Basements

Typical failures include:

• failure of the waterproofing system;
• structural failure of the foundation or slab;
• an increase in hydrostatic pressure;
• poor workmanship, leading to poor lapping of the waterproofing;
• condensation on buried pipes or cold bridges, or failure of mechanical extracts;
• poor natural cross-ventilation;
• leaks in pumped waste pipes that can create offensive smells;
• careless installation of mains services;
• the basement appears to be tanked or lined but has only had ordinary render applied (removal is a simple solution);
• damp penetration through front steps (a particular problem with half-basement designs).

Remedial options must take into account guidance provided within BS 7913:2013 Guide to the conservation of historic buildings and include:

• injecting grouts and chemicals into the soil around the foundation walls, under slabs, behind walls, and into leaking cracks and joints;
• alleviating the water pressure;
• altering topographical elements and the use of internal and external drains;
• applying additional internal waterproofing materials.

Note: Any physical alteration involving the above options should be an absolute last resort and subject to agreement with the Conservation Officer.