August 2007

‘Design should be considered at an early stage’

The new headquarters completed in the mid 1990’s for Avon & Somerset Police in Portishead is a typical example of the importance of considering waterproofing at an early stage in new building design.

RIW were contacted by Bruges Tozer to put forward their recommendations for damp proofing the ground floor slabs of the HQ building.

The installation was particularly interesting as the architect wanted to achieve a simple and uniform installation without altering the waterproofing needed for the varying conditions.

The different elements that needed to be waterproofed included: ground floors with finishes ranging from carpet to vinyl, computer rooms with raised access flooring and a lecture theatre below ground level requiring tanking.

RIW Toughseal was applied in situations where the traditional method of using a screed to protect the waterproof membrane could not be used. In areas where raised access floors were required the pedestals where adhered directly to the membrane, avoiding the need for mechanical fixings and inherent danger of penetrating the membrane.

Where suspended wood flooring on wood battens were specified, the membrane was applied to the concrete floor slab, enabling the battens to be fixed directly to the slab.

In both of these situations the elimination of a screed provided benefits in terms of cost and time while allowing the continuity of the membrane to be unaffected.

The ground floor also included pre-cast plank construction. In this situation, movement between individual components was considered a possibility. To overcome this, RIW’s Flexiseal was specified.

Flexiseal is a rubber-like flexible liquid membrane that can accommodate up to 4-5mm of movement without failure of the membrane (Contact our Technical Department on 01344 397777 for more advice).

In more traditional situations where a screed was provided, RIW LAC was used as the damp proof membrane. At all stages care was taken to ensure that continuity of the membranes was achieved despite the differing construction techniques and finished flooring requirements.

The nature of the construction programme required RIW’s technical staff to respond very quickly to the requests for details with information being faxed between the two companies.

RIW also checked all specifications and visited the site to ensure the products were being applied correctly.