Why There Is No Such Thing as "Universal Paint"#
On building sites, there is an understandable wish for simplicity: one single drum of paint that could coat ceilings, exterior walls, window grilles, and timber rafters. But physics and chemistry make universal paint impossible.
Every building substrate has unique physical behaviors. Sand-cement plaster is porous, rigid, and strongly alkaline. Timber is organic, fibrous, and constantly swells and contracts as air humidity shifts between the dry season and monsoon rains. Steel is non-porous, highly dense, conducts heat rapidly, and rusts vigorously the moment bare iron meets water and oxygen.
If you coat wood with a rigid wall paint, the paint cracks when the timber expands. If you apply wall emulsion to bare metal, the water in the paint immediately triggers flash rusting. Coating specification must begin with substrate diagnosis.
1. Interior Cement Plaster and Drywall#
Internal walls constructed of sand-cement render, lime plaster, or gypsum drywall require coatings that allow breathability while providing cleanability.
- Substrate Profile: High alkalinity when fresh (pH 11–13), moderate porosity, sensitive to surface scuffing.
- Required Primer: Alkali-resistant masonry primer for plaster; PVA gypsum sealer for taped drywall.
- Recommended Topcoat: High-opacity acrylic emulsion in vinyl matt, silk, or eggshell finish.
2. Exterior Masonry, Quarry Stone and Render#
Exterior facades in Kenya face fierce thermal cycling: baking in intense afternoon sun, then cooling rapidly during evening rain. Plaster micro-cracks form naturally under this strain.
- Substrate Profile: High moisture exposure, driving rain, fungal and algae growth potential, thermal expansion.
- Required System: Exterior penetrating primer followed by pure acrylic or silicone-fortified exterior weather-guard coatings. These provide UV resistance and elasticity to bridge hairline cracks.
3. Wood and Architectural Timber#
Whether you are finishing cypress doors, mahogany cabinetry, or outdoor cedar pergolas, timber requires specialized treatment from our Wood Finishes & Varnishes selection.
- Substrate Profile: Anisotropic moisture movement (expands across grain), presence of natural tannins and resins.
- Interior Woodwork: Sanding sealer followed by clear polyurethane varnish (matt, satin, or gloss) to resist drinks, grease, and scratching.
- Exterior Timber: Deep-penetrating alkyd wood stains with UV blockers. Hard brittle varnishes should never be used outdoors; they crack and flake when the wood moves, allowing water underneath.
4. Ferrous and Non-Ferrous Metals#
Structural steel, gates, security grilles, and metal window frames require an engineered anti-corrosion barrier from our Metal Primers & Industrial Coatings range.
- Mild Steel & Wrought Iron: Must be wire-brushed or ground to remove mill scale and red rust, degreased with solvent, primed with zinc phosphate or red oxide primer, and finished with two coats of polyurethane or silicone alkyd gloss enamel.
- Galvanized Iron Sheets & Pipes: Fresh galvanizing carries oily passivating oils. Clean with galvanized iron cleaner, apply an etch primer or direct-to-metal (DTM) wash primer, and then coat with acrylic roof paint.
