Bath Damp and Mould: World Heritage Terraces and Lime-Based Repairs

Bath's rental stock is dominated by Georgian terraces built from honey-coloured limestone, much of it inside a UNESCO World Heritage Site. The figures below are for Bath and North East Somerset, which includes the city and a large surrounding area, and show about 15,300 privately renting households. For landlords, the issue is not whether to fix damp but how to fix it without damaging a protected building.

Bath and North East Somerset in numbers

• Private rented households: 19.3% (England 20.5%); social rented: 14.3% (England 17.1%)
• Terraced homes: 27.2% (England 23.0%); flats: 20.6% (England 21.4%)
• Homes with no central heating: 1.1% (England 1.5%); overcrowded households: 2.2% (England 4.4%)
• River or sea flood risk: 2.0% (England 1.9%); surface-water risk: 3.6% (England 5.9%)
• Rainfall: about 830 mm a year at Beechen Cliff, roughly a mile from the centre

Can I treat damp in a listed Georgian house the way I would in a modern one?

Often not. Listed building and conservation area status limits remediation options, and traditional limestone walls are built to absorb and release moisture. Cement-based renders, waterproof coatings and some injected treatments can trap water in the stone. Before work, find out whether consent is needed, and take advice from a surveyor who knows historic buildings.

Ventilation and lime first

In Bath, internal ventilation and lime-based repairs are the usual approach. In practice that means:

• Lime mortars and plasters that let the wall breathe, in place of cement
• Clear gutters, hoppers and downpipes, with leaks mended promptly
• Extraction in kitchens and bathrooms, so moisture is removed at source
• Lowered external ground levels or drainage where soil is banked against basement walls

Wet climate, low overcrowding

With around 830 mm of rain a year and overcrowding at half the England rate, building defects and weathering are likelier culprits than packed households. Terraced homes, at 27.2%, are above the England share, and rain-exposed stonework and leaking rainwater goods are the first things to inspect.

What landlords must do

The Homes (Fitness for Human Habitation) Act 2018 requires a rented home to be fit to live in. A private tenant can ask the council's housing or environmental health team to inspect damp and mould, and heritage status changes how the repair is done, not whether it is done.

Awaab's Law currently applies to social housing, with private landlords expected to follow. Our guide to Awaab's Law and the private rented sector explains the current position.

To find a specialist, see our Bath damp and mould page.