damp prevention in buildings

Refresher Course for SAG officers ( Session No. 837 ) Name of Topic : WATER PROOFING & DAMP PREVENTION IN BUILDINGS Presented on 23.10.2008 BY

J.K. Singla CGE/SEC Rly, Bilaspur

Course Director : Shri S. K . Garg

Guide : Shri Manoj Arora

Name of Topic : WATER PROOFING & DAMP PREVENTION IN BUILDINGS � Neither humans nor buildings can tolerate too little or too much of water. � Excess water in buildings is called Dampness. The root of all evil is water.

� It dissolves buildings.

� It consumes wood, erodes masonry, corrodes metals, peels paint, expands destructively on

freezing, permeates everywhere on evaporation, stinks. � creates unhealthy conditions for residents, cause of growth of fungi, Bacteria, Mites & other

micro organisms. � Dampness is a catalyst for building defects like Corrosion of metals, efflorescence of brick &

mortar, Damage of Masonry & concrete.

� Unwanted moisture can adversely affect their use. � Dampness causes aesthetic as well as physical damage to buildings. It can disfigure internal

wall & ceiling finishes & external wall surfaces 1. Sources of Leakages or Dampness in Buildings

1.1 External Sources of Leakages 1,1.1 Leakages from Roofs :-

(i) Faulty Roof Slopes (ii) Absence of Roof Slab Projection (iii) Junction of Parapet walls & Roof Slab (iv) Inadequate Number & Size of Drainage outlets (v) Spreading of Water on Roofs due to Overflowing from Water Tanks . (vi) Bad Quality of Concrete used in RCC Roof Slab

(vii) Stagnation of water (viii) Poor Quality or Improper Methods adopted in Laying Lime Conc. Terracing or

Mudphuska roofing. 1.1.2 Leakages from External Walls 1.1.3 Dampness due to Leaking Waste Water & Soil Pipes 1.1.4 Faulty Expansion Joints 1.1.5 Chaja Wall Junction 1.1.6 External Cupboards 1.1.7 Balconies

1.2. Internal Sources of Leakages 1.2.1 Faulty Size & Slope of Soil and Waste Pipes 1.2.2 Sunken Floors 1.2.3 Floor Traps 1.2.4 Concealed Water Pipes 1.1.1 Leakages from Roofs ( i) Faulty Roof Slopes

� Leakage has direct relation to the Intensity of Rainfall in the Region & Type of Roof adopted

� Minimum Slope of Roof: 1 in 100

� Recommended Slope: 1 in 40 for Mudphuska Roofing : 1 in 60 for Conc. Roofing

� RCF Colony : Proper s lope towards drainage pipes has not been provided resulting into stagnation of water on the roofs for a longer period which ultimately percolates through cracks or through porous conc slab.

(ii) Absence of Roof Slab Projection

� In absence of s lab projection , the rain water travels along the walls & enters through crack at junction of Roof Slab and Wall (Entry of water mechanism)

� Roof s lab to project beyond wall by 50 mm( minimum) so that water falls clear of the wall (Prevention of water-1)

� All roof projections be provided with a Drip Course to stop back travel of Rain Water. The

size should be minimum 50 mm by 50 mm so as to be effective.

� If it is not possible to extend the roof, the arrangements as shown in (Prevention of water-2) can be adopted.

(iii) Junction of Parapet walls & Roof Slab:-

� Junction of Parapet walls & Roof Slab is a source of leakage & requires to be made water proof.

� To stop leakage, the roof Treatment provided on Roof slab be carried out to the Parapet

Wall through the Junction of Parapet walls & Roof Slab. A chase must be cut in the Parapet Wall at a Height of 20 cm above the roof and the water proofing Treatment should be finished inside the chase (Junction of Parapet walls & Roof Slab )

( iv) Inadequate Number & Size of Drainage outlets

� The number & Size of Drainage outlets be adequate to drain off water without stagnation. Min. size not less than 75mm.

� No. of drain pipes depend upon shape of terrace, location of drainage points & spacing of

drain pipes. 100mm dia pipe can serve an area of 40-50sqm for rainfall intensity of 10 cm per hour.

� The spacing between outlet pipes should not be more than 6m.

� Size of rain water pipes for roof drainage depends on average rate of rainfall in mm/hr &

on the area of roof, as shown in table given below.

� For better drainage effect, Rain Water Pipes having bell mouth inlet at the roof surface be provided.

