Paints, Primers, Coatings & Waterproofing Used-For Guides

What Paints, Primers, Coatings & Waterproofing covers

This section covers paint systems and protective coatings: PVA and acrylic paints, enamels, primers, bitumen products and waterproofing materials.

The single most useful idea here is that paint is a system, not a product. A finished surface is normally three layers doing three jobs: a primer that bonds to the substrate and gives the next coat something to hold, an undercoat that builds and evens the surface, and a topcoat that provides colour and takes the weather. Skipping the primer is the most common reason paint fails, and it fails months later rather than immediately, which is why the lesson takes so long to learn.

The second idea is that the substrate decides the product. Bare plaster, previously painted plaster, raw timber, galvanised steel and concrete all want different primers. A tin that says “primer” is not universal, and using the wrong one produces adhesion failure that looks exactly like bad paint.

Waterproofing sits here too, and behaves differently again: it is about managing water at joints, upstands and details rather than covering an area. Most waterproofing failures happen at edges and penetrations, not in the middle of a surface.

Browse individual used-for guides

A

• A Nail Primer used for
• A Primer In Makeup used for
• A Primer Paint used for
• A Primer used for
• Acrylic Paint used for
• Acrylic Pva Paint used for

B

• Bitumen used for

C

• Cci 450 Primers used for
• Chalk Paint used for
• Clear Lacquer Spray Paint used for
• Clear Marking Paint used for

E

• Eggshell Paint used for
• Enamel Paint used for
• Etch Primer used for

F

• Face Primer used for

G

• Gentian Violet Paint used for
• Glitter Primer used for
• Gloss Enamel Paint used for
• Gouache Paint used for

H

• High Build Primer used for
• High Gloss Paint used for

L

• Lash Primer used for
• Latex Paint used for
• Low Sheen Paint used for

M

• Makeup Primer used for
• Milk Hydro Grip Primer used for
• Mixing White Acrylic Paint used for

N

• Nail Primer used for

O

• Oil Based Primer used for

P

• Paint Primer used for
• Paint used for
• Plastic Paint used for
• Powder Paint used for
• Primer Paint used for
• Primer used for
• Pva Paint used for

R

• Red Oxide Paint used for
• Rubber Paint used for

S

• Sealer Paint used for
• Spray Paint used for

T

• Tempera Paint used for

U

• Undercoat Paint used for

V

• Varnish used for
• Vinyl Paint used for

W

• What Primer used for

Most searched questions in this topic

• Primer used for
• Pva Paint used for
• Acrylic Paint used for
• Acrylic Pva Paint used for
• Bitumen used for
• Enamel Paint used for
• Nail Primer used for
• Primer Paint used for

How the guides in this section differ

Primer, undercoat or topcoat. Three different jobs. The guides say which layer a product belongs to, because that determines whether it can be used on its own.

Water-based or solvent-based. PVA and acrylic paints are water-based: low odour, easy cleanup, quick recoat. Enamels are traditionally solvent-based: harder wearing on trim and metal, longer drying, needs ventilation and turpentine or mineral spirits for cleanup. Water-based enamels now exist and behave differently again.

Interior or exterior. Exterior products are formulated for ultraviolet light, moisture and thermal movement. Interior paint outside fails quickly, often within a season on a sunny South African elevation.

Decorative or protective. Bitumen and waterproofing products are protective systems with specific application requirements — surface preparation, membrane laps, upstand heights — rather than something you simply brush on.

Layer or product	Job	Common failure
Primer	Bonds to the substrate, seals porosity	Skipped, or wrong type for the surface
Undercoat	Builds and evens the surface	Omitted on a colour change
Topcoat (PVA / acrylic)	Colour and weather resistance on walls	Interior grade used outdoors
Enamel	Hard finish for trim, doors, metal	Applied over an unprepared or glossy surface
Bitumen / waterproofing	Keeps water out	Detailing at edges and penetrations

Related topics and alternatives

• Explore Timber, Boards & Woodworking Materials
• Explore Structural & Masonry Materials
• Explore Plaster, Drywall & Interior Finishing

• Browse all Construction Materials guides

Safety, accuracy and next-step checks

These guides explain what products are for. They follow manufacturer technical data, and where a manufacturer’s specification differs from a general rule, the specification wins.

Points worth carrying:

• Preparation is most of the result. Clean, dry, sound and properly keyed surfaces matter more than the brand of paint. Loose or chalky material must come off first.
• Do not paint over damp or efflorescing walls. Rising or penetrating damp will push new paint off. Find and fix the water source first; painting over it hides the symptom while the problem continues.
• Ventilate, especially with solvent products. Work with windows open, take breaks, and stop if you feel light-headed. Fumes accumulate in enclosed rooms faster than people expect.
• Check compatibility with what is already there. Some coatings lift or wrinkle older layers. Test a small area before committing.
• Respect the recoat time. Overcoating too soon traps solvent and causes wrinkling; leaving it too long can affect adhesion between coats.
• Old paint may contain lead. In buildings painted before the 1990s, sanding old coatings can release lead dust. Take advice before disturbing it, particularly with children in the house.
• Wear appropriate protection. Eye protection when spraying or working overhead, gloves, and a suitable respirator for spraying rather than a nuisance dust mask.
• Store and dispose of properly. Do not pour leftover paint or solvent down a drain; use a municipal disposal point.

Frequently asked questions

Do I really need a primer? On bare, porous, chalky or previously unpainted surfaces, yes. Primer is what the topcoat bonds to, and skipping it is the usual reason paint peels later.

What is the difference between PVA and acrylic paint? Both are water-based. Acrylic binders generally give better durability, flexibility and weather resistance, which is why exterior products are typically acrylic. PVA is common for interior walls and ceilings.

Can I use interior paint outside? No. It is not formulated for ultraviolet exposure and moisture, and typically fails within a season.

Why is my new paint peeling? Most often preparation: a dirty, chalky, glossy or damp surface, or a missing primer. Occasionally incompatibility with an existing coating. Peeling in a defined patch usually points to a damp source.

How long before I can recoat? Follow the tin. It varies by product, temperature and humidity, and recoating early causes more problems than waiting.