Cavity Wall

A cavity wall consists of two walls along with a cavity of 5 to 8 cm among them. The outer wall consists of a 100 mm thick wall and the inner wall is satisfactorily thick and strong to carry the imposed loads safely. The minimum thickness of the inner wall is restricted to 100 mm.

A cavity wall has the subsequent advantages:

(a)        The provision of a continuous cavity within the wall efficiently avoids the transmission of dampness to the inner wall.

(b)       Cavity walls have good sound insulation property.

(c)        Construction of cavity walls is economical.

(d)       There is no option of the moisture travelling from the outer leaf to the inner leaf since there is no intimate contact among the two leaves except at the wall ties.

(e)        Cavity walls have 25 percent greater insulating value than solid walls.

(f)        Cavity walls are best appropriate for a tropical country.

The subsequent points should be kept in mind during construction of a cavity wall:

(a)        The contact among the inner and outer wall should be avoided.

(b)       During construction, essential precautions are needed to be taken so in which no mortar or any other thing should get accumulated within the cavity.

(c)        The horizontal damp proof course should be built in two separate widths under each leaf of the wall and divided through cavity.

(d)       The cavity should be free from some projections.

(e)        The heads of openings should be carefully attended for damp avoids while doors and windows are given in the wall.

(f)        Ties should be able to avoid transmission of water from inner face to the outer face and it must be of rust proof material.