Painting & Decorating

Why do yellow stains keep coming through the painted wall despite re plastering?

Anonymous user 03/03/2024 - 3.08 PM

When My son first bought his flat he had to have remedial damp course work done. This was done thoroughly by a reputable company. The extensive procedure entailed the wall being taken back to brick, damp work done, re-rendering and replastering. It was then mist coated repainted after after 3 months. The stains started to come through again and as the shower had leaked, after repairs the wall was taken back to brick, replastered, mist coated and painted. The shower leaked again. This has now been properly corrected, and water damage to the wall remedied, but the yellow stain is back. Why is this coming through still? Is is from the shower leak? Why does it keep coming back despite the extensive remedial work? Its like a rust stain, just not so dark. What can we do before we re-paint after the shower repair?