Sealing a garage floor - protecting concrete from oil and road salt

Concrete is porous and soaks up whatever lands on it. In a garage that happens from several directions at once. In winter the wheels bring in meltwater and road salt, and the salt travels into the pores with the water. Oil drips from the engine and does not stay on top: it soaks in and within a few days sits several millimetres below the surface. Every time you drive in and turn, the tyres wear away the top layer.

Then there is dusting - the grey powder that comes back every time you sweep. The cause usually lies in the slab itself: if the concrete was poorly trowelled, the material itself dusts, and a sealer will not replace a hardener. Loose particles on the surface, on the other hand, are bound by a product that forms a polymer layer. EI-19 colour sealer gives exactly this kind of dust-free layer and evens out the colour of the floor at the same time.

A sealer penetrates the concrete and reduces how much it absorbs. A penetrating product forms no film on top, so it does not change grip and the floor does not become slippery. A coating sits on the surface: it takes the wear, but needs renewing over time.

In a garage the sealer is the foundation. If the floor also has to cope with heavy traffic, add a wear layer such as Polish’Guard anti-slip wax. This acrylic coating resists abrasion and scratches while reducing slip. Used undiluted it builds a wear layer; diluted 1:9 with water it is for routine maintenance. It does not replace a sealer: the sealer works inside the material, Polish’Guard on top of it.

Cover a fresh stain with an absorbent first - sand, sawdust or cat litter - and collect whatever has not yet gone deep. For individual stains there is OL-1 CTS Chemistry oil stain remover, ready to use, at about 0.1-0.3 l/m². When the whole floor is greasy, with lubricants and tyre marks, Net’Guard Ultra 4 in 1 is more practical: apply it undiluted, give it at least 15 minutes and do not let it dry before rinsing. For workshop-type grime, EC-90 EKSIL does an excellent job. OL-1 and EC-90 are strongly alkaline, so wear gloves and safety glasses.

What to do with an old stain that has been washed many times is covered in our guide to oil stains on paving and concrete. You will find products for greasy dirt on the grease and oil page.

After washing, rinse the floor and let it dry - not just on the surface, but in the pores. Freshly poured concrete must first release its mixing water: some products require the substrate to cure for 28 days.

For a closed garage, EH-20 EKSIL, a water-based water- and oil-repellent sealer, is an excellent choice. It limits the penetration of water and oils, does not change the colour of the concrete and is vapour-permeable. Apply it undiluted in a single coat - by roller, brush, sponge or low-pressure spray - at +10 to +30 °C. A litre covers 4-12 m², and on smooth concrete you will get close to the upper figure. It needs at least a full day to dry.

If you can keep the space well ventilated during and after the work, solvent-based EH-18 EKSIL does an excellent job; it is made for concrete and floors, including those that carry traffic. It limits the penetration of water and the road salt dissolved in it. It adds no gloss and does not change the colour, at most slightly darkening and matting the surface, so test it first on light concrete. Work at +5 to +30 °C; a litre covers 4-7 m², and porous concrete takes a second coat. It is touch-dry in 2-3 hours and fully cured after a day - until then, keep use of the floor to a minimum.

How to match the base to garage conditions is explained in our guide water-based or solvent-based sealer. You will find the other products in the concrete and floors category.

Wet tyres and spilled oil can turn a smooth floor into an ice rink. Find the cause first: a greasy film comes off with degreasing, while a smooth material that is slippery in itself needs an anti-slip treatment. How to tell them apart is shown in our guide to slippery paving, terraces and tiles.

On concrete, Guard Slip Resistant works excellently. It reacts with the silica in the substrate and improves grip even when the surface is wet, without changing its appearance. One application is enough, and a litre covers 10 m². If your garage floor is ceramic or porcelain tile, go for R-9C CTS Chemistry.