Leaks into basements and cellars can be notoriously difficult to locate and resolve.
The tanking here will be in either a waterproofing membrane which is supported internally (normally by brick or blockwork) to prevent it collapsing under the pressure of groundwater. Alternatively, it may be in a waterproof concrete (eg Caltite).
Older basements simply deteriorate as a result of movement over the years or the exposure to groundwater, decades can also take its toll. On occasion, however, the problem is caused simply by a burst main or sewer.
Modern structures with basement areas incorporate a more sophisticated form of tanking which should be resistant to water penetration of any kind. It is essential, therefore that steps are taken during the construction phase to ensure that the waterproofing is installed correctly and integrity tested, such electronic leak detection, by a competent test house such as Thornton Consulting.
Other problems arise from leaks into basements from above, caused by any of a number of issues, from leaking pavement lights to defects in the above-ground structure. We have gained much experience in determining such factors over the past 30 years.