Ardex SRO 834 Waterproofing Specification - Retaining Walls
Single Layer, Bituminous Sheet Membrane - Protected
Single layer, bituminous membrane system applied in
sheets to approved substrates to form a fully bonded, protected continuous
barrier on retaining walls against water penetration.
This single layer membrane system is suitable for
situations where the likelihood of water penetration is low such as:
On the positive
side of retaining walls with foundations above the permanent water table
basement walls above the permanent water table level.
Suitable substrates for this membrane include:
Brick walls with
render smoothing coat.
Substrates to which the bituminous sheet membrane are to
be applied must be structurally sound and free of all contaminants (e.g.
laitance). The substrates must have completed the recommended minimum
curing/drying periods (e.g. 28 days for concrete) with all holes/voids filled
with cement based patching mortars (e.g. ARDEX BR120FC / ARDEX BR340 system)
and all surface protrusions ground flat. All internal corners are to be shaped
with a cement based coving fillet (minimum 50 x 50mm).
ARDEX WPM188 Bituminous sheet membrane
Prime all prepared substrates with ARDEX WPM240
Bituminous primer and let dry.
Membrane Installation - torch on membrane
Apply the sheet membrane to the prepared substrates using
LPG or LNG torch techniques with sheet overlaps (75mm side-laps and 100mm
end-laps) fully welded together
Begin application from the lowest points of the structure
and work upwards to the highest points.
Once the bituminous sheet membrane has been applied, the
top (free) edge terminations shall be secured by one of the following systems
ARDEX Pressure Seal mechanically fixed into position
Liquid applied flashing such as the ARDEX WPM179
Protection The bituminous sheet membrane is to be
protected from sunlight and mechanical damage by covering with suitable
protective materials such as;
ARDEX Protection Board prior to backfilling
5mm Geotextile fabric prior to backfilling
Double layer plastic (250 - 300 micron thickness
each layer with the top layer laid at right angles to the bottom layer) slip
sheet prior to placement of a self-supporting screed at a minimum 40mm