A damp proof course ( dpc ) is a physical barrier inserted into the fabric of a building to stop water passing from one place to another. This can be on a horizontal plane, stopping water rising up from the ground by being sucked up by the dry masonry above, or vertically to stop water passing from the outside of a building, though the masonry, to the inside. Dpc's have taken many forms through the ages and one of the earliest forms was to use a layer of slate in the construction. Slate is still used but the less expensive plastic version ( below right ) is now more widely used.
Technical specification of dpc
Water vapour permeability
0.28 gm2 day-1
Bs3177
Water vapour transmission
733 mnsg-1
Water absorption
0.22%
Bs2782 : 430a
Resistance to leakage at joints
Pass
Moat 27 : 5.2.1
Tensile strength of joint
Unaged : 300 n
Heat aged : 290 n
Water soak : 257 n
Moat 27 : 5.2.2/3/4
Cold flex temperature
−60¡ãc
Bs2782 : 320a
Tensile strength
L : 12.9 nmm-2
T : 11.2 nmm-2
Bs2782 : 320a
Elongation at break
L : 415%
T : 582%
Bs2782 : 320a
Tear strength
L : 122 nmm-1
T : 96 nmm-1
Bba method
Low temperature flexibility
L : <−25
T : <−25
Moat 27 : 5.4.2
Dimensional stability
L : −2.0%
T : −0.3%
Moat 27 : 5.1.6
Mortar adhesion test
Pass
Cream method
Size available
110mm x 30 m/50m
150mm x 30 m/50m
230mm x 30 m/50m
300mm x 30 m/50m
380mm x 30 m/50m
450mm x 30 m/50m
600mm x 30m/50m
Special sizes made to order
Supplier: Self-adhesive bitumen flashing tape, poly dampcourse, bitumen malthoid dampcourse, self adhesive bitumen waterproof membrane, app/sbs modified bitumen waterproofing membrane, torched on waterproofing membrane, bitumen primer, hatch cover sealing tape, non-woven polyester fabric
Self adhesive bitumen flashing tape is a self-adhesive, aluminum /hdpe film surfaced bitumen backed sealing strip. It is a quick, efficient and cost effective method of flashing, sealing and repair that produces a lasting protection in all climates. Self adhesive bitumen flashing tape is a self-adhesive, aluminum surfaced bitumen backed sealing strip. It is a quick, efficient and cost effective method of flashing, sealing and repair that produces a lasting protection in all climates. It is recommended for all substrate sealing repairs on asphalt, bituminous sheets, glass, metal, plastics, timber, mortar, concrete, bricks, roof tiles, stone. Seal guttering, downpipes, roof sheets or flashings. Seal cracked brickwork, concrete, titles or glass. Seal carport or verandah roof to main wall. Seal window frames, chimney, etc Technical information An aluminum foil/ hdpe film carrier A self adhesive rubber modified compound and A silicone coated release interleave( removed during application) Thickness: 1.0mm, 1.2mm, 1.5mm Available in rolls: 50mm x3m, 75mm x 3m, 50mm x 10m, 100mm x 10m, 150mmx10m, 225mm x 10m Special sizes made to order
Malthoid is a 2 ply felt material impregnated with bitumen which is also covered in a fine sand to prevent sticking when rolled. Malthoid is used for waterproofing of flat roofs and under corrugated iron water tanks, to prevent condensation corrosion. Usage: For prevention of rising moisture up through walls of brickwork etc., 90mm x 20mm roll 110mm x 20m roll 150mm x 20m roll 230mm x 20m roll 300 mm x 20m roll 1m x 20m roll 1m x 10m roll Special sizes made to order