� Rain water pipes should be secured to the walls/ columns by means of clamps. RWP

should be kept away from walls by using saddle plates as shown in Fig. Dia of pipe Average Rate of Rainfall in mm/Hr. ( Roof area in sqm )

50 75 100 125 150 200

50 13.4 8.7 6.6 5.3 4.4 3.3

65 24.1 16.0 12.0 9.6 8.0 6.0

75 40.8 27.0 20.4 16.3 13.6 10.2

100 85.4 57.0 42.7 34.2 28.5 21.3

125 - - 80.5 64.3 53.5 40

150 - - - - 83.6 62.7

(v) Spreading of Water on Roofs due to Overflowing from Water Tanks :-

� This may happen due to missing of Float Valves . � Defective or broken float valves.

� In RCF Colony , it is seen that defective Float Valves were not replaced with result

overflowing of water tanks.

� No over flow pipes were provided in newly constructed quarters. Action Plan

� All missing or defective float valves were replaced with good quality Float Valves in a time bound manner.

� Instructions issued to connect over flow pipes with Rain Water Pipes to stop splashing of

water on roofs (water tank on roof). (vi) Bad Quality of Concrete used in RCC Roof Slab:-

� Most of leakages can be eliminated if the quality of conc. of Roof Slab is ensured. � A well compacted & cured roof slab is itself Water Proof.

� Close supervision at the time of construction can eliminate leakages due to faulty construction.

� RCC Roof Slabs exposed to Sun lead to large number of hair cracks. These hair cracks

are the sources of leakages. Hence Water Treatment is a must for every roof s lab to prevent leakages.

(vii) Stagnation of water

� Stagnation at the outlets is either due to wrong slopes of the roof or due to choking of rain water pipes. Stagnation also takes place due to depressions on the roof or level of inlet RWP being higher than level of Khurra.

� Terrace area is required to be sloped towards the outlets so that water flows freely.

� Rain water outlet pipes should be provided with gratings at the mouth & they should be

regularly cleaned along with cleaning of roof to prevent from chocking.

� Rain water pipes should be secured to the walls/ columns by means of clamps. (viii) Poor Quality or Improper Methods adopted in Laying Lime Conc. Terracing or

Mudphuska roofing Etc. (Fig) a. The main reasons are:-

� Non availability of skilled labor.

� Cumbersome procedure.

� Time consuming.

� High labor cost.

� Inexperienced contractors & supervisors.

� Unworkable Rates.

b. Steps for Mudphuska Roofing

� Clean the roof. Apply Kerosene oil (Bitumen Primer).

� Apply Bitumen. Sprinkle coarse sand over Bitumen.

� Put mud mortar mixed with Bhusa in slope. Allow it to crack for some days.

� Prepare Gobri leaping( Mix of clay+ cowdung or horsedund). Allow it to decay for one week before use.

� Apply Gobri for filling cracks. .Put Gobri leaping for brick tiling.

� Put brick tiles over Gobri leaping. Leave it undisturbed for a week. No body should walk

over it.

� Grout the tiles joints in cement mortar 1: 3( 1cement + 3 fine sand ).

� Do pointing over brick tiles in cement mortar 1: 3. Do curing.

� Average thickness is 10 cm.

� Mudphuska treatment is for thermal insulation of roof & not for water proofing. For water

proofing Bitumen coating below is applied. 1.1.2 Leakages from External Walls Reasons:-

� Loosely filled brick joint

� Use of poor quality Bricks .

� Improper Curing,poor Workmanship.

� hairline cracks on surface. (MOVIE). Remedy :-

� Use of good quality bricks with joints properly filled up, use of 15mm thick plaster in 1:6.

� Where quality of bricks is poor, use cement mortar 1:4 in two layers.

� Use coarse sand in external plaster .

1.1.3 Dampness due to Leaking Waste Water & Soil Pipes Reasons:-

� Cracks in pipes, Leaking Joints, Improper fixing of cleaning eye.

� Improper grouting of the openings around the pipes in the external walls (MOVIE). Remedy :-

� The inspection of pipes for s igns of cracks before fixing.

� A rubber gasket to be used for fixing the cleaning eye.

� Openings around the pipes in walls be filled up with PCC 1:3:6. . � Plumbing services be planned in such a way that can be maintained easily.

� Service shafts to have sufficient rooms to enable repair teams to work with ease.

1.1.4 Faulty Expansion Joints Reasons:-

� Non monolithic casting of roof slab & parapet wall of expansion gap creating joint at junction.

� Faulty s lope of roofs towards expansion gaps & improper casting of roof s lab on the

joint .

Remedy :-

� Monolithic casting of roof s lab & parapet wall with minimum reinforcement to avoid breaking (fig 1, 2,3 & 4 ).

