Choosing wall paint: hiding power, wet scrub resistance and sheen

Hiding power class (opacity) and spreading rate under DIN EN 13300

The hiding power (opacity) of an interior paint is classified into four classes under European standard DIN EN 13300: class 1 stands for highest hiding power (at least 99.5 per cent contrast ratio), class 4 for the lowest. Equally important is the spreading rate in square metres per litre stated right next to it — for example class 1 at 7 to 8 m²/l.

Always compare both figures when buying paint. A seemingly cheap class 2 paint at 6 m²/l often requires a second or third coat in practice and ends up costing more time and material than a professional class 1 emulsion paint. When painting over strong old colours or dark feature walls, a base coat is usually still sensible even with class 1.

Wet scrub resistance classes 1 to 5: scrub-resistant or washable?

Wet scrub resistance indicates how well the dried paint film withstands cleaning and friction. DIN EN 13300 defines five wet scrub classes: paints in class 1 and class 2 are rated highly scrub-resistant, class 3 washable, while classes 4 and 5 rub off even when wiped gently with a damp cloth.

For ceilings and low-wear bedrooms and living rooms, wet scrub class 2 or 3 is often sufficient. In busy hallways, stairwells, kitchens, children's rooms, medical practices and offices, wet scrub class 1 or 2 is clearly recommended. For move-out cosmetic repairs in rented flats, scrub-resistant paint also pays off because minor marks can be wiped away before flat handover.

• Hiding power class 1 for streak-free coverage in fewer coats
• Wet scrub class 1 or 2 (scrub-resistant) for hallway, kitchen, stairwell and children's room
• Wet scrub class 3 (washable) for ceilings, bedrooms and living rooms
• Solvent-free, plasticiser-free, low-emission interior paint (e.g. Blue Angel eco-label)

Sheen level and paint type: emulsion, silicate or latex paint

Sheen level affects both the look of a room and how clearly surface flaws show. Matt and dead-matt wall paints hardly reflect raking light, disguise minor imperfections in plaster or woodchip wallpaper and are the standard choice for living spaces. Satin or silk-gloss paints (such as many latex paints) are very easy to wipe clean, but highlight every filled patch and often require Q3 or Q4 wall preparation.

Standard synthetic resin emulsion paint adheres to almost all interior substrates from woodchip wallpaper to plasterboard. Mineral silicate paint (sol-silicate or dispersion silicate) and lime paint are highly vapour-permeable (breathable) and naturally mould-inhibiting thanks to their high alkalinity — ideal for bedrooms, period walls, cellars or moisture-prone rooms with a mineral substrate.

Calculating paint quantity per square metre accurately

Measure the room perimeter (all wall lengths added together) and multiply by the ceiling height. Subtract large window and door openings and add the ceiling area if the ceiling is being painted too. Multiply this total square metre area by the planned number of coats and divide by the spreading rate per litre on the tub.

Worked example: a room measuring 4 by 5 metres with a 2.50 metre ceiling height has around 45 m² of wall area. For two coats (90 m²) at 7 m²/l coverage, you need roughly 13 litres of wall paint plus about 10 per cent reserve for textured surfaces such as coarse woodchip. With custom-tinted colours, always buy the full quantity from a single mixed batch.

What we need for your painting quote

When requesting a quote, let us know the number of rooms, approximate floor or wall area in square metres, desired shade (e.g. off-white / RAL 9010 or custom colour chart shade) and current wall condition. Tell us whether we should supply the trade paint directly and whether ceilings, doors or radiators are to be painted too.

TF Clean carries out interior painting and decorating in flats, houses and commercial premises in Riesa and the surrounding area — including masking, filling, priming and final cleaning. Simply message us via the contact form.