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 Page 1


Damp Proof and Fire Proof Construction                        
  
 
CHAPTER 14 
DAMP PROOF AND FIRE PROOF CONSTRUCTION 
Damp prevention and fire protection are the chief requirements to 
ensure the safety of buildings against dampness and fire respectively. 
The sources, effects, techniques and methods of damp prevention, 
materials used for damp-proofing (D.P.C) damp-proofing treatments in 
buildings, treatment of dampness are discussed under damp proof 
chapter. 
14.1 Sources of dampness(causes) 
Dampness in building in generally due to one or more of the 
following causes 
(i) Faulty design of structure 
(ii) Faulty construction or poor workmanship 
(iii) Use of poor materials in construction 
These cause give rise to an easy access to moisture to enter the 
building from different points, such as rising of moisture from 
ground, rain penetration through walls, roofs and floors etc. The 
moisture entering the building from foundation and roofs, travels 
in different directions further under the effects of capillary action 
and gravity respectively. The entry of water and its movements, 
in different parts of the building are positively due to the one or 
more of the causes listed above. 
Page 2


Damp Proof and Fire Proof Construction                        
  
 
CHAPTER 14 
DAMP PROOF AND FIRE PROOF CONSTRUCTION 
Damp prevention and fire protection are the chief requirements to 
ensure the safety of buildings against dampness and fire respectively. 
The sources, effects, techniques and methods of damp prevention, 
materials used for damp-proofing (D.P.C) damp-proofing treatments in 
buildings, treatment of dampness are discussed under damp proof 
chapter. 
14.1 Sources of dampness(causes) 
Dampness in building in generally due to one or more of the 
following causes 
(i) Faulty design of structure 
(ii) Faulty construction or poor workmanship 
(iii) Use of poor materials in construction 
These cause give rise to an easy access to moisture to enter the 
building from different points, such as rising of moisture from 
ground, rain penetration through walls, roofs and floors etc. The 
moisture entering the building from foundation and roofs, travels 
in different directions further under the effects of capillary action 
and gravity respectively. The entry of water and its movements, 
in different parts of the building are positively due to the one or 
more of the causes listed above. 
14.2 Effects of dampness: 
The various effects caused due to dampness in buildings mainly 
results in poor functional performance, ugly appearance and 
structural weakness of the buildings. 
1. A damp building creates unhealthy living and working conditions 
for the occupants 
2. Presence of damp condition causes efflorescence on building 
surfaces which ultimately results in the disintegration of bricks 
stones, tiles etc and hence reduction of strength 
3. It may result in softening and crumbling of plaster 
4. It may cause bleaching and flaking of the paint which results in 
the formation of coloured patches on the wall surfaces and 
ceilings 
5. It may result in the corrosion of metals used in the construction of 
buildings 
6. The materials used as floor coverings such as tiles are damaged 
because they lose adhesion with the floor bases 
7. Timber when in contact with damp condition, gets deteriorated 
due to the effect of warping, buckling and rolling of timber 
8. All the electrical fittings gets deteriorated, causing leakage of 
electric current with the potential danger of a short circuit 
9. Dampness promotes the growth of termites and hence creates 
unhygienic conditions in buildings  
Page 3


