We all learn from our mistakes. However, we thought we would take that theory and let you learn from others' mistakes so you can avoid problems for yourself and the homeowner in the future. Our Technical Team have put together this advice to help you understand real life defects and the issues surrounding them.
Type of Claim:
Water ingress to below ground car park which has a podium slab over the top to support the building(s) above ground.
How does this defect occur?
The podium slab which acts as a structural lid for the underground car park is generally flat, because of this water can collect and drain through to the car park below. This defect is more likely to occur if the area of the building(s) is smaller than that of the underground car park.
How can this be avoided from the outset?
Designers and builders should follow the recommendations within BS 8102 which provides guidance on the construction of basements. Grade 1 protection is required for car parks which allows for some water seepage and dampness, but water pouring in is not acceptable. Ideally a waterproofing barrier will be included but often this is not possible therefore the concrete and junctions should be constructed using appropriate materials or include additives to provide a level of protection. We would also suggest you employ a CSSW qualified Surveyor to assist in the design.
How can this defect be prevented from worsening?
Unfortunately these types of defects are notoriously difficult to resolve and very costly.
What are the early signs of this defect?
Look out for damp staining and ponding water on the car park floor.
Estimated costs of this type of claim: £££
(Key; Low £ - High £££)
Please refer to Chapter 6 of our Technical Manual for further assistance.