Delta Cavity Membrane Waterproofing

Basement Cavity Drainage:
Delta Membrane Waterproofing.
Garden Room, London


To provide an effective waterproofing system to a new build basement garden room:

The basement garden room had been formed using a waterproof concrete system. Despite this, water was still able to penetrate into the structure through defective construction joints and areas of honeycombing in the concrete retaining walls.


The new concrete was treated using Koster Polysil TG500. This is an anti free lime coating that prevents limescale formation in the drainage.

Areas of active water ingress through the structure were sealed using Koster KB Flex 200.

Delta MS500 was used as the waterproofing system for the walls. The Delta MS500 was fixed in place using Delta Qwikseal Plugs. The Delta Qwikseal Plugs have a sealed fixing point allowing for the secure installation of timber batten or metal track wall liner systems.

Delta MS20 was used for the floor. Delta MS20 has a high drainage capacity and can be loaded to an impressive 150 kn/m2

Detailing is key. The Delta MS500 is sealed at the soffit using a robust wall-soffit detail. A rounded fillet was formed using Koster Repair Mortar Plus, waterproofed using Koster NB1 Grey and then the MS500 is sealed to the soffit using Delta Corner Strip.

The installing contractor provided a 10 year insurance backed guarantee on the installation.

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