Basement conversion project at a Victorian house near Manchester, UK

The basement to be converted was in a two-story Victorian double-fronted property, built circa 1860. The basement consisted of two basement rooms and a wide hall. The owner wished to use this space to create a playroom, a guest bedroom, and a wet room.

The Basement Conversion

The basement conversion was carried out by Remedial Treatment Consultants of Blackpool. 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 its success. It also allowed the contract to be completed more quickly, as there was no need to sand-blast the walls in order to provide a key. An Aquadrain drainage 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 relative humidity do not rise above those recommended for a Category III basement in BS 8102.

The Result

Jamie Willacy of Remedial Treatment Consultants was very happy with the system and went on to say that “our customer was overjoyed and has already recommended us to two friends”.