� Filling of joint between slabs with sealant to seal the joint.

� Provis ion of s loping precast s lab with drip course & water proofing treatment.

1.1.5 Chhaja Wall Junction Reasons:-

� A possible source of dampness in a building is the junction between the wall & chajja .This is due to wrong slope of chajja.This dampness leads to growth of Fungus at the chajja wall junction.

� In RCF colony, residents have kept wood on chajja & have constructed unauthorized

sheds which has prevented free flow of water.

Remedy :-

� Chajja should be given a slope of 1 in 30 with a drip course at the end so that water may not travel back ( Fig 1 & 2).

� All chajjas at junction with wall be provided with gola for effective drainage.

1.1.6 External Cupboards Reasons:-

� Provis ion of half brick thick walls in cupboards in the outer walls. � Use of poor quality bricks in external walls.

� Provis ion of one layer of plastering of 12 mm thickness without water proofing

compounds.

Remedy :-

� In heavy rainfall Regions, don’t provide cupboards in external walls. � External cupboards wherever provided be made water proof from the top & the s ides.

� On the top of the cupboard, a roof projection at a s lope of 1 in 40 with a drip course will

keep rain water away. � Provis ion of good quality of full brick thickness in external cupboards. � 15mm thick plastering in two layers (10+5) with outer layer in 1:4, with water proofing

compound. 1.1.7. Balconies

� Balconies should be given a slope of 1 in 100 so that rain water is drained out.

� The minimum size of the outlets should not be less than 50mm dia.

� Step of 20 mm at the junction of Balcony with room be provided to stop back traveling of rain water.

� All outlets be planned in such a way so as to connect them with Rain Water Pipes

1.2. Internal Sources of Leakages 1.2.1 Faulty Size & Slope of Soil and Waste Pipes

� For adequate movement of waste water it is necessary to provide adequately sized pipes laid to a good slope.

� Size of the pipes must be properly designed based on the peak flows of spent waste

water to be received in different parts. � The flow to be received at any point in the system depends on the number & type of

appliances connected to the system. � Branch drains within the toilets are laid to s lope of about 1:10 to 1: 50. Capacity of these

lines to carry flow depends on the s lope. � NBC prescribes 100 dia for soil s tacks & 75 mm dia for waste stacks with capacity of

500 & 60 fixture units respectively.

1.2.2 Sunken Floors

� Floors in bathrooms, kitchens & toilets are sunk to accommodate floor traps, waste pipes & bends connecting the sanitary appliances & waste pipes. A potential source of seepage is the filling in sunken floors.

� The present practice of use of cinder as filling should be avoided as cinder is a major

culprit in holding the seepage water.

� Lime concrete fillers & lean concrete (PCC- 1:5:10) fillers in some cases have given

better results. � The sunken floor slabs & sides are to be plastered in cement mortar 1:4. Besides they

should be provided with water proofing treatment. � In spite of best of the precautions, occasionally water leaks in sunken floors.

� To provide relief 40 mm dia GI pipes can be provided in the outer wall of sunken floor to

draw away the seeped water (Fig 1 & 2).

1.2.3 Floor Traps

� For preventing passage of foul gas, traps with water seal are invariably used at every fixture.

� Floors in bath rooms, kitchen. � For effective drainage, the slope should not be less than 1 in 100. � Junction of the trap and the waste pipe which is embedded in the floor is a possible

source of leakages. � The joints should be thoroughly tested for leakages before doing the flooring (Figs).

1.2.4 Concealed Water Pipes

� A concealed water pipe is a possible source of leakage. � All concealed water pipes must be thoroughly pressure tested for leakages before

taking up the finishes.

2.0 Recent Techniques

It has already been discussed about the Limitations of the Conventional methods. The need of the hour is to go for recent techniques as discussed below;-

2.1 ̀ Guniting

This is also one of the conventional systems. Consists of depositing an impervious layer of rich cement mortar over the surface to be waterproofed & is carried out by using a special gun.

2.2 Grouting

� This technique is essentially used to reduce the porosity or permeability of concrete as a 1st step towards Waterproofing.

� High fluid materials known as grouts are injected into the body of conc. Under pressure,

such as cement grouts, polymer modified cementitious grouts, epoxies etc. This is not a complete system & needs further treatment like coating.

2.3 Bitumen & Bituminous materials are still considered as very effective systems for Waterproofing. These are used either as hot applied or cold applied.

The main advantages of these systems are :-

� Low cost, Cheap Labor, Easy application. � The main advantages are :- � Black color, Fast degradation under exposed conditions & UV’ Low resistance to high

differentials of temp. 2.4 Integral Waterproofing Compounds

� Used to reduce the water absorption & the porosity/permeability. Also increase cohesion & surface finish. Basically they are Permeability reducers, Water repellents or Polymer modifiers.