Damp Proof and Fire Proof Construction                        
  
 
CHAPTER 14 
DAMP PROOF AND FIRE PROOF CONSTRUCTION 
Damp prevention and fire protection are the chief requirements to 
ensure the safety of buildings against dampness and fire respectively. 
The sources, effects, techniques and methods of damp prevention, 
materials used for damp-proofing (D.P.C) damp-proofing treatments in 
buildings, treatment of dampness are discussed under damp proof 
chapter. 
14.1 Sources of dampness(causes) 
Dampness in building in generally due to one or more of the 
following causes 
(i) Faulty design of structure 
(ii) Faulty construction or poor workmanship 
(iii) Use of poor materials in construction 
These cause give rise to an easy access to moisture to enter the 
building from different points, such as rising of moisture from 
ground, rain penetration through walls, roofs and floors etc. The 
moisture entering the building from foundation and roofs, travels 
in different directions further under the effects of capillary action 
and gravity respectively. The entry of water and its movements, 
in different parts of the building are positively due to the one or 
more of the causes listed above. 
14.2 Effects of dampness: 
The various effects caused due to dampness in buildings mainly 
results in poor functional performance, ugly appearance and 
structural weakness of the buildings. 
1. A damp building creates unhealthy living and working conditions 
for the occupants 
2. Presence of damp condition causes efflorescence on building 
surfaces which ultimately results in the disintegration of bricks 
stones, tiles etc and hence reduction of strength 
3. It may result in softening and crumbling of plaster 
4. It may cause bleaching and flaking of the paint which results in 
the formation of coloured patches on the wall surfaces and 
ceilings 
5. It may result in the corrosion of metals used in the construction of 
buildings 
6. The materials used as floor coverings such as tiles are damaged 
because they lose adhesion with the floor bases 
7. Timber when in contact with damp condition, gets deteriorated 
due to the effect of warping, buckling and rolling of timber 
8. All the electrical fittings gets deteriorated, causing leakage of 
electric current with the potential danger of a short circuit 
9. Dampness promotes the growth of termites and hence creates 
unhygienic conditions in buildings  
Damp Proof and Fire Proof Construction                     
  
10. Dampness when accompanied by the warmth and darkness, 
breeds the germs of tuberculosis, neuralgia, aute and chronis 
neumatism etc which some times result in fatal diseases 
14.3 Techniques and methods of damp prevention: 
The following are the precautions to be taken to prevent 
dampness in buildings, before applying the various techniques. 
1. The  site should be located on high ground and well drained 
soil to safe guard against foundation dampness 
2. All the exposed walls should be of sufficient thickness to 
safeguard against rain protection (minimum 30cm) 
3. Bricks of superior quality free from defects should be used 
4. Good quality cement mortar (1:3) should be used to produce 
definite pattern and perfect bond in the building  
5. Cornices and string courses should be provided to through 
rain water away from the walls 
6. All the exposed surfaces like top of walls, compound walls 
etc should be covered with water proofing cement plaster 
7. Cavity walls are more reliable than solid walls in preventing 
the dampness 
Techniques: 
1. Use of damp proof courses 
2. Water proof or damp proof treatments 
3. Cavity walls or hallow walls 
Page 4


Damp Proof and Fire Proof Construction                        
  
 
CHAPTER 14 
DAMP PROOF AND FIRE PROOF CONSTRUCTION 
Damp prevention and fire protection are the chief requirements to 
ensure the safety of buildings against dampness and fire respectively. 
The sources, effects, techniques and methods of damp prevention, 
materials used for damp-proofing (D.P.C) damp-proofing treatments in 
buildings, treatment of dampness are discussed under damp proof 
chapter. 
14.1 Sources of dampness(causes) 
Dampness in building in generally due to one or more of the 
following causes 
(i) Faulty design of structure 
(ii) Faulty construction or poor workmanship 
(iii) Use of poor materials in construction 
These cause give rise to an easy access to moisture to enter the 
building from different points, such as rising of moisture from 
ground, rain penetration through walls, roofs and floors etc. The 
moisture entering the building from foundation and roofs, travels 
in different directions further under the effects of capillary action 
and gravity respectively. The entry of water and its movements, 
in different parts of the building are positively due to the one or 
more of the causes listed above. 
14.2 Effects of dampness: 
The various effects caused due to dampness in buildings mainly 
results in poor functional performance, ugly appearance and 
structural weakness of the buildings. 
1. A damp building creates unhealthy living and working conditions 
for the occupants 
2. Presence of damp condition causes efflorescence on building 
surfaces which ultimately results in the disintegration of bricks 
stones, tiles etc and hence reduction of strength 
3. It may result in softening and crumbling of plaster 
4. It may cause bleaching and flaking of the paint which results in 
the formation of coloured patches on the wall surfaces and 
ceilings 
5. It may result in the corrosion of metals used in the construction of 
buildings 
6. The materials used as floor coverings such as tiles are damaged 
because they lose adhesion with the floor bases 
7. Timber when in contact with damp condition, gets deteriorated 
due to the effect of warping, buckling and rolling of timber 
8. All the electrical fittings gets deteriorated, causing leakage of 
electric current with the potential danger of a short circuit 
9. Dampness promotes the growth of termites and hence creates 
unhygienic conditions in buildings  
Damp Proof and Fire Proof Construction                     
  
