Cavity Drain

Cavity Drain R20 & R7 are used as internal cavity drainage membrane systems, to collect water entering the structure. Cavity Drain R20 and R7 are typically used in basements and sub-structures, to channel water ingress to a sump or collection point for disposal.

Internal Cavity Drainage System

Cavity Drain R20 is a 1mm thick high density polyethylene (HDPE) profiled sheet, with 20mm high studs.

Cavity Drain R7 is a 0.5mm thick HDPE profiled sheet, with approximately 7mm high studs.

When designing Type C structures (as classified in BS8102:2009), the product applied correctly, Cavity Drainage Membrane is capable of providing the levels of protection required for Grades 1, 2 & 3 basements.

Find out more about Cavity Drain R20 here.

Find out more about Cavity Drain R7 here.

Typical Uses of Cavity Drain

Internal Tanking of basements
Sub-structures & retaining walls

Features & Benefits of Cavity Drain

Easy to install to most substrates
Applied to Concrete, masonry, sheet and concrete piled walls
Can be applied to wet substrates
Complete water and water vapour barrier
High compressive strength
Chemically resistant

Cavity Drain Product Calculator

RIW CAVITY DRAIN R20 & RIW CAVITY DRAIN R7

PRODUCT CALCULATOR FOR FIXINGS

Components Required for Full Roll Applications :

WALLS

Membrane	Brick Plugs	Sealing Tape	Sealing Rope
Cavity Drain R20 2.0 x 20m roll.	5 No. per m2 ie ; 2 boxes	---	6 No. rolls
Cavity Drain R7 2.07 x 20m roll	5 No. per m2 ie ; 2 boxes	1 No. roll	2 No. roll

FLOORS

Membrane	Brick Plugs	Sealing Tape	Sealing Rope
Cavity Drain R20 2.0 x 20m roll.	---	---	5 No. rolls
Cavity Drain R7 2.07 x 20m roll.	---	---	1 No. roll

In addition to these components, RIW Overtape will be required, as follows :

RIW Cavity Drain R20

Overtape is used at wall/floor, wall/wall and wall to soffit junctions. It is also used around service penetrations and for sealing over joints when required. Other materials are also adhered to the Cavity Drain products using Overtape.

RIW Cavity Drain R7

Overtape is used at wall/wall and wall to soffit junctions, and outside non-flanged laps. It is also used around service penetrations and for sealing over joints when required. Other materials are also adhered to the Cavity Drain products using Overtape.

Please refer to RIW Cavity Drain R20 & R7 data sheets for further information.

The information above is based on our experience, and is offered for guidance only.