Mould Removal Cardiff: Damp Specialists

Heavy rain and old houses are a common mix in Cardiff. Driving rain soaks solid walls in Victorian terraces, while condensation forms on cold corners of rooms that aren't heated evenly. The treatment depends on which one you have, so diagnosis comes first.

Cardiff at a glance

Homes that are flats: 26.5% of Cardiff households lived in a flat, maisonette or apartment in 2021: 20.2% in purpose-built blocks and 5.0% in converted or shared houses. Another 29.6% lived in terraced houses. Source
Renting: 24.3% of Cardiff households rented privately in 2021 and 17.2% rented from the council or a housing association. Source
Energy ratings: 47.5% of Cardiff homes with an EPC lodged up to March 2022 were rated C or above, so just over half sat at D or below. Among homes built before 1930, only 17.1% reached C. Source
Rain and winter cold: The Met Office station at Cardiff Bute Park recorded about 1,200 mm of rain a year on average over 1991 to 2020. January nights averaged 2.5°C and July days 21.8°C. Source
Nest scheme: Nest, the Welsh Government's scheme, funds heat pumps, insulation and solar panels for owners and private renters on means-tested benefits or low incomes whose home is rated EPC 54 (E) or lower, or 68 (D) or lower where someone has an eligible health condition. Source
Renting rules in Wales: Under the Renting Homes (Wales) Act 2016, landlords must keep a working carbon monoxide alarm in any room with a gas, oil or solid fuel appliance they supplied, and damp and mould are listed hazards when judging whether a home is fit to live in. Source

Rights for renters in Wales

About four in ten Cardiff households rent, either privately or from the council or a housing association. Under the Renting Homes (Wales) Act, landlords must keep the home fit to live in, and damp and mould are named hazards in that test.

Tell your landlord about the mould by email or letter and attach dated photos of each patch. If nothing happens, contact Cardiff Council, which can inspect privately rented homes. Social tenants should use their landlord's repairs line first, then its complaints process.

What a survey should find

A good survey checks gutters and downpipes, pointing and render, ground levels against the damp-proof course, and leaks from plumbing. It should also measure humidity in the rooms and surface temperatures on the walls.

Be wary of a survey that recommends injected damp-proofing from a single moisture meter reading. Meters often over-read on plaster with salts in it, and the real cause is frequently a blocked gutter or condensation.

Cleaning and stopping it coming back

Small patches can be cleaned with a mould remover, following our guide to removing mould from walls. For larger areas, or if someone in the home has asthma, get a specialist.

Long term, steady heating, working extractor fans and insulation stop it returning. Nest can fund insulation and heating upgrades for low-income owners and private renters in poorly rated homes.

Cardiff homes and what they need

Victorian bay-fronted terraces

Bay windows and the walls around them often get damp from failed lead flashings and cracked render. Fix the outside before replastering inside.

Interwar and post-war semis in the northern suburbs

Mould behind wardrobes on outside walls is usually condensation. Pull furniture a few centimetres from the wall and check that cavity insulation hasn't bridged.

Modern apartments around Cardiff Bay and the centre

Newer flats are airtight, so mould here is mostly about ventilation. Check that trickle vents are open and that the mechanical ventilation unit, if there is one, is running and has clean filters.

Areas covered

Engineers who cover Cardiff work across areas including Roath, Cathays, Canton, Pontcanna, Grangetown, Splott, Llandaff, Whitchurch, Rhiwbina and Penarth.

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Questions people in Cardiff ask

Is black mould dangerous?

It can trigger asthma and allergies, especially in children and older people. Treat it promptly and fix the cause.

Will a dehumidifier fix it?

It helps with condensation, especially if you dry clothes indoors. It won't fix a leak or rain penetration. Our window condensation guide explains other quick wins.

Does damp-proof paint stop mould in a Cardiff terrace?

It can hide the symptom for a while on a dry wall. If the wall is wet from rain or a leak, the mould will return through the paint, so find the source first.

Sources

Also nearby: Damp and mould removal in Swansea, Damp and mould removal in Bristol, Damp and mould removal in Gloucester

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