Moisture barrier these are material used to prevent the entrance of moisture into a building from the outside or from earth below.

Moisture barrier system will limit water infiltration into unwanted area and allow drainage and drying of wetted building material . Prevents the penetration to the interior of liquid water from from exterior source and drain it from the wall cavity to the outside.

Material used for barrier system

1. Polyethylene film
2. Asphalt coated Kraft paper
3. Wax coated craft paper
4. Aluminium metal foil sheet
5. Paint coating

1. Polyethylene film

It is chemically inert plastic , unaffected by acid,alkalies, produced by rolls. The film may be applied vertically in strip to stud wall,or sheets wide enough to cover the wall from top to bottom

2. Asphalt coated Kraft paper

Used a vapour barrier in several form . one is the foil at single sheet. Another is a thin layer of foil laminated to heavy backing of asphalt impregnated craft paper.