Basement conversion – victorian property

The first step was to excavate the floor down as low as the foundations would allow, in order to maximize the available headroom in the basement. Because the foundations were slightly deeper in one room than the other, it was decided to step the floor levels. A new concrete floor-slab was then laid throughout the basement.

Waterproofing of the basement was carried out using the Oldroyd Xv Clear Cavity Drainage Membrane System. This system was chosen over a cementitious or epoxy-based system, as it redirects any water entering the basement, to a sump, rather than physically holding back the water pressure. This means that the system does not rely on the integrity of the soft, Victorian brickwork for it success.

It also allowed the contract to be completed quicker, as there was no need to sand-blast the walls in order to provide a key. An Aquadrain channel was laid around the perimeter of the basement at the floor-wall junction, leading to a sump and pump. This provides additional drainage at what is usually considered to be the area most susceptible to water-ingress in basements.

The Oldroyd Xv Membrane was then applied to the basement walls and floors. Special, self-sealing ‘Oldroyd brick plugs’ were used to fix the membrane to the walls of the basement, whilst on the floor, no fixings were required. Holes in the back of the brick-plugs, designed to accept No.12 screws, allowed battens to be fixed over the membrane. Plasterboard was then fixed to the battens.

New ceilings, lighting, sockets and plumbing were installed, as well as a humidistat-controlled extractor fan. This fan is intended to increase ventilation in the basement and ensure that the levels of humidity do not rise above those recommended for a Grade 3 basement environment in BS8102.