GEOSYNTHETICS

Structural Drainage II

Block Paving Drainage

Finesse Deckdrain is a drainage composite with a specially developed structure and physical properties for use in block paving. It has hydraulic properties designed for reliable and sustainable performance. The mechanical resistance is sufficient to endure installation and long term loading. Its function is to collect and remove seepage water from the sand course below block paving.

The importance of removing this water and preventing saturation of the sand is especially critical where there is traffic loading and the foundation layer is relatively impermeable (e.g. concrete, asphalt, roof decks etc.). For the sand course (30-50 mm thick) to provide adequate support to the blocks it must be

relatively dry (i.e. optimum moisture content). If the sand becomes almost totally saturated with seepage water, the traffic load will cause the sand to liquefy and pump up through the joints. This condition is easily identified on existing sites by surface staining and open joints. In severe cases the blocks will be loose and uneven. The solution is to provide Finesse Deckdrain below the sand to prevent the sand becoming saturated. Deckdrain also provides protection against puncture where a waterproofing membrane is required below the block paving (e.g. roof top car parks).

Roof Gardens
Deckdrain offers an effective and reliable drainage system for roof gardens of all sizes. A suitable depth of soil is placed directly onto the Deckdrain. The high CBR puncture resistance of Deckdrain protects the waterproofing from backfilling forces and root penetration.

Lost Shuttering
Deckdrain as a lost shuttering is installed with the flat face of the core towards the concrete and the geotextile side against the existing soil. Poured concrete fills the dimples and Deckdrain becomes an integral part of the new structure. Deckdrain performs as a ground water drainage system and provides a high level of protection to the new structure.

Tunnels
The use of Deckdrain in tunnel lining provides an economic and effective drainage system. The geotextile side of the Deckdrain is installed against the shotcrete on the rock face and the flat side of the core against the tunnel lining. Deckdrain will collect and drain the seepage water to the perforated pipes at the base of the rock walls.

Playing Fields and Landscaping
Deckdrain is used conveniently to replace horizontal granular layers in sport turf drainage and landscaping applications. Deckdrain reduces excavation and backfill and provides efficient drainage and separation.