London, United Kingdom

CJ O’Shea and Co. Ltd, are building a stunning new development at Asquith Spencer Park, comprising of four new homes designed by Chassey and Last Architects for Landview Properties, set within acres of rural scenery close to Wandsworth Common. Each home covers in excess of 425 square metres, with a lower floor basement, plus four additional floors above ground, together with associated landscaping and parking.

On completion, the basement area will provide an extensive cinema and games room, together with a utility room and guest bedroom. The concept is to give the homeowners a seamless blend of high-end technology with refined family living.

Asquith Spencer park London watertight concrete project
Asquith Spencer park London watertight concrete project

Project Requirements

A cost effective watertight solution for the basement was required, that would ensure complete watertightness and adhere to the principles laid out for Grade 3 of BS 8102:2009.

Sika Solutions

During the design development, CJ O’Shea chose a dual system from Sika Limited. This consisted of SikaProof® A, a totally new concept in membrane barrier systems, together with the Sika® Watertight Concrete system.

The membrane surface of SikaProof® A is embossed with a grid pattern, which contains a sealant, and is topped by a thin layer of fleece which forms a mechanical bond to the concrete when it dries. The grid pattern is also unique. It offers additional protection, due to the integrated sealant, which bonds tightly with the surface of the concrete, forming mini watertight compartments. Therefore, even if the membrane is damaged or pierced, moisture or pressured water cannot spread between the membrane and the concrete structure as it is contained within the small damaged grid square. In this ‘belt and braces’ construction, Sika® Watertight Concrete system is also being used for all basement construction.

Watertightness of the concrete is obtained by incorporating powerful, state-of-the-art, Sika admixtures in the mix. Hanson Concrete supplied 400m3 of Sika Watertight Concrete to the project. Joints were sealed using the BBA approved SikaSwell® jointing system, which consists of joint sealing profiles that expand on contact with water.

"We choose the Sika waterproof concreting system for this project because the Sika name is synonymous with providing quality waterproof concreting systems with a guarantee to back it up. Having looked at a number of other waterproofing solutions Sika was by far the most practical and cost effective solution for our project." Mr Jim Smith, Owner