PCS WATERPROOFING INSTRUCTIONS
ONLY FOR USE WITH PCS THERMAL SUBSTRATE BOARDS.
PCS Waterproof Jointing and Tanking System has been developed to provide a watertight sealing system for use in
environments such as wet rooms, shower cubicles, swimming pools, spa centres and other applications subject to high levels of
water contact.
The PCS waterproof system is based on co polymer technology and is easy to use. The instructions set out below will ensure a
watertight system. The joints between boards are sealed using a two part adhesive / sealant system that is reinforced with a
100mm wide Alkaline Resistant Jointing Tape.
Step 1
Preparation
Ensure that all traces of dust, and grease contamination are removed.
Ensure that all boards have been cut accurately and that there are no gaps or holes larger than 4mm, Should there be damage
to the board edges they must be repaired prior to commencing the waterproofing process. Boards can be repaired by filling gaps
with a cement based tile adhesive or a suitable sealant.
All Corner joints including wall and floor must be sealed using a good proprietary waterproof sealant prior to applying the Alkaline
Resistant Mesh and waterproofing Tanking compound.
Ensure that the sealant bead is forced down into all joints paying attention to corners ensuring a continuous solid bead is
maintained.
Allow the sealant to dry before applying the flexible cementitious waterproofing system.
Step 2
Taping joints with Alkaline Resistant Mesh (see reverse side)
Apply self adhesive tape over all joints prior to applying Tanking compound. All joints must be bridged with the tape
At corner position where the base meet the walls, it is recommended that the tape is cut 50mm to centre allowing the tape to be
folded promoting a neat 90° bend. If the mesh is cut short another piece can be added but must overlay the existing mesh by
50mm
Step 3
Mixing Waterproof Tanking Compound
The cementitious membrane is a two-pack system, PCS Tanking Compound, a dry blended powder, and PCS Tanking Flexible
Additive, a liquid flexible additive.
Only mix the amount required to cover the joints and the board surfaces. To prevent wastage we recommend mixing small
batches rather than mixing too much material.
Coverage
3 kg covers 1m² for a 1mm thick layer
(1m² is equivalent to 6 linear meters at a width of 150mm)
Two layers will normally be required at approx 1mm thick per coat.
Mix Ratio
1 kg dry powder with approximately 220ml of the liquid additive.
Place the liquid flexible additive in a clean container and slowly add the correct amount of powder. Mix with a mechanical whisk
to produce a smooth, lump free paste. DO NOT ADD WATER
Step 4
Application of Tanking Compound
PCS Thermal Substrate Boards are completely waterproof components so it is only necessary to carry out the tanking process
over the joint areas.
ALL JOINTS MUST BE TAPED WITH ALKALINE RESISTANT MESH
Apply a coating of the mixed PCS waterproof compound over the taped joints using a plastering trowel or spatula ensuring good
compaction into corners and joints. The coating should be applied sparingly at approximately 0.5mm to 1mm thick and at least
150mm wide.
Once all joints have been coated and smoothed down allow approx 4 hrs to dry prior to applying a second layer of paste. Drying
time may vary and is dependent entirely on temperature and air flow.
When the first layer of compound is touch dry apply a thin second coating over the joints again between 0.5mm and 1mm thick.
Smooth down when finished ensuring no unsightly lumps or paste build up in corners which could cause problems for tiling at a
later stage.
Once all surfaces are fully cured tiling can begin.
Note All information above is given in good faith, however as we do not have knowledge of specific site conditions and the capability of the
installer, we accept no liability for damage which may arise as a result of poor installation.
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