What black mould actually is
"Black mould" is the everyday name for the dark grey, green and black colonies that grow on damp walls, ceilings and sealant. In UK homes it is usually a mix of common species that thrive on damp plaster, paint and dust. You do not need a lab test to act on it. If you can see it, it needs removing and the moisture behind it needs fixing.
Is black mould dangerous?
Mould releases spores and fragments into the air. For most healthy adults the effect is irritation: a blocked nose, sore eyes, coughing. The NHS advises that babies, children, older people, people with asthma, allergies or skin problems, and people with weakened immune systems are more sensitive. That is why we never dry brush mould and always contain the work area. Read more in our guide is black mould dangerous.
How we remove black mould
- Find the cause. Condensation, a leak, a cold bridge or penetrating damp. Readings and photos go in your report.
- Contain. Dust sheets down, doors closed, careful wet cleaning so spores are not thrown into the air.
- Remove. Fungicidal wash on all affected areas, plus removal of blown paint and failed silicone.
- Treat. A fungicidal treatment that penetrates the plaster to kill growth below the surface.
- Seal. Stain block primer and an anti mould finish where suitable, so stains do not bleed back through your paint.
When black mould means a bigger problem
Sometimes black mould is the visible end of a wet wall. Mould low down on an external wall that gets worse in wet weather can point to penetrating damp. A tide mark with salts along the bottom of a ground floor wall can point to rising damp or bridged damp proof course. Mould in neat lines along the ceiling edge usually means a cold bridge. If we see any of these, we tell you straight and quote for the right fix, or recommend a damp survey first.
Price and guarantee
Most black mould treatments for a single room cost between £350 and £600 with no VAT added. Every treatment comes with our 6 month written guarantee on the treated surfaces.