2.5 Sealants

� Used to seal the joints provided. The main advantages of these systems are :- � Low cost, Cheap Labor, Easy application in structures like expansion, construction etc. � New generation sealants are based on polysulphides, polyurethane, s ilicons, & new

generation s ingle part Sylyl terminated polyethers. � These are required to provide a seal against ingress or seepage in addition to other

properties like movement accommodation etc. 3.0 New Generation Materials for Waterproofing 3.1 Polymer Modified Cementitious Membranes

� Water soluble polymer in conjunction with cement makes good water proofing systems.

� They have good adhesion with substrate, low water permeability, and compatibility with host concrete.

� They have very good bond with concrete surfaces and are breathable systems.

� In addition these systems are fairly flexible and can bridge small cracks .

3.2 Silicone coatings

� These are colorless water repellent solutions, which are mainly used to protect masonry structures.

� These coatings are mainly used as damp proofing masonry and concrete structures.

� The advantages of these coatings are:- Low cost, Easy and fast rate of application, can

be applied to a wide verity of sub states (masonry, tiles, concrete etc). � The disadvantages of these coatings are:- poor crack bridging characteristics &

incapable of withstanding hydrostatic pressure. Silicon based coatings are classified into:-

� Silicones (Silicon resins, silanes & siliconates). � Silicates (alkaline s ilicates, dialkyl s ilicates etc).

3.3 Torch applied Bituminous Membranes

� Consists of a bituminous primer overlaid with an Actactic polyptopylene (APP). � Or a Styrene butadiene Styrene ( SBS) based membrane which is stuck to the surface

by torching.

� These systems are more ideal for basements & foundations Advantages:-

� High Strength reinforcement gives excellent resistance to Puncture & stress, Bonds well to the substrate & readily formed to contours.

3.4 Crystalline Capillary Waterproofing Systems

� These systems compose of Portland Cement, quartz aggregates & special chemicals, which in the presence of moisture , chemical react with free lime to produce insoluble crystals.

� This crystalline growth reduces porosity by blocking capillaries & filling hairline, non

structural cracks ( upto 0.25 mm) caused by shrinkage or expansion. � Membrane waterproofing system form a surface barrier but these systems in presence

of water continue to produce crystals & a lasting impervious to water. � Advantages: Penetrates concrete, seals capillary tracts, and contains no chloride,

Single part system hence easy application. � Resists chemical attack of sewage & industrial wastes. � Suitable for external & internal applications, Resists negative water pressure.

3.5 Epoxy and Polyurethane Coating

� Epoxy based coatings are mostly used for waterproofing & damp proofing for internal applications. Advantages are: Good Adhesion with different substrates, High chemical resistance & excellent impermeability but limited resistance to UV & High cost.

� Polyurethane coatings offer all the advantage of Epoxy based coatings including good UV resistance.

3.6 Polymer Based Spray- applied Membranes

� These are high performance products designed for a range of application including basements, roofing, tunnels, Water tanks, pile tops, Terraces, underground structures etc.

� The advantages are:- High Bond strength & puncture resistance. � Seamless, high elongation flexibility & high tensile strengths, Crack bridging capacity,

Withstands negative pressure, extremely fast rate of application. � Sets instantly on application & can be applied over green conc and can be applied on

any substrate and to various profiles like shells, folded plates etc. 4.0 New Generation Waterproofing Systems 4.1 Polyurea

� Polyurea applied membrane coatings have the combined advantage of both Epoxy & Polyurethane systems. This system differs from normal Epoxy & Polyurethane in chemical composition & superior performance.

� The advantages are:-Most ideal for waterproofing applications, Seamless, resilient,

excellent chemical resistance, thermal shock and puncture. � Environment friendly. � Curing rate ranging from 30 sec to a few minutes. � Extremely good thermal stability.

5.0 CASE STUDIES – 1( Polymer based Spray Applied Membrane) 5.1 Location: Bhubaneshwar, Contractor: L & T and Product: Proofex SM

Customer Requirement:-The canteen and recreation block of Infosys, Konark consisted of 5 buildings with shell roof. The building had a unique profile with many joints. A foolproof & reliable waterproofing system, which could follow this profile , flexible enough to accommodate the movement of joints, was the requirement. It was time bound & to be completed very fast.

Proposed solution :-Proofex SM- A polymer based spray applied system of Fosroc Chemicals India Pvt Ltd was proposed owing to its superior technical features & incredibly fast rate of application over difficult profiles.

