What conditions do you need to paint indoors?

2 September 2026 3 min read

Quelles conditions pour peindre en intérieur ?

Before it is painted, a surface must be clean, dry and sound, then properly prepared — we come back to this below.

Once these conditions are met, what are the general recommendations for painting indoors? Here is our advice for the best possible application:

1. General recommendations for painting indoors

The ambient temperature should be between 10°C and 25°C.
If the weather allows, air the room before painting.
Relative humidity should not exceed 60%.
Avoid very wet spells or steamy conditions.
The surface must be perfectly dry at the time of application.
Also check the moisture content within the surface itself.
Always stir the tin before use, slowly and by hand, with a clean stirrer.
Clean your tools with water after each use.
Between coats, wrap your tools (brushes, rollers) in airtight plastic such as cling film to stop them drying out.
For an even application and good opacity, use a suitable tool (a roller), work in criss-cross strokes and avoid overloading the tool.

2. How do you prepare an interior surface for painting?

This step is essential: paint does not adhere in the same way to every surface. Here are our recommendations by surface type:

Bare walls

Plaster or plasterboard: fill any holes, then apply an undercoat to harden and even out the surface.
→ Recommended product: Argile sous-couche de préparation

Wooden surfaces

Sand, dust off, clean, repair and degrease where necessary.

Hardwood, wood-based boards (melamine, laminate, MDF), varnished or lacquered surfaces: sand + primer
→ Recommended product: Argile primaire universel
Old woodwork rich in tannin, varnished or coated with old resins: apply a specific bonding primer or a solvent-based primer (not available from Argile)

Bare, smooth and hard surfaces

Plastic, wall tiles, ceramic tiles, non-ferrous metals: clean, degrease, sand and dust off, then apply a primer.
→ Recommended product: Argile primaire universel

Previously painted surfaces

Make sure the existing paint is sound and firmly attached. If there are blisters, cracks or flaking, sand or scrape back the defective areas, fill them, then apply the appropriate preparation product.

Radiators

Already painted and in good condition:
→ Apply Argile primaire universel
Metal, cast iron or stripped back to bare metal: apply a specific anti-rust treatment (not available from Argile)

Furniture

De-wax (remove the wax with a stripper), sand back any old varnish, then apply
→ Argile primaire universel

3. Argile preparation products for interior paint

1. Argile primaire universel (alkyd and acrylic)

Ideal for:

Old gloss or satin paint
Wood and wood-based boards
Non-ferrous metals
Difficult surfaces (PVC, hard plastics and similar)

For ferrous metals: use a suitable anti-rust primer (not available from Argile)

2. Argile sous-couche de préparation (alkyd and acrylic)

Goes on easily over:

Absorbent interior surfaces: plaster and plasterboard
→ After cleaning, sanding and dusting off
→ Can be thinned (5 to 10%) on very absorbent surfaces