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PLATON DOUBLE DRAIN MEMBRANE APPLICATION
(for external applications only)

The material can be fitted either vertically or horizontally and therefore would depend on the size of the job as to which option is chosen. It is considered far more economical to fit the product horizontally.

	WALL PREPARATION (top)
	The wall surfaces must be clean and free from cavities, protruding sharp objects. Where protruding ribs or foundation toes occur, a concrete/sand & cement filler piece should be cast/formed to prevent water gathering or laying against the foundation slab.
	Apply a bitumen primary membrane to the walls and foundation toe, with a minimum of two coats and allowing 24 hours drying time between each coat.

	MEMBRANE INSTALLATION (top)
	Starting at the base of the walls, roll out the Platon double drain horizontally against the wall with the filter fabric outwards and fix the fixing cramps along the top edge only at 250mm centres. The membrane is hung down the walls like a curtain.
	NB if a foundation toe protrudes out from the wall, then the membrane should be extended over the horizontal section of the toe and down the vertical edge.
	Continue fitting the membrane horizontally as described above around all walls. Where the next roll/sheet of membrane is to be joined at the vertical edge, carefully peel back the filter fabric from the membrane to be overlapped by approximately 120mm. Platon sealing rope is then laid in a vertical line within the channel between the first & second stud and the overlapping section of membrane is then pressed stud to stud to form a seal down the vertical joint.
	Once the bottom run of membrane has been fitted horizontally around the walls, the next roll of membrane is also run horizontally in the same manner as mentioned above. However, the top membrane overlaps the bottom membrane at the horizontal joint by 120mm. Again the filter fabric is carefully peeled back from the bottom membrane at the joining edge to allow a stud to stud overlap. No sealing rope at this horizontal joint is necessary, but fixing cramps are required at 250mm centres along the joint.
	The membrane should be terminate 150mm above external ground level and at this point the Platon top edge mould is fixed using masonry nails. At the base of the wall a graded drainage material should be laid incorporating a geo-textile perforated land drainage pipe. The size of this pipe will need to be determined by the project engineer. Once the drainage pipe is in place, it should be water tested before being concealed with graded backfill/drainage material. We recommend that the external ground be finished with a 1 in 50 gradient away from the walls.
	Finally, compaction of back-fill should be conducted with care to avoid damaging the membrane, and direct tipping from lorries should be avoided.

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