Execution:- After proper surface preparation, Proofex SM membrane was applied using the custom designed spray equipment. The sprayed membrane was immediately covered with a layer of geotextile. The laps in the geotextile were sprayed again with Proofex SM. The entire treated surface was covered with a 100mm thick concrete screed. To prevent cracks on screed,

Polypropylene fibres (supplied by Fosroc) were added to the concrete at a dosage of 150gm per bag of cement.

5.2 CASE HISTORY : 2 (silicon based water Repellent Coating)

Location: Bangalore, Contractor: Formtek, Products: Nitocote SN522

Customer Requirement:-The fascia of Jawaharlal Nehru planetarium building made of Dholpur stone. Algae and fungal growth spoiled the exteriors & caused stains on the buildings. The requirement was colorless water repellent coating for damp proofing the fascia of the building, which would also be resistant to fungal and algae growth. The natural finish of the stone had to be retained.

Proposed Solution:- Cleaning of the surface with Reebaklens followed by Nitocote SN522 a s ilicone water repellent coating of Fosroc chemicals India Pvt Ltd. The consultants and the client approved the system after observing the trial area treated with the system. The surface was properly cleaned using blower and wire brushed using Reebaklens a cleaning agent. The surface preparation was critical and in certain places Strong cleaning agents were used. Then two coats of Nitocote SN 522, water repellent coating was brush applied.

5.3 CASE HISTORY:3 ( Poly based Cementitious Waterproofing Membrane) Location: Chennai, Contractor: Dual Structurals, Product: Brush bond RFX, Nitobond SBR

Customer Requirement:-Ford constructed two 18m high water tanks each of 25,00,000 liters capacity. When water was filled, it s tarted leaking. Ford was unable to inaugurate their plant. Investigations revealed, construction joints were not treated properly and hence were leaking. It was noticed that concrete showed honey combs in various locations. The clients wanted a fool proof solution.

Proposed Solution:-The concrete surface inside the tank was lightly sand blasted. This revealed that the construction joints and the surface were honeycombed. The construction joint & all honey combed surfaces were treated with Nitobond SBR (A Styrine butadiene rubber bonding agent/ mortar modifier) modified mortar. Pressure grouting was done at all the joints using neat cement s lurry and Conbex 100. Brushbond RFX A Polymer modified cementitious water proofing membrane of Fosroc Chemicals India Pvt Ltd. was applied in two coats on the entire surface and allowed to cure. The entire surface was then plastered with Nitobond SBR modified mortar. When tested the tanks showed no signs of leakage.

5.0 Problems in RCF

Due to persistence problems in RCF, no. of agencies were consulted & finally the agency of Panchkula studied the problems & solutions as suggested by them are as under:-

5.1 Efflorescence Treatment by Pealing of Paint

Firm: Neelam’s Building Protection Systems Ltd., Panchkula

Products : Walcrete:300gm/sqft, High Bond-40 :22.5gm sqft & Stanro IW-4:100gm/bag of cement

Proposed Solution: Remove the existing plaster up to brick level. Making 15 mm grooves in joints. Clean & cure the surface properly.

� Filling grooves by cement sand (1:2) mix with High Bond-40 @ 1Kg/bag of cement. Curing the surface for one day.

� Apply 2 coats of walcrete coating with mixing ratio of 1 part of High Bond-40, 4 part of water by

volume, 11 part of walcrete by volume. Mix it properly.

� Again curing surface for one day.

� Over the Walcrete Coating, laying the plaster with mixing ratio of 1 part of cement 4 part of sand mix with Stanro IW-4 @ 100gm/bag of cement.

6.2 Waterproofing Coating on Cupboard area Products : B Guard Primer: 6-8 sqm /Kg/coat, B Guard Top Coat: 7-8sqm /Kg/coat.

Proposed Solution: Remove the existing loose coating from the surface.

� Clean the surface by brush or other mechanical means.

� Apply 1 coat of B Guard Primer.

� Over that apply 2 coats top coat B Guard. 6.3 Bath Room/ Kitchen/ Floor Traps Bonding by High Bond-40 Products: High Bond-40 ( Consumption depend upon the Size of Floor traps ).

Proposed Solution :Clean the floor traps with Acid Water.

� Again wash the floor traps.

� Apply High Bond-40 mix with white cement all around the floor Traps. � High Bond-40 provides excellent bond to conc., masonry, stonework, plaster etc. Before

application of High Bond-40, the surface must be clean, sound and free from loose particles, dust, oil & grease. Before use, it should be slightly damp

6.4 Treatment of Roof Khurra by BPG 700 & B. Guard

� Remove the existing khurra upto RCC roof level.

