Leak to dry to treated, one company in Welwyn
Welwyn's housing spans timber-framed and Georgian cottages along the historic High Street, 1920s and 1930s Garden City-influenced semis in Digswell and Oaklands, and newer estates around Woolmer Green. Solid walls without a damp proof course, ageing render, and cavity walls fitted with later insulation all trap moisture differently, giving black mould plenty of routes into these homes.
Mould Treatment
Treat and prevent the mould that follows water damage, dealing with the moisture source first. Mould treatment →
Damp Investigation
Tell rising damp, penetrating damp and condensation apart, so the right repair is done once. Damp investigation →
Leak Detection
Trace hidden water leaks without unnecessary damage using thermal, acoustic and tracer-gas methods. Leak detection →
Structural Drying
Dry walls, floors and voids after a leak or flood with monitored dehumidifiers, to completion. Structural drying →
Areas of Welwyn we cover
We treat mould right across Welwyn and its neighbourhoods, including:
- Old Welwyn
- Welwyn Garden City
- Digswell
- Woolmer Green
- Oaklands
- Mardley Heath
- Ayot St Peter
- Ayot St Lawrence
- Codicote
- Tewin
- Datchworth
- Panshanger
- Burnham Green
- Welwyn North
Common causes of mould in Welwyn homes
Old Welwyn's historic cottages and penetrating damp
Many properties along Welwyn High Street and the older village lanes are timber-framed or solid brick with no cavity and often no functioning damp proof course. Rainwater pushes through ageing render, pointing and thatch or tile junctions, tracking inward to appear as black mould on internal walls and ceilings, particularly where later cement renders have sealed in moisture rather than letting it evaporate.
1920s-30s Garden City semis and hidden condensation
The bay-fronted semis and terraces built during Welwyn's Garden City expansion in Digswell and Oaklands have solid or narrow cavity walls that were never designed for modern airtight glazing and central heating. Warm moist air from cooking, bathing and drying laundry condenses on these cold surfaces, producing mould in bathrooms, bedrooms and behind wardrobes pushed against external walls.
Extensions and loft conversions on newer estates
Homes on later developments around Woolmer Green and Mardley Heath frequently have kitchen extensions, en suites or loft conversions added without matching ventilation upgrades. Bathrooms lacking effective extractor fans and rooms with reduced airflow trap humidity, so mould appears around window reveals, in shower corners and on ceilings, often following a past leak that left residual dampness within the structure.
What our customers say
Was lovely working with the team and they did a fantastic and quick job to get all the mould out of my bathroom. Very much looking forward to working with them on other projects around my house!! Thank you for everything and shout out to Karim for being so sweet!
Mariama, via Google
Omg what brilliant service, excellent the cleaner did a very good job was efficient he took his time and cleaned everything, highly recommend S. Bessim…
Susan Bessim, via Google
Amazing company! They responding very quickly. They have a low prices as well, not crazy quotes like from others. Job has been done very quickly and team was very professional. I will use them in the future if I needed. Thanks!
Patryk Gutowski, via Google
Mould problem in Welwyn?
Call 020 3051 8478 or book a mould survey online. We remove mould and fix the cause for homeowners, landlords and managing agents across Welwyn.