42 Avenue Road luxury housing development. St John's Wood, London

Basement waterproofing system protects luxury housing development from ingress

  • 3 Jun 2016

A Delta Membranes basement waterproofing system has been used to manage and control water ingress at a luxurious residential project in St John’s Wood, London.

Designed by Greenway Architects, the development incorporated a double level basement, with the lower level extending out underneath the garden.

Screen Shot 2016-06-03 at 9.47.26 amContractor Knowles & Associates undertook the following works in regards to the below ground structure:

  • Excavation and formation of a basement
  • Two/three stage underpinning
  • Internal steel staircase frame
  • Piling
  • Mass excavation to spoil
  • Construction of rear extension
  • Below slab drainage
  • Cavity drain waterproofing
  • Insulation and screed
  • Swimming pool shell within lower level basement

Waterproofing the basement

To waterproof the below ground structure, the Delta System 500 ‘type C’ waterproofing system was installed to deal with any water ingress. The system comprises Delta MS500 fixed to the walls and Delta MS20 laid across the floor, sealed with double-sided tape and Delta corner strip tape.

Modular drainage was installed to drain any water build up to a bespoke Delta packaged pump station, which was situated within the RC concrete slab on the lower level basement. The bespoke dual groundwater and surface water sump pump is capable of pumping 1.8l/s, with a total storage capacity of 653 litres.

The pump station collects ground and surfaced water from the basement walls, floor and external light wells. A separate foul pump station was also installed, to deal with the foul facilities within the basement. 

Koster Deuxan 2C was applied to the topside of the soffit, reinforced with a glass fibre mesh, to waterproof the basement lid of the lower level that extends out underneath the garden.

Delta Membrane Systems,
Delta House,
Merlin Way,
North Weald,
CM16 6HR
United Kingdom

Visit Delta Membrane Systems' website

Leave a Reply

Latest news


The Power of Many: national supply, local service from Freefoam

Freefoam has strong ties with contractors, architects and specifiers, thanks to its ‘The Power of Many’ approach.

Posted in Articles, Building Industry News, Building Products & Structures, Cladding, Posts, Restoration & Refurbishment, Retrofit & Renovation, Roofs, Walls


Builders’ Merchants sales confirm strong V-shaped recovery - BMBI

Britain’s builders’ merchants sales to builders and contractors bounced back strongly in the three months May to July, as reported in July’s BMBI report.

Posted in Articles, Building Associations & Institutes, Building Industry News, Building Products & Structures, Building Systems, Landscaping, news, Posts, Research & Materials Testing, Timber Buildings and Timber Products


New GAI fire door safety guidance launched for local authorities and housing associations

Local authorities and housing associations can now access free guidance on self-closing devices for fire doors, as the GAI has launched a new door closer safety checklist.

Posted in Access Control & Door Entry Systems, Architectural Ironmongery, Articles, Building Associations & Institutes, Building Industry News, Building Products & Structures, Doors, Health & Safety, Innovations & New Products, Publications, Security and Fire Protection

Energy Carbon