Material for dpcs

• Bs 743 gives 7 suitable material for the construction of damp-proof courses , all of which should have the following properties:
• Be completely impervious
• Be durable , having a longer life than the other components in the buildings and therefore not needing replacing during its lifetime
• Be in comparatively thin sheet so as to prevent difigurement of the building
• Be strong enough to support the loads placed upon it without exuding from the wall
• Be flexible enough to give any settlement of the building without fracturing

seven suitable material for the construction of dpcs:

• Lead

-It is a flexible material supplied in thin sheets , and therefore large irregular shapes with few joints can be formed , but it has the disadvantage of being expensive

• Copper

-This should have a minimum thickness of 0.25mm , like lead it is supplied in thin sheets and is expensive .

• Bitumen

-THis is supplied in the form of a felt , usually to brick widths , and is therefore laid quickly with the minimum numbers of joints

Mastic asphalt

-Applied in two layers giving a total thickness of 25mm , it is applied in-situ and is therefore jointless , but is expensive in small quantities

• Polythene

-Black low-density polythene sheet of single thickness not less than 0.5mm thick should be used , it is easily laid but can be torn and puntured easily

• Slates

-These should not be less than 230mm long nor less than 4mm thick and laid in two courses set breaking the joint in cement mortar 1:3

• Slates have limited flexibility but are impervious and very durable

-Bricks

• THey are laid in two courses in cement mortar and may constrast with the general appearance of other brickwork in the same wall