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BALCONIES, TERRACES AND ACCESS DECKS

Falls must be provided to balconies and terraces to enable water to flow from the building. In all cases thresholds should be placed 150mm above the horizontal area to enable an asphalt skirting, turned into a chase at the top, to be formed to prevent the ingress of water. Work to handrails, gutters and outlets should be in accordance with details given previously, click here for details.

Where asphalt is required as a paving to be exposed to the weather and subjected to foot traffic, it is laid in two coats. The first coat is laid to a nominal thickness of 10mm in roofing asphalt and the second coat 15mm in the same roofing asphalt incorporating an additional 10% to 15% by weight of 3mm coarse aggregate (Fig. 1.48).

Where point loading is anticipated the surface should be tiled (Fig. 1.49).

Compressible insulation must not be used under Asphalt on balconies and terraces. A protected membrane system with paving slabs forms a suitable specification for insulated balconies. Alternatively Asphalt laid over Cellular Glass or cork/polyurethane composite insulation and protected with promenade surfacing can usually be considered.

BALCONIES AND TERRACES

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ACCESS DECKS AND PODIA

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ROOF GARDENS

Three coat asphalt roofing is an ideal water proofing material for buried systems such as roof gardens.

When designing a roof garden to receive mastic asphalt the following principles should be followed.

  • · Asphalt must be protected from backfilling and subsequent digging operations. This can be achieved with extruded polystyrene insulation boards. Alternatively paving slabs or a non-biodegradable protection board can be used if insulation is not required.
  • · All drainage should be provided at the asphalt water proofing membrane level.
  • · A filter layer will normally be required to prevent blockage of the outlets
  • · Vertical areas of asphalt should extend a minimum 150mm above the finished level.
  • · All pedestrian areas should have adequate falls, preferably 1 in 50.
  • · On all horizontal areas left unburied the asphalt should be suitably protected by promenade tiles or paving slabs.