▽ +06.00Paints
Paints and protective coatings
Interior and exterior paints for walls and ceilings, and coatings that protect concrete, steel and floors — from surface preparation to the final coat, to the approved specification and the manufacturer’s data.
The principle
Paint is a system, not just a colour
Paint that lasts is a system of layers: a prepared surface, a sealer or primer that suits the substrate, filler where needed, then finish coats at the thickness the data sheet sets — each layer relying on the one below.
We distinguish two families: architectural paints that give colour and texture and make cleaning easy, and protective coatings that shield concrete from carbonation, steel from corrosion and floors from abrasion and chemicals.
Most paint defects — blistering, peeling, efflorescence — start before the paint itself: moisture in the wall, salts, dust or the wrong primer.
Types
Types of paints and coatings
Interior paints
Water-based (emulsion) paints, matt or semi-gloss, for walls and ceilings, and washable grades for corridors and kitchens.
Exterior paints
Acrylic facade paints that resist UV and dust, and elastomeric grades that bridge hairline cracks.
Decorative and textured finishes
Textured, stone-effect or sprayed finishes for walls and facades, approved on a sample first.
Enamel paints
For doors, metalwork and surfaces that need a hard, glossy film, over a suitable primer.
Concrete protection coatings
Anti-carbonation coatings for exposed concrete, and epoxy and polyurethane coatings where needed.
Anti-carbonationSteel protection coatings
A zinc-rich or epoxy primer and a UV-resistant polyurethane top coat, chosen for the exposure.
Protective coatingsFloor coatings
Epoxy and polyurethane coatings for floors and car parks, with mechanical preparation and moisture checks.
Flooring systemsClear coating for tiles and stone
A clear polyurethane layer that protects tiles and stone and keeps their look.
Clear PU
Preparation
Preparation before the first coat
Moisture
The wall or concrete is checked; a damp or freshly cast surface is not painted.
Cracks and defects
Cracks, honeycombing and joints are treated before painting.
Concrete repair & protectionSalts and efflorescence
Salts are removed and the moisture that carries them is dealt with.
EfflorescenceCleanliness
Dust, oil and weak old coats removed, sanded where needed.
Steel
Rust removed to the grade the specification sets before priming.
Weather
Surface temperature, humidity and dew point within the data-sheet limits.
Application
From the sample to the final coat
Approved sample
A trial area for colour and texture, approved before the rest.
Primer or sealer
A coat that bonds the paint to the substrate and evens out its absorption.
Filler and sanding
Where needed, for an even, uniform surface.
Finish coats
In the number, thickness and recoat intervals the data sheet sets.
Inspection and handover
Uniformity and coverage checked; dry-film thickness and adhesion measured on protective coatings where specified.
Defects
Why paint fails
Blistering
- Cause
- Moisture or salts behind the film, or painting a hot surface.
- Prevention
- Moisture checks, and painting at the right time.
Peeling
- Cause
- A dirty or glossy surface, or the wrong primer.
- Prevention
- Cleaning, sanding and a compatible primer.
Efflorescence
- Cause
- Salts carried to the surface by moisture.
- Prevention
- Treat the moisture source before painting.
Chalking and fading
- Cause
- Interior paint used outdoors, or strong UV.
- Prevention
- A UV-resistant exterior paint.
Cracking
- Cause
- Coats too thick, or movement in the substrate.
- Prevention
- The right thickness, and elastomeric paint over hairline cracks.
Mould and stains
- Cause
- Persistent damp and poor ventilation.
- Prevention
- Fix the damp, and use a paint suited to wet areas.
Questions
Questions clients ask
How many coats does a wall need?
Usually a sealer or primer, then two finish coats; the final number depends on the paint, the substrate and the data sheet.
What is the difference between interior and exterior paint?
Exterior paint is made to withstand UV, heat, rain and dust; interior paint focuses on looks and easy cleaning. Interior paint used outdoors fades and chalks.
Can you paint over old paint?
Yes, if the old coat is sound, well bonded and compatible: it is cleaned, sanded and its adhesion tested; otherwise the weak coat is removed first.
Which coating best protects exposed concrete?
An anti-carbonation coating limits the entry of carbon dioxide and water while letting the concrete breathe; the system is chosen for the exposure and the specification.
When should you paint in a Riyadh summer?
Within the data sheet’s temperature range — often early in the morning or out of direct sun, because a hot surface dries the paint before it bonds well.
How is a protective coating checked?
By measuring dry-film thickness, a pull-off adhesion test (ASTM D4541) where the specification calls for it, and a visual check of uniformity.
Is exterior paint a waterproofing?
No. Some elastomeric paints resist rain and bridge hairline cracks, but they do not replace waterproofing on roofs and walls exposed to water.
Next step
Walls, facades or concrete to paint?
Send photos, areas and the type of surface for a detailed offer, or book an inspection to define the preparation.