A brownfield site - a former vehicle repair workshop - was being converted into a dwelling. The local authority required a gas membrane to be installed and independently verified to protect from any possible VOCs and other pollutants in and around the building.
Anglia Property Preservation Ltd provided a specification for the project that combined waterproofing with ground gas remediation as well as providing an insurance-backed installation guarantee.
A cavity drain membrane system was chosen for the damp-proofing as it offered significant advantages over cementitious coating systems.
The Delta system is an extruded HDPE membrane with 8/20mm studs, which allows water vapour (dampness) to move in all directions across the whole of the wall and floor surfaces, thereby achieving damp pressure equalisation. Weak spots are therefore eliminated.
All brickwork was sandblasted to remove paint. The mortar joints were then raked out and repointed with Koster Repair Mortar Plus and SB Bonding Emulsion.
The original flooring was broken up and a new concrete floor laid to the architect’s specification with a channel formed along the side where the wall was earth-retaining for the Delta drainage channel to be fitted in.
A Koster Polysil TG500 priming coat was applied to the concrete slab and 2 coats of MemTech Pro LGB, continued up the wall for 1.5m, to prevent against ground gas ingress.
Delta MS 500 membrane was applied to the walls and fixed with sealed brick-plugs. These can have battens attached to them so there is no need to pierce the system further.
The Delta drainage channel was installed along the retaining wall with a flushing point at the end of the run.
Delta MS20 studded membrane was laid over the floor and sealed to the wall membrane.
Anglia Property Preservation was able to provide both a damp-proofing and ground gas protection system on time and on budget to this project. Throughout the project they worked closely with the architect and lead contractor to ensure the project ran smoothly and that an independent verification certificate for the gas barrier installation would be obtained.