Why Plastic Sheet(Polyethene)/Membrane/Vapour barrier laid under the Industrial Concrete Floor?

Slip Membrane( Polyethene)/Vapour Barrier

• It is known as Vapour Barrier/Slip Membrane/ Polyethene- LDPE sheet.
• To reduce the friction between the slab and the sub-base which means concrete slabs can shrink freely due to temperature variation and also reduce the cracks.
• To prevent the loss of mixing water from the concrete down into the subbase or subgrade.
• To reduce bleeding and curling.
• Membranes are normally ( 200 -300 microns) plastic sheets.
• It is important to lay the membrane without creases and that it is overlapped at the edges by at least 200-300mm. 
• Prior to and during concreting, special precautions should be taken to avoid damage to the vapour barrier, and any tears or perforations should be patched immediately.