Olympic Construction » Below Ground/Basement

Below Ground/Basement

Basement / Cellar Conversions

Now more than ever there is an ever increasing demand for using every available usable space within your home. The result of the need for space has created an extensive and wide spread demand for the conversion of basement areas into dry, ventilated usable rooms.

Your home is likely to be the most expensive thing you will ever buy, this why it is of the upmost importance that you entrust your basement conversion to a Qualified Water proofing design specialist and not a general builder, getting it wrong can cost you thousands, and leave you with an expensive hole in the ground!


There are a variety of methods which can be used to waterproof basements and other below ground structures. The type of system we use depends on many factors, which include the construction of the building and the level of ‘dryness’ which is required. Nothing is absolutely dry. Water and water vapour will always exist bound up in the building and in the air. However, a building will be perceived as being dry if the water present does not pose a problem for the inhabitant or contents of the building, or cause damage to decorations.

Basically two ways of keeping an existing basement free of ground water; keep the water out, or divert the water away.

Keeping the water out of the basement involves ‘tanking’. Tanking (derived from ‘water tank’), involves application modified renders and slurries applied to the internal face of the structure, to seal the walls and floors.

This can be very effective and we sometimes use this method. However, because they stop water at the point of entry, pressure can build up behind the membrane and it is of the upmost importance, that the substrate is capable of accepting the induced stresses that result or the system will fail.

In the case of the wall area to the left the contractor, applied the tanking Over a very poorly, prepared finish, leaving the old paint on the wall and Didn’t rack out the mortar joints, when a head of water came to bear the System simply delaminated from the wall and the basement flooded. When a tanking system is installed to the walls only, the water pressure will act against the floor, in this case it popped, like a champagne cork, flooding the basement.

It always pays to get a qualified waterproofing designer in who is a member of the PCA http://www.property-care.org/ProGuidance.RWDS.asp

Cavity drain membranes are polyethylene sheets with moulded dimples, creating a cavity between the membrane and the substrate. Ingress water will enter the structure and run inside the cavity to a convenient point for removal by drainage or pumping.

Cavity drain membranes, do not stop water at the point of entry, and so do not increase stresses in the substrate as can happen with cementitious systems.

Diverting water away from the basement is also known as water management, this is also a very effective and increasingly used method.

Cellar Conversions North West

Convert your cellar into an additional bedroom, games room, home gym or simply use for storage space.

Property Care Association member Olympic Construction are market leaders in providing basement Conversions in Oldham, Manchester, Rochdale, Stockport & Cheshire. Our work is backed by the Guarantee Protection Trust. http://www.gp-insurance.co.uk/

Are you faced with an ever-increasing need for more space in your home? Well, you could be standing over it!