Category: Protection of Buildings

With reference to fire, materials may be classified as combustible materials and non-combustible materials. Combustible materials are the materials which combine exothermally with oxygen and give rise to flame at a particular range of temperature. Examples of such materials are wood, wooden products, animal products, and man-made products like fibreboard, strawboard, etc. Non-combustible materials are…

When some materials get ignited, the material catches fire and spreads. If there are opening in walls and floors the fire spreads to more area. If there are no openings, the temperature of the structure is increased by fire. In buildings, staircases and lift shaft act as flues for fire and increases the possibility of…

In this process certain compounds are added along with concrete or mortar while mixing which when used in construction act as barriers to moisture penetration. The added materials function based on different principles. Based on the mechanical principle, materials like chalk, talk, fullers earth, etc., fill in the pores present in the concrete or mortar…

In this method the surface exposed to moisture is treated by providing a thin film of water-repellent material over the surface. Such a surface treatment may be external or internal. Generally the external treatment is more effective in damp prevention when compared to internal treatment. Surface treatments include pointing, plastering, painting, distempering, etc., Lime-cement plaster…

Materials generally used for DPC are flexible materials like, hot bitumen, bituminous felts, bituminous sheets, polythene sheets, metal sheets of lead, copper, etc.; semi-rigid materials like mastic asphalt or combination of materials or layers and rigid materials like first-class bricks, stones, slates in courses and cement-concrete stones, slates in courses and cement-concrete or mortar layers, etc.

Provision of damp proof course at plinth level is shown in Fig. 29.2, whereas Fig. 29.3 shows the DPC in basement. Figure 29.2 DPC above ground level Figure 29.3 DPC in basement Prevention of damp along parapet walls and flat roof are shown in Figs. 29.4 and 29.5. Figure 29.4 DPC in parapet wall Figure 29.5 DPC in flat roof

Damp-proofing courses (DPC) of suitable materials are provided at appropriate locations for their effective use (Sharma, 1988). DPC prevents basically the entry of the water from ground in buildings. The best position for DPC is the plinth level in buildings. Following general principles should be adopted while providing DPC in buildings:

In general, presence of dampness results in poor functional performance, shabby appearance and structural weakness. Following are the effects of dampness:

Dampness in a building may be caused due to natural causes or structural causes. 1. Natural Causes Natural causes may be due to: (i) Penetration of Rain Rain may penetrate a building through the top of the walls, through the surface of the walls and through the roof. Rain may penetrate the unprotected parapet walls…

Presence of hydroscopic moisture on a surface is called dampness. In general dampness causes unhygienic conditions, affects the health and comfort of inhabitants. Further, it deteriorates the stability of the damped surface. Thus, it is an essential feature in construction to prevent dampness.