Painting & Decorating New Extensions in North London: From First Coat to Final Finish

Decorating a newly built extension requires a different approach to decorating an existing room. New plaster, new timber, and new renders all have specific requirements that differ from previously decorated surfaces — getting these wrong means premature failure and expensive remediation.

New Plaster: The Drying Time Requirement

The most common mistake made when decorating new extensions is applying paint too soon after plastering. New plaster must be allowed to dry thoroughly — the industry minimum is one month per 5mm of plaster thickness, but in practice we recommend allowing 6–12 weeks for a standard skim-coat finish in average UK conditions. Painting before the plaster is dry traps moisture, causes the paint to peel, and in severe cases can cause the plaster to blow.

The Mist Coat

New plaster is porous and thirsty — applying standard emulsion direct to new plaster causes the paint to be sucked in unevenly, producing a patchy result even after multiple coats. The correct approach is to apply a mist coat (emulsion diluted 20–30% with water) as a first coat, which seals the plaster and provides a consistent base for subsequent finish coats. This critical step is often skipped in budget decorating — always confirm it's included in any quote.

Kitchen Extension Decoration

Kitchen extensions typically combine multiple materials — new plasterboard walls, blockwork, existing masonry walls from the original structure, and sometimes insulated panels. Each substrate requires a different primer specification. Our surveyors assess all surfaces before producing a specification that covers every substrate correctly.

We decorate new extensions throughout Hampstead, Belsize Park, Primrose Hill, and all North London postcodes. Call 020 3874 2670.