Damp Proofing Hammersmith

Hammersmith runs from the Thames at Hammersmith Bridge up through Brook Green and Ravenscourt Park towards Shepherd's Bush. The southern half sits on river gravels close to the Thames, while the streets further north sit on London Clay. The lost Stamford Brook once crossed the area on its way to the river near Ravenscourt Park, and some streets along its old course still collect water after heavy rain.

The housing is varied. Along the river, Upper Mall and Lower Mall have Georgian and early Victorian houses with cellars and riverside walls. Brackenbury Village, Brook Green and the streets around Ravenscourt Park are mostly Victorian and Edwardian terraces built with solid brick walls. There are also large mansion blocks, purpose built council estates and plenty of houses converted into flats.

In the Victorian terraces, rising damp is one of the most common problems we see. The original damp proof course is often slate or bitumen that has broken down, and it is frequently bridged by raised front paths, rear patios and rendered plinths. That leaves salt staining, tide marks and crumbling plaster along the bottom of ground floor walls, especially in hallways and front reception rooms.

Penetrating damp is just as common. Hammersmith terraces have parapet walls, bay roofs and valley gutters that leak when flashings fail or gutters block with leaves from the many street trees. Rain then soaks into solid walls that have no cavity to stop it. Thermal imaging and moisture readings let us trace the water to its source before we recommend any work.

Chimney breasts are another frequent source of damp patches in Hammersmith homes. Many fireplaces were blocked up decades ago and the chimney pots left uncapped, so rain runs down the flue and soaks into the brickwork. Years of coal fires also left hygroscopic salts in the chimney masonry, which pull moisture from the air and keep stains coming back through new paint. Capping and venting the flue and replastering with a salt resistant system usually solve it.

Riverside homes face a different problem. Houses near the Thames sit close to a water table that moves with the river, so cellars and lower ground floors along the Malls and around Fulham Palace Road can take on water through walls and floors. These spaces need a waterproofing system designed to BS 8102 rather than a standard damp proofing treatment.

Under the floors, many terraces have suspended timber floors that rely on air bricks for ventilation. Extensions, raised patios and blocked air bricks cut off that airflow, and the result is damp joists, wet rot and a musty smell. We check the subfloor void as part of every survey where floors are timber, because it is often where the most expensive damage starts.

Condensation and black mould are a frequent issue in Hammersmith flats, from converted houses to mansion blocks and estate flats. Cold solid walls, small kitchens and bathrooms without extract fans, and drying washing indoors all add moisture that settles on the coldest surfaces. Better ventilation and extraction usually fix the problem for good, and we explain the options in plain terms.

Hammersmith is in the London Borough of Hammersmith and Fulham, and much of the riverside and Brook Green area is in conservation areas. Internal damp treatments rarely need planning permission, but external changes to render, front walls or windows may need consent, so we flag them in our report. Every job starts with a survey by a CSSW and CSRT trained specialist, who finds the cause before recommending a fix.