� Clean the surface thoroughly.

� Sealing of all pipe joints by BPG-700/Crackseal RTV.

� After that, apply one coat of Primer B. Guard.

� Over that, apply two coat of Top coat B. Guard approximately 2feet around the pipe.

Note:- This treatment is a life long treatment & may be adopted for making new

Khurra as per requirements.

6.5 Permanent Repairing System for Industrial Floor, Roads & Joints Products: Cinter SL Screed ‘J’: 1.6 Kg/sqm/mm thickness Exposed Concrete Road

� Dismantling the loose concrete from the pot holes/ joints.

� Using the conc. Cutter to give the proper shape.

� Repair the pot holes with Cinter SL Screed ‘J’ mix. Inside the Factory Shed floor

� Cut the damaged corner floor/ floor joint by concrete cutter.

� Remove the loose conc. From the damaged floor.


� Filling the joint/ Concrete floor by Cinter SL Screed ‘J’ mix.

6.6 Water Proofing of Sub Station ( MRS )

� Remove the existing treatment such as Tarfelt, Tile upto RCC Roof level.


� Sealing of all cracks and joints with BPG 700/ Crackseal RTV.

� Pressure Grouting the surface wherever it is required.

� Apply one coat of B Guard Primer.

� Over the Primer coat apply top coat of B Guard .

� Again relaying the mud phuska, tile terracy over the waterproofing coating to make the proper s lope

6.7 Waterproofing Treatment of Factory Shed Products: BPG 700 Primer NP: 3gm/Metre & BPG 700 compound : 85 gm/Metre Sealing of Sky Lights

� Clean the existing treatment from the glass & channel joints.

� Apply one coat of BPG 700 Primer.

� Over the Primer coat apply BPG 700 compound.

Waterproofing Treatment of ACC Gutters

• Clean the joints & surface. Remove the existing treatment.

• Sealing of all joints & nut bolts by BPG 700 compound..

� Apply one coat of B Guard Primer & over that apply Top coat of B Guard.

6.7 Sealing of Expansion Joint at Hospital Building ( 25mm width )

� Dismantling the existing expansion joint, tile, mud phuska upto RCC Roof level. � Clean the surface & joints thoroughly. � Fixing the Aluminum Sheet as per drawing with BPG 700. � Laying the PCC using High Bond – 40 as a bonding agent. � Again top of the joint seal with BPG 700 compound.

7.0 Some Modern Water Proofing Coatings( Polymer/ Rubber Based)

7.1 Chemistic Rubberized Water Proof Coating Manufacturer: M/s chemisol Agencies

• Single component. Ready to use. Black colour. • Can be applied on damp surfaces. Excellent adhesion to all building materials. ( Apply chemistics clear water proofer as a primer coat first ). Uses: Water proofing of terraces, Basement, Water tanks, AC/GI Sheets. Coverage per litre: Rough-34-40sqft. Smooth: 1st coat-40-45sqft. 2nd:50-55 sqft.

7.2 Chemistic White Water Proofer Coating Manufacturer: M/s chemisol Agencies

• Rubberized water proofing coating s ingle component. White colour. Abrasion Resistant,

washable. Persons can walk over it .

• Can be used as under coat or over coat. Reduces temp. of interior because of UV reflection property. Excellent adhesion to all building materials.

• Cannot be applied on damp surfaces ( Apply chemistics clear water proofer as a primer coat

first ).

Uses: Water proofing of roofs, terraces, Basement, Water tanks. Coverage per litre : 1st coat-50-55sqft. 2nd:65-70 sqft. 7.3 Tarothane Manufacturer: M/s choksey Chemicals

� Two component coating made of high quality Tar with polyurethane. White colour. � Can be used over existing Tar/ Bitumen treatment. Does not require recoating year after year.

Cannot be applied on damp surfaces. � Excellent adhesion with concrete , AC Sheet & Steel. � No primer required for concrete surfaces.

Uses: Water proofing of roofs, terraces, AC Sheets, Toilet sunken portion, metal/concrete tanks & Pipe lines.

Coverage per Kg: 4-5 sqm.

7.4 Mastercreet Manufacturer: M/s choksey Chemicals

� Polymeric modifier for cement. To be used in the ratio of 2:1 ( 2 cement * 1 mastercreet) for water proofing coating.

� Can be used for mixing in cement paint to improve durability & to prevent discoloration ( Mix 5% of cement ) .

