Do I need a primer or sealer before painting new plaster in South Africa?

Yes. New plaster is alkaline and highly porous — applying topcoat directly results in patchy coverage, poor adhesion, and wasted paint. A PVA sealer (diluted 1:5 or as directed) seals the surface and neutralises the alkalinity. One coat of sealer reduces topcoat consumption by 20–30% compared to painting directly onto bare plaster. Plascon PVA Sealer and Dulux Superbase are standard SA products. Allow 4–6 hours drying time before topcoating.

What is the difference between Plascon and Dulux paint coverage in South Africa?

Plascon and Dulux are the two dominant paint brands in South Africa. Their coverage rates for equivalent products are very similar: interior PVA emulsions cover 8–10m²/L per coat for both brands on previously painted surfaces. Plascon Nuroof and Dulux Roofguard both cover approximately 4–5m²/L. Exterior wall paints (Plascon Micatex, Dulux Weathershield) cover 6–8m²/L. The main differences lie in texture, sheen levels, and specific product formulations rather than total coverage rates.

Should I add a wastage factor when calculating paint?

Always add at least 10% to your calculated paint quantity for wastage. Wastage sources include: paint left on the roller and in the tray at the end of each coat, brush drips on cutting in, overspray from rollers on adjacent surfaces, and slight over-application on textured surfaces. For rough or heavily textured walls (Rhinolite, sand finish, exposed aggregate), increase the wastage factor to 15–20% because rough surfaces hold more paint per m² than smooth ones.

Paint Coverage Calculator South Africa

🎨 Last Updated: May 2026 · Plascon & Dulux SA Coverage Rates

🎨Paint Coverage Calculator — South Africa

Total Surface Area (m²) Net paintable area after deducting doors and windows

Paint Type

Coverage rate adjusts automatically

Surface Condition

New plaster needs sealing before topcoat

Number of Coats

Wastage Factor

Paint Price (R/litre) — optional Leave blank to skip cost estimate

Total Paint Required (inc. wastage)

—

Net Paintable Area

—

Litres per Coat

—

Coverage Rate Used

—

Total m² (all coats)

—

Estimated Cost

—

Number of Coats

Tin quantities to buy

5 Litre Tins

—

20 Litre Tins

—

1 Litre Tins

—

⚠️ For planning and estimation only. Actual paint consumption varies with application method, texture and brand. Always test coverage on a sample area for critical projects.

SA Paint Coverage Rates — Plascon and Dulux

Coverage rate (or spreading rate) is the area one litre of paint covers in one coat. It varies significantly by paint type, brand, surface porosity, and application method. The table below uses actual published data from Plascon and Dulux South Africa for their most common product ranges.

Paint Type / Product	Coverage Rate	Tin Options	Notes
Interior PVA emulsion (Plascon PVA, Dulux Wash & Wear)	8–10 m²/L	1L, 5L, 20L	Previously painted; new plaster needs sealing first
Exterior wall paint (Plascon Micatex, Dulux Weathershield)	6–8 m²/L	5L, 20L	Two coats minimum for UV and moisture protection
Roof paint (Plascon Nuroof, Dulux Roofguard)	4–5 m²/L	5L, 20L	Thicker coat required for waterproofing — more tins per job
Primer / sealer (Plascon PVA Sealer, Dulux Superbase)	6–8 m²/L	5L, 20L	Dilute 1:5 with water for new plaster sealing coat
Enamel / gloss (doors, trims, window frames)	12–14 m²/L	1L, 5L	Thinner film — higher coverage but less elastic than PVA

New plaster — why sealing matters

New plaster is highly alkaline and extremely porous. Applying topcoat directly wastes paint — the plaster absorbs the first coat like a sponge and the result is patchy. A PVA sealer (diluted 1:5 with water) closes the surface, reduces alkalinity, and cuts topcoat consumption by 20–30%. Always seal new plaster before applying any finish coat, regardless of paint brand.

The 10% wastage rule

Always buy 10% more paint than your calculated quantity. Wastage occurs from paint remaining in the roller tray and on the roller at the end of a coat, cutting-in drips from brushes, slight over-application on texture, and colour matching between tins. For heavily textured surfaces (Rhinolite, exposed aggregate, stone cladding), increase to 15–20%.

Frequently Asked Questions

How many litres of paint do I need per square metre in South Africa?

Plascon PVA interior covers 8–10m²/L per coat on previously painted surfaces, dropping to 6–7m²/L on new plaster. Exterior paints cover 6–8m²/L. Roof paint covers 4–5m²/L. Always add 10% wastage. This calculator applies the correct rate for your chosen product type.

How do I calculate how much paint I need for a room?

Calculate wall area (perimeter × height), subtract doors (1.8m² each) and windows (1.2m² each), divide by the coverage rate, multiply by number of coats, then add 10% wastage. This calculator does all of this from room dimensions — just enter length, width, height and the number of openings.

Do I need primer before painting new plaster in South Africa?

Yes — new plaster is alkaline and very porous. Apply one coat of PVA sealer (Plascon PVA Sealer or Dulux Superbase, diluted 1:5 with water) and allow 4–6 hours to dry. This seals the surface, prevents topcoat absorption, and stops alkali burn. Without sealing, two topcoats on new plaster often give the same result as one coat on sealed plaster — wasting paint and labour.

How much paint does a 5-litre tin cover in South Africa?

A 5L tin of Plascon PVA (9m²/L) covers 45m² per coat. For a typical 4×4m room (37m² net wall area after deductions), one 5L tin covers one coat, or two 5L tins for two coats with 10% wastage. Roof paint at 4.5m²/L: a 5L tin covers only 22.5m² per coat — plan for more tins on roof jobs.

What is the difference between Plascon and Dulux coverage?

Both brands publish similar coverage rates for equivalent products. Interior PVA emulsions: both 8–10m²/L per coat. Exterior paints: both 6–8m²/L. Roof paints: both 4–5m²/L. Differences lie in texture, sheen, durability ratings, and price rather than coverage. Choose based on the specific product's intended use and your surface condition.

Should I add wastage when calculating paint quantity?

Always add at least 10%. Wastage sources include paint remaining on the roller and tray after each coat, brush drips while cutting in, slight extra application on textured surfaces, and colour variation between tins from different batches. For rough or textured surfaces, use 15–20%. It is much better to have a partial tin left over than to run short halfway through a job.

🔧 Related Artisan Tools

→Paint Labour Estimator — Estimate painting labour cost per m² →Developer Paint Coverage Calculator — Full project estimator →All Trades & Artisan Tools