10. Dampness when accompanied by the warmth and darkness, 
breeds the germs of tuberculosis, neuralgia, aute and chronis 
neumatism etc which some times result in fatal diseases 
14.3 Techniques and methods of damp prevention: 
The following are the precautions to be taken to prevent 
dampness in buildings, before applying the various techniques. 
1. The  site should be located on high ground and well drained 
soil to safe guard against foundation dampness 
2. All the exposed walls should be of sufficient thickness to 
safeguard against rain protection (minimum 30cm) 
3. Bricks of superior quality free from defects should be used 
4. Good quality cement mortar (1:3) should be used to produce 
definite pattern and perfect bond in the building  
5. Cornices and string courses should be provided to through 
rain water away from the walls 
6. All the exposed surfaces like top of walls, compound walls 
etc should be covered with water proofing cement plaster 
7. Cavity walls are more reliable than solid walls in preventing 
the dampness 
Techniques: 
1. Use of damp proof courses 
2. Water proof or damp proof treatments 
3. Cavity walls or hallow walls 
4. Guniting or shot concrete or shotcrete 
5. Pressure grouting or cementation 
1. Use of damp-proof courses (D.P.C.) 
These are layers or membranes of water repellent materials such 
as bituminuous felts, mastic asphalt, plastic sheets, cement 
concrete, mortar, metal sheets, stones etc which are interposed in 
the building structure at all locations wherever water entry is 
anticipated or suspected. The best location or position of D.P.C. 
in the case of building without basement lies at plinth level or 
structures without any plinth level, it should be laid at least 15cm 
above ground level. The damp proof course provided horizontally 
and vertically in floors, walls etc. In the case of basements, laying 
of D.P.C. is known as taking Fig 14.1 shows the D.P.C. treatment 
above ground level. 
 
Fig 14.1 D.P.C. above ground level for new buildings 
2. Water proof surface treatments: The surface treatment consists 
in filing up the pores of the material exposed to moisture by 
Page 5


Damp Proof and Fire Proof Construction                        
  
 
CHAPTER 14 
DAMP PROOF AND FIRE PROOF CONSTRUCTION 
Damp prevention and fire protection are the chief requirements to 
ensure the safety of buildings against dampness and fire respectively. 
The sources, effects, techniques and methods of damp prevention, 
materials used for damp-proofing (D.P.C) damp-proofing treatments in 
buildings, treatment of dampness are discussed under damp proof 
chapter. 
14.1 Sources of dampness(causes) 
Dampness in building in generally due to one or more of the 
following causes 
(i) Faulty design of structure 
(ii) Faulty construction or poor workmanship 
(iii) Use of poor materials in construction 
These cause give rise to an easy access to moisture to enter the 
building from different points, such as rising of moisture from 
ground, rain penetration through walls, roofs and floors etc. The 
moisture entering the building from foundation and roofs, travels 
in different directions further under the effects of capillary action 
and gravity respectively. The entry of water and its movements, 
in different parts of the building are positively due to the one or 
more of the causes listed above. 
14.2 Effects of dampness: 
The various effects caused due to dampness in buildings mainly 
results in poor functional performance, ugly appearance and 
structural weakness of the buildings. 
1. A damp building creates unhealthy living and working conditions 
for the occupants 
2. Presence of damp condition causes efflorescence on building 
surfaces which ultimately results in the disintegration of bricks 
stones, tiles etc and hence reduction of strength 
3. It may result in softening and crumbling of plaster 
4. It may cause bleaching and flaking of the paint which results in 
the formation of coloured patches on the wall surfaces and 
ceilings 
5. It may result in the corrosion of metals used in the construction of 
buildings 
6. The materials used as floor coverings such as tiles are damaged 
because they lose adhesion with the floor bases 
7. Timber when in contact with damp condition, gets deteriorated 
due to the effect of warping, buckling and rolling of timber 
8. All the electrical fittings gets deteriorated, causing leakage of 
electric current with the potential danger of a short circuit 
9. Dampness promotes the growth of termites and hence creates 
unhygienic conditions in buildings  
Damp Proof and Fire Proof Construction                     
  
