As with many Victorian properties in Cambridge, converting the damp cellar into a usable waterproof room is a great way to increase the habitable space within a property.

APP were asked to carry out an inspection with a view to providing an estimate for a suitable waterproofing solution.

APP specified and installed a cavity drain membrane system with sump pump.

The system uses extruded HDPE membrane with 8mm studs for wall application and 20mm over the floor, which allows water and vapour to move in all directions across the whole of the wall and floor surfaces, thereby achieving damp pressure equalisation.


Drainage channels set within the floor collect any water ingress where it is directed to the sump station and removed to the external drainage.

APP’s carpentry team screwed treated timber battens to the walls, followed by plasterboard and laid a floating timber floor, new skirting boards were then fixed to the walls.

APP also installed insulation in between the ceiling joists followed by a plasterboard ceiling.

The cellar is now a much-improved space and asset to the property which the client was very pleased with.