James examines what’s involved when undertaking the painting of flooring in warehouses, workshops, schools, hospital kitchens, underground car parks, or even aircraft hangars or helipads.

WHETHER you’re painting flooring in a domestic setting, a warehouse, a workshop, a school or hospital kitchen, an underground car park, or something a little more challenging like an aircraft hangar or helipad, site preparation and product selection are the keys to success.

It’s important to remember not all floor paints are the same. Generic products include alkyds, polyurethanes, epoxies, single pack, twin pack, water-based, solvent-free, moisture cure, chlorinated rubber, and more. They may be described as domestic, industrial, garage, hardwearing, tough, and flexible. Here I’ll provide advice for selecting the correct product for the job.
For domestic use, you may require a quick drying, low-odour product that’s easy to apply such as a single pack, cross linking water-based paint. For a light industrial situation, the coating should be hardwearing, grease-resistant and able to cope with light to medium traffic. A single pack polyurethane, or a water-based cross-linking product may work well.

For heavier traffic areas, such as a workshop floor where oil and grease are present, you could try a moisture cure, chlorinated rubber, or twin pack epoxy. To achieve quick-drying and recoat times, try a water-based cross linking moisture cure or chlorinated rubber.

In a work environment, such as an area for food preparation, you should use an odour and solvent-free product. Consider water-based cross linking or twin pack water-based epoxies.

There are certain circumstances where the coating must resist specific chemicals. In these cases, identify the chemicals and check the coating suitability directly with the product manufacturer.

In settings where regular deep cleaning is required such as a brewery or kennels, consider chlorinated rubber or twin-pack epoxies.

Substrates
Whether it’s concrete, steel, timber, or something else, the substrate on which the coating is to be applied is critical. When choosing a coating, consider whether the substrate is new or aged, inside, or outside, or previously covered with a different coating.

New concrete should be left for a minimum of 30 days before painting to allow time for it to completely dry out. This can be checked by laying a rubber mat on the floor and leaving it overnight. When removed, if the floor is discoloured or condensation is still visible, then moisture is still present, and the floor should be left until fully cured.

New concrete should also be checked for laitance, a milky deposit on the surface usually caused by excess water in the mix. If painted, it could act as a crust and detach from the base causing premature failure of any coating. This can be removed by blasting or acid etching.

Power floated, shiny, or unpainted nonporous concrete flooring should be thoroughly blast cleaned, ground, acid etched, or primed using an adhesion promoting floor primer before applying floor paint. The correct application of screeds is important so check with the manufacturer to ensure the screed is suitable for overcoating.

The correct preparation of steel substrate depends on whether it is ferrous or non-ferrous.
Remove corrosion to brighten the steel, treating any stubborn spots or marks with rust converter before applying a primer. If previously painted, all coatings must be well adhered.

Turning to timber, softwood knots should be wiped and sealed using knotting compound or aluminium primer. Resinous hardwoods should be wiped with methylated spirits prior to priming with aluminium wood primer. The moisture content of the timber should be below 15%. Damp wood should never be painted as this will give rise to blistering, flaking, and cracking. Damaged, rotten, and darkened timber should be repaired prior to product application.

When covering previous and existing coatings, if possible, identify the existing product and check its compatibility with any new coatings. Existing coatings should be well adhered to. Any flaking, damaged, or loose material should be removed back to a firm edge. Substrates should be clean, free of oil, grease, and dust and completely dry before application of any product.

Preparation
Clean with high pressure wash and sweep to remove all loose debris. Degrease using an industrial degreaser and rinse. Lightly abrade the surface, blast or acid etch, vacuum to remove all dust, and ensure the substrate is completely dry prior to application of the new coating. With power floated floors, once the surface is cleaned, they can be prepared by vacuum blast, grinding, or diamond grinding, acid etching or the use of adhesion primers.

Application
With product selection and preparation now complete, we can move on to application. The method of application will depend on the product selected and the manufacturer’s instructions. As with any application, it’s important to understand the product’s recoat, drying, and curing times.

This information may be found on data sheets or provided by the product manufacturer.

Remember, most manufacturers will offer onsite and specification help. The old adage holds good: failure to prepare is preparing to fail.
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James Burton is sales manager at Bradite