Uses: Water proofing of Tanks, To improve adhesion , durability, corrosion resistance,

Impact Strength of cement (Mix 5-10% of cement paint ) . Coverage per Kg: 1 kg sqm . 7.5. Brush bond Manufacturer: M/s FORSOK Chemicals

� Acrylic Polymer modified cementitious coating (Two components Brushbond powder & Nit bond BB Acrylic emulsion).

� Can be used for mixing in cement paint to improve durability & to prevent discoloration ( Mix 5% of cement ) .

� To be applied preferably on damp surfaces. Uses: Water proofing of roofs & water Tanks etc. Strength of cement.

7.6 Tech coat Manufacturer: M/s choksey Chemicals

� No primer required for concrete surfaces. � Polyurethane Rubber based coating ( To be applied on dry surfaces. No primer needed ).

Uses:

� Water proofing of roofs, terraces. � metal/concrete tanks as inner & outer coating. � Protective coating on wood. � Exterior coating on walls.

Coverage per Litre : 4-5 sqm per coat. 7.7 . Sealer Coat and Sealoxy Manufacturer: M/s chitra insultec , Ahmedabad

� Is reasonably elastic to take care of minor structure movements without cracking. Two component coating made of high quality Tar with polyurethane. White colour.

� Can be used over existing Tar/ Bitumen treatment. Does not require recoating year after year. Cannot be applied on damp surfaces.

� No primer required for concrete surfaces. � Polymeric compound, Has excellent adhesion with any surface.

Uses: Water proofing of roofs, terraces & walls. Seals all hairline cracks. Can be tinted to

any colour shade. Has a thin film coating. Sealoxy can be mixed in lime & cement paint ( 2% to 5%) to improve their adhesion & durability. Coverage per Kg: 4-5 sqm .

7.8 Coatings which can be done over Damp Ceilings & Damp Walls to Prevent Seepage

7.8.1 Techoxy Manufacturer: M/s choksey Chemicals

� Water thinable epoxy ( can be applied on damp surfaces also) .

� Can be overcoated with enamel paints excellent adhesion.

� No primer required.

Uses:

� Water proofing of Tanks ( on inside).

� Interior Walls . Coverage per Kg: 1st Coat: 8-9 sqm & 2nd Coat: 10-11 sqm .

7.8.2 Chemistic Damp Proofer

Manufacturer: M/s chemisol Agencies

� Single Component , can be applied on Damp Surfaces.

� White colour Stainer can be mixed to give required colour.

� Primer not needed.

� Painting if required can be done directly over it.

� It is especially useful at interior locations where seepage is already occuring.

� Uses: Damp proofing of Toilets, Interior Walls, Basements, Underground Tanks. on inside).

� Coverage per Litre: 5 sqm for smooth surfaces .

7.9 Some Flexible Sealants (To seal gaps, Joints, Cracks etc which Exhibit Movement)

7.9.1 Crackseal Manufacturer: M/s chemisol Agencies

� One Component white sealing compound on an Acrylic base which hardens to plastic elastic

putty with high elasticity. � Surface to be preferably wet before applying. � Highly elastic & ductile in wide temp. variations. � Does not shrink, crack or crumble. � Painting if required can be done directly over it. � Excellent adhesion to all building materials. � Application by spatula trowel, putty knife or by finger.

Uses: For filling cracks, joints & gaps of Doors, Windows, Concrete Slabs, Masonry

Surface, Glass, tiles, pipes, AC/G.I. Sheat, Wash Basins and sinks . Coverage per Kg: 6 r. m. for groove of 1cm by 1cm.

7.9.2 Techmast

Manufacturer: M/s choksey Chemicals

� One Component butyl rubber based sealant.

� Should be applied on absolutely dry surface.

� Movement accommodation 15% of total joint width.

� Uses: Sealing of cracks in buildings, roofs, terraces, walls.

� Sealing of cracks in Concrete water tanks.

� Sealing of joints in pipes & aluminium ducting to prevent leakages .

� Sealing of small joints between Windows & Door frames and surrounding bricks concrete &

stonework.

7.9.3 Techseal Manufacturer: M/s choksey Chemicals

� Two Component polysulphide based sealant. One component is liquid polysulphide primer. 2nd Component is an accelerator containing a chemicle curing agent.

� After mixing it forms a strong rubber like substance which is highly elastic, flexible and has

outstanding resistance to weathering chemicles and excellent adhesion to all Building Materials.

Uses: Used where movement of joints is more & joint is subjected to high wear & tear and

more resistance to weathering chemicles is required. For example:-

� Expansion joints, joints in water retaining structures ( Dams , Canals etc).

