Components, systems and materials › Building components › Damp-proof course
Damp-proof course
What it is
A damp-proof course (DPC) is a continuous impervious layer laid in walls at plinth level to stop ground moisture rising into the masonry above.
Where it is used
Load-bearing and infill walls in all buildings, at plinth level and below window sills or parapets where needed.
How it works
Masonry and plaster draw water upward by capillary action. A layer with no capillary pores breaks that path, so the walls above stay dry and paint and plaster do not peel.
Types
- Cement concrete DPC with waterproofing admixture
- bitumen or bituminous felt
- polymer membranes
- chemical injection DPC for existing walls
Materials
Cement concrete with integral waterproofing compound, bitumen, polymer sheets.
The DPC must be continuous across the full wall thickness and joined at corners and with any floor membrane. It sits above finished ground level and above splash height.
Installation and QA steps
- Level the top of the plinth masonry
- Lay the DPC concrete or membrane in one continuous run
- Lap and seal joints
- Cure
- Protect until the wall above is built
- Gaps at junctions
- DPC below outside ground level
- Plaster bridging over the DPC
Codes cited
- National Building Code of India 2016 (India): Model code for buildings: planning, structural design, fire, construction practice and safety, building services.
Cited by number only. We do not reproduce code text, tables or figures.
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