Hollow Walls

A cavity wall consists of two parallel walls or leaves or skins of masonry separated by a continuous air space or cavity. The walls of the cavity consist of three main parts, namely,

Outer wall or leaf (10 cm thick) which is the outer part of the wall.
A cavity or air space of 5-8 cm.
Inner wall or leaf (minimum 10 cm) that is the inner part of the wall.
The two leaves, which form the cavity in the middle, may be of equal thickness or the thickness of the inner leaf may be increased to take a greater proportion of the load transferred by the floor and roof. The provision of a continuous cavity in the wall effectively prevents moisture transmission or percolation from the outer wall or leaf to the inner wall or leaf. Based on the climatic conditions in India, i.e. hot dry (hot humid), this cavity type of construction is most desirable as it offers many advantages such as better living and comfort conditions, construction economy and moisture proof building. Protection of

Cavity wall construction offers the following advantages over solid wall construction:

Since there is no contact between the outer and inner walls of the cavity wall except for the wall joints, which are made of poor material, the possibility of moisture ingress is minimized. It has been established that a cavity wall with 10 cm thick inner and outer leaves is better and more reliable than a 20 cm thick solid wall with a 5 cm cavity or air space in between, in terms of wet penetration.
Because cavity air is a thermal insulator, it prevents heat conduction through the walls and maintains better temperature consistency within the building. In this regard, it has been established that cavity walls provide a 25% improvement in thermal insulation over solid walls of the same cross-section less the cavity thickness. Hence, cavity wall construction is ideal for a tropical country like India.
The cavity walls also offer good insulation against sound.
Cavity reduces flower disturbance.
This type of construction also offers many other advantages such as economy, better comfort and hygienic conditions in buildings.