where the car will park for a few days.