How to Prepare Walls Before Painting — The Right Way
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How-To15 October 2025· 5 min read

How to Prepare Walls Before Painting — The Right Way

Preparation is where paint jobs succeed or fail. Our Dublin painters explain exactly how we prep walls — and what happens when it's skipped.

Why prep matters more than paint

Premium paint on poor prep fails faster than budget paint on good prep. Preparation does three things: adhesion, smoothness and longevity.

We spend 40–50% of total job time on preparation. It's the part you don't see in photos — and the reason finishes still look right five years on.

Step 1 — Cleaning the surface

Sugar soap solution for interiors. Pressure washer plus mould treatment for exteriors — Dublin's damp climate means most exterior surfaces have biological growth.

Drying time: 24 hours for interiors, 48–72 hours for exteriors before any paint goes on.

Step 2 — Filling and repairs

Hairline cracks: fine surface filler. Larger holes: two-part filler or bonding plaster. Render cracks: flexible exterior filler or sand-cement. Gaps around frames: decorator's caulk — not filler, because caulk flexes with movement.

And yes, we fill nail holes and picture hooks as standard.

Step 3 — Sanding

Sanding smooths filled areas and gives gloss paint a key. We use vacuum sanders on interior work — they capture dust at source, so your house stays liveable while we work.

On woodwork with multiple layers of old gloss, a heat gun is faster and kinder to the timber than chemical strippers.

Step 4 — Priming

Not optional. Primer seals filler and plaster, improves adhesion, and blocks stains.

Stain-blocking primer (Zinsser BIN) on any staining. Standard PVA for new plaster. Exterior masonry primer on bare render. Skipping primer is the most common cause of patchy results on older Dublin houses.

The result of doing it right

All preparation is included in our written quotes, itemised line by line. No surprises on the day. Call 085 821 1870 for a free site visit.

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