Structures Below Ground
The STYROFOAM Solution for externally insulating
basement walls is PERIMATE-DI-A.
Structure below ground must prevent ground water reaching the interior of a building in order to maintain suitable internal conditions (see BS 8102 for gradings). A common way of providing waterproofing is to use externally applied tanking membranes of mastic asphalt or bituminous sheet. In such constructions insulation can be located outside the waterproofing, where it will:
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insulate the structure.
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protect the tanking material from physical damage caused by the rest of the construction process or by the backfill material.
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drain water away from the structure, reducing the hydrostatic pressure on the tanking membrane.
When externally insulating basement walls the insulation boards are laid against the tanking membrane and the excavation is then backfilled (Figure 50). The construction is suitable for new build; it is also suitable for refurbishment projects. For guidance on constructing basements consult the Approved Document: Basements for dwellings.
