Basement Conversions

Many older properties are fortunate to include a cellar, pavement vaults or other below-ground area with potential for use. In their damp, cold and draughty state these are often used for extra storage, however they have the potential to be transformed into a valuable extra room in your property.

Children’s playrooms, home cinemas, wetrooms, kitchens, studies, home gyms and guest bedrooms are just a handful of the extra rooms which clients have achieved using the ADD Waterproofing system. If the form of the structure is not changed planning permission is not necessary but there are a number of building regulations that need to be adhered to. If additional bedrooms are being created lightwells or window egress will have to be installed in which case, planning permission will be required.

Traditional methods of waterproofing such as cement based renders, often referred to as ‘tanking’ are becoming less reliable as water table levels rise and bring increased hydrostatic pressure to bear on properties. The new but increasingly used solution is to apply a polyethylene sheet material described as Cavity Drain Membrane which, provided the substrate is suitable, can be directly applied with little preparation to the walls.

Cavity membrane is impervious to water and provides additional insulation value. Before the membrane is fitted a drainage provision is installed to ensure quick and efficient evacuation of any water ingress which stays behind the membrane. Internal finishes of insulation and plasterboard or plaster and render products are applied in front of the membrane to provide a dry and well insulated living area.

Correctly installed by specialist contractors and with ongoing routine maintenance of drainage channels and pumps, these systems can last the lifetime of the property. In addition to the cavity drain membrane, the ADD Waterproofing system incorporates two air management units.

A unit which draws clean, fresh air into the interior of the basement is installed in the room. The ADD Positive Pressure unit ensures that the air pressure within the room is slightly higher than behind the membrane, so that radon is not drawn through any defects in the membrane which may occur. An exhaust pipe containing an inline fan is installed on the outside of the property to draw air from behind the cavity drain membrane. Any radon which has entered the gap will be extracted and vented away from the building.