10. Dampness when accompanied by the warmth and darkness, 
breeds the germs of tuberculosis, neuralgia, aute and chronis 
neumatism etc which some times result in fatal diseases 
14.3 Techniques and methods of damp prevention: 
The following are the precautions to be taken to prevent 
dampness in buildings, before applying the various techniques. 
1. The  site should be located on high ground and well drained 
soil to safe guard against foundation dampness 
2. All the exposed walls should be of sufficient thickness to 
safeguard against rain protection (minimum 30cm) 
3. Bricks of superior quality free from defects should be used 
4. Good quality cement mortar (1:3) should be used to produce 
definite pattern and perfect bond in the building  
5. Cornices and string courses should be provided to through 
rain water away from the walls 
6. All the exposed surfaces like top of walls, compound walls 
etc should be covered with water proofing cement plaster 
7. Cavity walls are more reliable than solid walls in preventing 
the dampness 
Techniques: 
1. Use of damp proof courses 
2. Water proof or damp proof treatments 
3. Cavity walls or hallow walls 
4. Guniting or shot concrete or shotcrete 
5. Pressure grouting or cementation 
1. Use of damp-proof courses (D.P.C.) 
These are layers or membranes of water repellent materials such 
as bituminuous felts, mastic asphalt, plastic sheets, cement 
concrete, mortar, metal sheets, stones etc which are interposed in 
the building structure at all locations wherever water entry is 
anticipated or suspected. The best location or position of D.P.C. 
in the case of building without basement lies at plinth level or 
structures without any plinth level, it should be laid at least 15cm 
above ground level. The damp proof course provided horizontally 
and vertically in floors, walls etc. In the case of basements, laying 
of D.P.C. is known as taking Fig 14.1 shows the D.P.C. treatment 
above ground level. 
 
Fig 14.1 D.P.C. above ground level for new buildings 
2. Water proof surface treatments: The surface treatment consists 
in filing up the pores of the material exposed to moisture by 
Damp Proof and Fire Proof Construction                         
  
providing a thin film of water repellent material over the surface 
(internal / external ) . External treatment is effective in preventing 
dampness 
Many surface treatments, like pointing, plastering, painting, 
distempering etc are given to the exposed surfaces and also to the 
internal surface . The most commonly used treatment to protect 
the walls against dampness is lime cement plaster (1:6) (1-
cement, 6-lime) mix proportion. Generally employed as water 
proofing agent in surface treatments are sodium or potassium 
silicate. Aluminium or zinc sulphate, Barium Hydroxide and 
magnesium sulphate in alternate applications. Soft soap and alum 
also in alternate applications, unie and unseed oil; coal tar, 
bitumen, waxes and fats; resins and gums 
Waxes and fats are not suitable in tropics as they melt with 
rise in temperatures 
3. Integral damp-proofing treatments : 
The integral treatment consists of adding certain compounds to 
the concrete or mortar during the process of mixing, which when 
used in construction acts as barriers to moisture penetration under 
different principles 
i) Compounds like chalk, talc, fallers earth etc have 
mechanical action principle (i.e.,) they fill the pores 
present in the concrete or mortar and make them 
dense and water proof