Floor Preparation Advice

How do I remove oil from a painted floor?

It is important to use a degreaser which is powerful enough to break down and remove grease and oil, but gentle enough that it won’t damage the existing paint.

Watco Bio D is a solvent-free, biodegradable emulsifying detergent which is ideal for use on previously painted floors. Although it’s solvent free, it’s as effective as a traditional solvent-based cleaner. It will not ‘bleach’ the existing paint or soften it, whereas solvent-based ones will. It can also be used in confined spaces and is odorless.

Its emulsifying action means it will break down light to medium contamination of oil and grease and ‘lift’ it out of the floor.

Application is simple - just brush in the undiluted Watco Bio D with a stiff broom and leave for roughly 5-10 minutes so that it can penetrate, then scrub it with a stiff broom or mechanical scrubber and rinse away with clean water.

Tip – Watco Bio D is also really effective on dirty and oily machinery and it brings it back to life, looking like new.

How do I prepare a non-porous floor for painting?

Watco Powerfloat Base Coat is specially formulated to allow smooth or painted surfaces to be painted or repainted successfully.

Most floor paints rely on being able to penetrate (or “wet-out”) into the concrete. They can flake or peel if they just sit on the surface. Sometimes concrete is trowelled to such a smooth, dense surface that it is not porous, so the paint could fail because it cannot be absorbed. The traditional way of “opening up” such hard, smooth or “power floated” surfaces are by abrading it or perhaps shot blasting, but this can often be time-consuming, messy/dusty and expensive.

Application of Watco Powerfloat Base Coat is straight forward; just stir the tins of resin and curing agent, then tip each small tin into the tall outer tin and mix together using our paint mixer or a wide bladed tool such a wooden batten. Mix it for 2–3 minutes until it is streak free and looks even in color. Then, just tip it all into a shallow tray and apply it using a medium pile roller (we can supply all the tools you need for the job!). Use a paintbrush for cutting in around the edges.

The primed surface can be painted with one of Watco’s range of solvent-free or water-based coatings after 16 hours, or only 3 hours if the rapid version is used. Allow five days for solvent-based coatings such as Concrete Floor Paint.

TIP – To see if you need Watco Powerfloat Base Coat, pour a cupful of water onto your hard, smooth or power-floated concrete. If the water soaks in, it is fine to be painted. If the water beads up on the surface and doesn’t disappear, it shows that the concrete will not absorb the paint and Watco Powerfloat Base Coat would be strongly recommended.

How do I prepare the porous floor before painting?

Most uncoated concrete floors are porous and if you put a coating directly on the screed without preparing it, the paint will just seem to disappear! This is easy to overcome by applying a coat of 4 Hour Epoxy Primer.

It’s a two pack, a solvent-free primer designed to reduce the porosity and help strengthen the screed and bind it together prior to coating it. This is important – porous screeds such as sand and cement lack the strength of concrete and as the surface weakens, it can lead to premature wear of a new paint coating. Another added benefit is that you only need one coat so you can prime and overcoat in just one day and get the area back into use quickly.

It’s easy to use - just mix the two liquid components together and tip into a plastic tray. Apply it with a roller (not a foam one). You can use a paintbrush for cutting in around the edges. Assuming the floor temperature is around 50-59˚F and the room is well ventilated, you can overcoat it within 2-4 hours; basically, if it’s dry to the touch, it’s ready to be painted.

How do I paint a damp concrete floor?

If you have rising damp or general damp problem, this has to be sealed in before you can paint it. Liquid Waterproofer is ideal for this. In fact, the floor must be damp or wetted first in order for this to work.

Liquid Waterproofer acts as a damp proof membrane and will hold back damp and rising damp and provides a waterproof coating. It not only holds water back but can also be used to ‘contain’ it making it perfect for water storage areas and ponds (it won’t harm fish).

Another benefit is that it’s thick and flexible, so it will cope with some movement and will fill minor cracks too.

To apply it, just mix the Liquid Waterproofer powder with the liquid. Make sure the floor is damp before applying the first coat, (this is important or the Liquid Waterproofer will not sink in), and apply the first coat with a short-bristled brush. A medium pile roller leaves a textured finish. If you want it smooth, either use a squeegee to apply the product or finish with a smooth short pile roller. The second coat can be applied as long as the first coat has dried (usually after 12-24 hours depending on temperature). The total thickness after the two coats have been applied should be somewhere in the region of 1-3mm.

You can either leave it as it is or if you would prefer to paint it, leave it for 24-48 hours (depending on drying conditions and temperature) then use any of our water-based epoxy coats.

TIP – If mixed thickly it can even be used to waterproof walls.

TIP – Clean all the tools immediately after use with water.