Newbuild Basements

Basements are enjoying a resurgence, particularly in residential developments where their benefits had traditionally been overlooked in the UK.

Site Suitability for a Basement

Most sites are suitable for a basement, but it is good practice to commission a geotechnical survey to ensure site suitability. Care should be taken if the survey reveals a permenantly high water table, a high probability of a perched water table or if the site is in a flood risk area. These problems would not rule out a basement but are likely to increase construction and waterproofing costs.

In some cases maps or a site survey will show that there are power cables, sewers, or mains pipes running through the area where the basement is planned. These can often be moved, but in some cases the cost of doing so may prove prohibitive. On brownfield sites soil contaminants and ground gasses can present a problem. Fortunately, some waterproofing systems can provide protection against both of these.

Basement Construction Type

In virtually all cases, the basement slab will be formed of reinforced in-situ concrete. Typically, this is also used to form the basement walls, however other methods of construction can be used - e.g. precast concrete and insulated concrete formwork (ICF) filled with reinforced concrete. On large, commercial basement projects or where the basement is to be constructed close to adjoining buildings diaphragm walls or contiguous/secant piled walls may also be used.

The choice of basement construction type will depend on a number of factors such as site conditions, cost, required performance, and the personal preferences of the designer. A simplified and evaluated design approach can be found in the Approved Document - Basements for Dwellings.^[1]

Waterproofing Newbuild Basements

Deciding on the most suitable waterproofing system for a newbuild basement will depend on a number of factors including:

• Site conditions
• Soil type
• Proposed use of basement
• Basement construction type (substrate material)
• Necessity to protect against soil contaminants / ground gasses

We would suggest that you contact our technical department on 01403 210204 to discuss waterproofing requirements for specific basement projects (alternatively, fill in our enquiry form). However, by way of illustration some typical basement waterproofing solutions are shown on our systems page.

Basement Waterproofing CPD Seminars (RIBA Approved)

Safeguard offer a number of RIBA-Approved CPD Seminars free-of-charge to architects and specifiers on the UK mainland on the subject of basement waterproofing. For further details, please visit our Basement Waterproofing CPD Seminars Page.

References

1. Basement Information Centre . Approved Document - Basements for Dwellings . TBIC, Blackwater, 2004. 87pp. TBIC/001.