Painting Material & Coverage Science
Unlock the secrets of paint coverage ratios, the role of primer in adhesion, and the volumetric needs of wall putty.
The Golden Rule of Coverage
Paint quantity is determined by the Coverage Rate (Square feet per liter). This rate varies drastically depending on the porosity of the surface. A fresh, naked concrete wall will "drink" much more paint than a wall that has been sealed with putty and primer.
Calculated Coverage Standards (Per Liter)
- Primer: $100$ - $120$ sq.ft. (Excellent for sealing pores).
- Interior Emulsion: $120$ - $140$ sq.ft. per coat on smooth walls.
- Exterior Apex/Weatherproof: $50$ - $70$ sq.ft. per coat (Thicker and rougher).
- Wall Putty: $10$ - $15$ sq.ft. per kg (for $2$ coats).
Painting Steps
1. Surface Prep: Sanding and cleaning.
2. Putty: $2$ coats to fill indentations and level the surface.
3. Primer: $1$ coat to provide a bonding surface for paint.
4. Finish Coats: $2$ to $3$ coats of final color for depth and durability.
Why Primer Matters
Skipping the primer might save money upfront, but you will end up spending more on expensive top-coat paint. Primer is cheaper than paint and acts as a barrier, preventing the wall from absorbing the finish paint unevenly, which results in "flashing" or blotchy patches.
Frequently Asked Questions (FAQ)
What is 'Washable' paint?
Higher-end interior emulsions are formulated with acrylic resins that create a hard, plastic-like film. This allows you to wipe off stains with a damp cloth without removing the paint itself. These usually have a slightly lower coverage rate as the film is thicker.