Damp Specialists

Our customer had a garden flat on Hampstead Heath at the bottom of a heavily sloping hill. The property was a converted Victorian building and the flat was underground to the front leading to a lower level and garden at the rear. The flat had been subject to consistent damp problems over the years and when we removed the plaster from the brickwork the underlying brickwork was literally wet. Though rising damp only rises by about 1 metre because gravity holds it down, this water was penetrating laterally along the brickwork from the street in front.

This type of project is a question of containment. In an ideal world you would get the earth and water away from the outside of the building which would usually dispose of the problem but that’s only possible if you have control of the corresponding outside areas. We didn’t have control in this project so the only available option was to contain it inside. We installed more than one vertical damp proof courses and also two coatings of Sika damp proofing slurry to well In excess of the manufacturer guidelines. Sika is a very high quality product, and if applied correctly will hold back running water (below a certain pressure) for long enough to cure. You can therefore waterproof a basement which is below the water table and actually has water seeping in.

The slurry doesn’t dry, it cures which can take over 7 days and you see this happening as it reacts to the water in the structure over time. Eventually we rendered it with a sand and cement, again with a Sika waterproofer and then finally skimmed a finish.