Dealing with damp yourself

Work out which type you have

The fix depends on the cause. Check our guide to identifying damp. Rising damp leaves a tide mark at the wall base, penetrating damp follows the rain, and condensation brings beads of water and mould on cold surfaces in winter.

Misdiagnosis is common, and it is the main reason people pay for treatment that does not work.

Condensation: what you can do

• Run extractor fans while cooking and showering, and for a while afterwards.
• Open windows briefly each day, and keep trickle vents open.
• Keep the home steadily heated rather than in short bursts.
• Dry washing outdoors where you can.
• Leave a gap behind wardrobes and beds on outside walls.
• Wipe condensation from windows and sills in the morning.

If this is not enough, extractors or a mechanical ventilation system may be needed. A surveyor can say which.

Cleaning mould

Wipe surface mould from hard surfaces and dry them. Wear gloves and a mask, and ventilate the room. Mould comes back if the moisture source is not dealt with, so cleaning is a short-term measure. Do not scrub or disturb large areas of mould in a way that spreads it around the room.

What does not help

Painting over damp or mould hides it without fixing it, and it is likely to blister or stain again. Sealing up every vent in a cold home makes condensation worse. Do not accept a quote for injection until a survey has shown that rising damp is the cause.

Penetrating and rising damp

For penetrating damp, clear blocked gutters and repair broken downpipes from the ground. Leave roofs and high work to a professional. Repointing or re-rendering worn walls is a job for a builder.

For rising damp, check whether soil or paving has been raised above the damp proof course, and lower it if so. DIY damp-proof creams and tanking are available, but misdiagnosis is common. Get an independent surveyor before paying for injection, and do not rely on a free survey from a firm that sells the cure.

If you rent

Report damp and mould to your landlord in writing and keep copies. In social housing in England, Awaab's Law sets time limits for landlords: they must investigate significant damp and mould within 10 working days from 27 October 2025. Phase 2, from 30 November 2026, adds further hazards. It does not yet cover private renting, where your council's private sector housing team can inspect.

When to call a specialist

Call a damp specialist if mould keeps returning despite good ventilation, if you see a tide mark or crumbling plaster, or if walls and ceilings stay wet after rain. Check what damp proofing costs before you agree to a quote.