Coral Sol & Chuva Waterproofing Primer Coverage: Why It Changes with the Surface
The Coral Sol & Chuva waterproofing primer covers up to 300 m² per coat on sealed walls but only 70 m² on raw render. Why the surface changes it.
The coverage of Coral Proteção Sol & Chuva Fundo Impermeabilizante (waterproofing primer) is not a single number. The technical sheet gives two very different figures for the same pack, because the surface underneath decides how much primer it absorbs.
Coverage by pack and surface
For the 18 L pack:
- Up to 300 m² per coat on walls already sealed or with levelling filler.
- Up to 70 m² per coat on render and concrete block.
For the 3.6 L pack:
- Up to 60 m² per coat on sealed walls or with levelling filler.
- Up to 14 m² per coat on render and concrete block.
The sheet notes that coverage can still vary with the type and condition of the surface and with the colour of the product.
Why the gap is so wide
A sealed wall, or one with levelling filler, has a closed surface that absorbs little, so the primer spreads far. Raw render and concrete block are porous and open, so they drink in much more product on the first coat, which is why the figure drops from 300 to 70 m² on the same 18 L pack. Estimating material from the sealed-wall number on a porous wall would leave you short.
Application that affects the figure
Dilution is 10%: 10 parts of primer to 1 part of potable water. The primer is applied in 2 to 3 coats with a high-pile wool roller, brush or flat brush, with drying 1 hour to the touch, 4 hours between coats and 24 hours final. Keeping the recommended dilution matters, because thinning beyond it changes the film and the practical yield.
Sizing the whole job
The primer is the base for the waterproofing paint, so coverage is planned together with it. When to apply the primer first is covered in Coral Sol & Chuva waterproofing primer: when to use it before painting, the finish paint in Coral Proteção Sol & Chuva waterproof exterior paint, and the case of a fresh render base in waterproofing new plaster without waiting for full cure. The technical bulletins are published at coral.com.br, and the products are sold through the Coral store.