Condensation and mould in Edinburgh

The short answer

Condensation forms when moist indoor air meets a cold surface. Black mould then grows on that damp surface, typically in corners, behind furniture on external walls, around window reveals and in bathrooms. It is fixed by a combination of reducing moisture at source, ventilating it away, and reducing cold spots — not by wiping mould off and repainting.

What is different in Edinburgh

• Edinburgh's cool, damp winters combined with solid sandstone walls make cold-spot condensation the most common damp complaint in tenement flats.
• Top-floor and gable-end flats have more exposed external wall area and so more cold surface.
• Newer airtight flats in Leith, Fountainbridge and Livingston rely on mechanical ventilation — mould often follows a fan that has been switched off or blocked.
• Blocked original airbricks and sealed disused flues in period property remove ventilation the building was designed around.

What the work involves

Practical measures: extract fans that actually run long enough, trickle vents, drying washing outside or in a vented space, keeping a background level of heat rather than short bursts, moving furniture off cold external walls, and insulating cold spots where feasible.

Rules and consents in Scotland

Installing extract fans and vents does not normally need a warrant. Insulation work to a listed interior or a change to an external elevation can need consent. Rented property must meet the repairing standard, which covers ventilation and freedom from damp.

What commonly goes wrong

Sealing every draught in a solid-wall flat without adding controlled ventilation, which raises internal humidity and makes condensation worse.

What it usually costs

Indicative ranges only, to help you judge a quote. They are not an estimate for your property — only the business doing the work can give you that.

• Humidity-sensing extract fans in the bathroom and kitchen are a low-cost, high-impact change.
• Trickle vents in existing windows are inexpensive; new vents in sash-and-case windows cost more.
• Positive input ventilation units are a mid-range option for whole-flat humidity.
• Internal wall insulation is the most expensive step and needs care in solid-wall buildings to avoid interstitial condensation.

What to do, in order

1. 1Track where the mould appears and whether it is worst in winter.
2. 2Run bathroom and kitchen extract fans during and after use, or fit humidity-sensing units.
3. 3Stop drying laundry on radiators in unventilated rooms.
4. 4Keep a low background heat rather than heating intermittently.
5. 5Pull furniture a few centimetres off external walls to allow air movement.
6. 6Clean existing mould with an appropriate treatment once the cause is addressed.

When you need a professional

A ventilation installer or electrician for fans and vents; a surveyor where mould persists after ventilation is corrected, which may indicate a fabric defect rather than condensation.

Common questions

Do dehumidifiers help?

They reduce humidity and can help significantly in a flat with limited ventilation, but they treat the symptom rather than the cause.

What does condensation and mould cost in Edinburgh?

Edinburgh labour rates sit above the Scottish average, and access is the other cost driver: tenement stair access, scaffolding on a busy street and parking permits all add to a quote. Get three written quotes for the same specification before comparing prices.

How do I find a reliable business for condensation and mould in Edinburgh?

Check the business is trading locally, ask for recent Edinburgh addresses you can look at, confirm public liability insurance and any trade registration, and get the quote in writing. Lothian Property lists independent local businesses and passes your enquiry on with your permission — we do not carry out the work ourselves.

Related pages

• Damp problems

  Telling penetrating damp, condensation and rising damp apart before spending money.

• Ventilation and airbricks

  Extract fans, trickle vents, airbricks and underfloor ventilation.

• Window repairs

  Sash and case overhaul, draughtproofing, and repairs to modern double glazing.