Introduction to Damp Proofing

Damp Proofing



Type DPC Profiles - Raft Construction / Ground Beam

Use

To provide perimeter DPC when constructing using raft foundations or where the cavity does not continue below DPC level.


Solution

DPC Profiles for raft foundation construction are manufactured from accurately dimensioned semi-rigid shaped Petheleyne. They are bedded and lapped on the foundation prior to the commencement of masonry being laid.
Unlike roll material, the DPC profile cannot not sag or distort and fulfils the requirements of NHBC 4.5 D12 –D13. The cranked DPC profile is manufactured in a range of heights corresponding with masonry course heights.
Because there is no continuation of cavity by virtue of the concrete raft, water is drained out of the structure using caviweeps appropriately positioned in perp joints around the structure at
DPC level.

• One-piece DPC wall protection
• Matches raft edge dimensions
• Integrates with oversite membrane
• Establishes gas protection provision


The inboard section of the DPC extends 150mm minimum beyond the inside face of the internal skin to facilitate positive lapping and integration with any oversite membrane. (recommended)
Raft cavity walls should drain below DPC and prevent water flooding cavities above DPC levels or crossing from the outside to the inside. A clear cavity descending 225mm below the inner skin/raft DPC level is required.
Where foundations other than strip or trench fill are used, including those for timber framed dwellings, this may be reduced to 150mm
minimum below DPC provided that weep holes and other measures where necessary, are taken to ensure that the cavity can drain.