Damp Proofing St Albans

St Albans is one of the oldest towns in England, growing up beside the Roman city of Verulamium and around the abbey that became its cathedral. The historic centre around St Peter's Street, Holywell Hill and Fishpool Street has timber framed, Georgian and early Victorian buildings, while Fleetville, the Camp and the streets near the station are mainly Victorian and Edwardian terraces, with 1930s and post war houses further out in Marshalswick and Jersey Farm.

The town sits on chalk, but across much of the higher ground the chalk is covered by clay with flints and other glacial deposits. Chalk drains freely, while the clay above it holds water, so drainage can change from one street to the next. Down in the valley of the River Ver, below the cathedral and around Verulamium Park, the ground is wetter and the water table is higher.

The oldest buildings in the centre have walls of flint, soft brick or timber frame with infill panels, built with lime mortar and no damp proof course at all. They manage moisture by letting walls breathe. When they are later covered in cement render, cement pointing or modern plaster, moisture gets trapped and damp appears that the original construction never suffered from.

Much of central St Albans is a conservation area and many buildings are listed, so treatments have to suit the fabric. We favour lime based repairs, correcting ground levels and improving drainage over chemical injection in these buildings, and we can provide the detail needed for listed building consent.

Cellars are common under the older town centre properties, especially in the streets around the cathedral and the market. They are often used for storage or converted into living or commercial space, and making them properly dry usually needs a cavity drain membrane designed to BS 8102:2022.

The Victorian and Edwardian terraces have solid brick walls and suspended timber floors. Typical faults include damp proof courses bridged by raised paths and patios, blocked air bricks leading to damp floor voids and wet rot in joists, and penetrating damp from worn pointing and blocked gutters.

In the 1930s and post war houses, cavity walls are the norm. Cavity wall insulation, rubble left in the cavity and failed wall ties can all carry water across to the inner leaf, which can look like rising damp but needs a different fix. Condensation and mould are also common in kitchens, bathrooms and bedrooms where extraction is poor.

We also see a lot of damp in extensions, where a kitchen or garden room has been built against the original wall and bridged its damp proof course, or where the junction between old and new roofs lets water in.

Chimney breasts in the older houses are another frequent cause, where flues have been blocked without ventilation and salts build up in the brick.

Because the right answer depends on the age and construction of the building, the survey always comes first. Our CSSW and CSRT trained surveyors take moisture readings, use thermal imaging where it helps, and check drainage, pointing, ground levels and ventilation before recommending anything. You get a written report with photos that explains the cause in plain language and sets out the fix, with no obligation.

We cover St Albans and the surrounding AL postcodes, including the city centre, Fleetville, Marshalswick, Jersey Farm, St Stephens, Harpenden and London Colney. Surveys are arranged from our Hertfordshire office at 58 Western Road, Tring.