The chapter includes the following:
- Types of constructions that are classed as ‘basements’
- Basement risk management
- Basement design
- Basement construction
Key points
Design – The design teNHBC basementsam should include ‘a qualified specialist who has obtained the Property Care Association ‘Certified Surveyor in Structural Waterproofing’ qualification.’ We have a team of qualified technical reps that can fulfill this requirement and also specify the correct materials to suit each individual job.
Consider the likely ground conditions – it may be necessary to establish the likely level of the water table and undertake long-term water level monitoring.
For habitable accommodation where more than 600mm of ground is being retained, use a combined system comprising two types of waterproofing. Koster type A products and type C cavity drain membrane system.
Registered Installers – ‘waterproofing should only be undertaken by operatives who are suitably trained or qualified’. We have a nationwide network of specialist contractors that have been through our training scheme that can provide guarantees and have the support of our technical team.
Anti-lime treatment – The use of an anti-lime treatment (Polysil TG500) before applying the type C cavity drain membrane system.
Waterstops – The use of waterstops within the concrete construction, our products being the puddle flange to prevent percolation of water through the slab around drainage pipes and Quellband (water bar) used as a waterstop in concrete construction joints.
Main drainage and service plan – Maintenance of the system should be considered i.e. Flushing points of drainage channel and pump maintenance. We recommend flushing points at every change of direction and every 6-8m on straight runs. Our pump partners PPS offer service plans for the pumps, visit their website for more info. Click here
Backed up system – Include backup systems where pumps are used.
