Building is made of exterior and interior walls. Walls can be
(i) Solid walls.
(ii) Cavity walls - It consists of two walls with a 5cm. to 8cm. cavity between them. The outer wall consists of 10cm. thick and the inner wall is 10cm thick minimum. Rust proof strips of metal are placed in intervals to link the two walls together.
Advantages of Cavity Walls
(a) There is no possibility of the moisture travelling from the outer wall to the inner wall.
(b) The layer of air in the cavity being non-conductor of heat, it reduces the transmission of heat from the external face to internal one. Cavity walls have 25% greater insulating value than solid walls. This acts as damp barrier, reduces the cooling cost of the building.
(c) These have good sound insulation property.
(d) They are economical.
(a) Damp proof course should be laid separately for two walls.
(b) The cavity should be properly drained and ventilated by providing weep holes.
(c) Cavity should be kept clear of dropping of mortar or brick, rubbish etc during construction.
(d) Vermin's or mosquitoes should not be there in the cavity wall.
(iii) Partition Wall - A wall made of bricks, studding glass, wood etc. for the purpose of dividing the one room/portion from another.