� Joints in basements, retaining walls, joints in Bridges, Roads, Car parks and joints in industrial heavy duty floor.

7.9.4 Chemistic Rubberized joint filler Manufacturer: M/s chemisol Agencies

� Single Component , Black colour Sealant.

� Highly elastic & ductile in wide temp. variations.

� Does not shrink, crack or crumble.

� Painting if required can be done directly over it.

� Excellent adhesion to all building materials.

� Application by spatula trowel, putty knife or by finger.

Uses: For filling cracks, joints & gaps of Doors, Windows, Concrete Slabs, Masonry Surface, Glass, tiles, pipes, AC/G.I. Sheat, Wash Basins and sinks.

� Coverage per Kg: 6 r. m. for groove of 1cm by 1cm.

7.9.5 PIDISEAL PS Manufacturer: M/s Pidlite

� Two part polysulphide sealant available in two variety – gungrade & pouring grade.

Uses: Sealing Movements joints in all types of construction ( especially used for expansion joints).

7.9.6 RHODORSIL 3B RTV Silicon Sealant Manufacturer: M/s Pidlite

� One component Silicon Sealant.

Uses: Sealing joints, gaps, cracks ( Movement accommodation 35% of joint width)

7.10 Rigid Sealants (To fill gaps, Joints, Cracks etc which don’t Exhibit Movements) 7.10.1. Poly Seal Manufacturer: M/s Greenboro

� Two component Epoxy putty.

Uses: For filling or sealing cracks, gaps, holes, joints in Wood, Concrete, Metals and ceramic ( where there is no movement of joints).

� Should not be used for hot areas.

7.10.2 M - Seal Manufacturer: M/s MECP( Mahindra Engg. & Chemical Products Ltd.) � Two component( Resin & hardner) Epoxy putty.

Uses: For filling or sealing cracks, gaps, holes, joints in Wood, Concrete, Metals and ceramic

( where there is no movement of joints) � Should not be used for hot areas.

7.10.3 Metal Putty or MC putty (DUCO )- Seal Manufacturer: M/s ICI ( India)

� Single component hardens in 2-3 hours.

� Uses: For filling holes in Steelwork, finishing of weld etc.

7.10.4 Feviseal Manufacturer: M/s Pidlite

� Two component Epoxy putty.

� Sets hard within 20 mts.

� Final curing strength achieved in 4 hrs.

� Should not be used for hot areas .

Uses: For filling or sealing cracks, gaps, holes, joints in Wood, Concrete, Metals and ceramic ( where there is no movement of joints).

7.11 EMERGENCY WATER PROOFING

Thunderproof Manufacturer: M/s choksey Chemicals

� Two component, solventless synthetic Polymer based compound which dries even in presence

of water.

� It forms an impermeable, tough film which is absolutely waterproof & highly resistant.

� It is a wonder product which gives relief from water leakages even while its raining.

� THUNDERPROOF is a quick setting repair product especially designed for EMERGENCY repair under any circumstances.

Benefits of Thunderproof

� Instant leak repairer, Cures in presence of Rain, Snow & below freezing temp. � Cures to a tough & abrasion resistant waterproof film. � Easily applicable by brush or trowel, Seals localized cracks & surface porosity. Can be

reinforced to cover breaks & cracks. � Bonds strongly to most of the building materials. � No primer is required.

Methods of Using Thunderproof

� Clean the surface. Mix part-I & Part- II homogeneously. Allow the mix to mature for 5 minutes

� Apply on cracks with brush or Trowel.

� For wider cracks make Thunderproof putty by mixing 1Kg: 350gram (Thunderproof & white Portland cement respectively). Fill the wider cracks & then apply Thunderproof coating.

� Applicable on concrete, cement, plaster, asbestoes sheets etc

Uses: Instant leak repair of cracks, joints & porous substrates( resistance to positive water pressure). Building roofs, terraces, Chimney bases, Gutters, Water channels, Bridges, Dams

SUMMARY � Leakages to great extent can be minimized by ensuring good quality construction i.e. by close

supervision & using materials of approved make. � The durability of conc. not only depends on its strength but also on the permeability of the conc.

Therefore, waterproofing should be made mandatory for all s tructures. During construction, the integral waterproofing compound either in powder or liquid form can be introduced in conc. to improve the waterproofing characters by optimizing the water cement ratio. Now with the invent of latest technology polymer based waterproofing systems, it is much easier & effective to achieve waterproofing properties .

FLOOR TRAP2

� Mechanism of Water Entry

� Preventing Water Entry

(By Extending slab itself)

� Preventing WATER ENTRY (By making brick or concrete cornice

� WATER PROOFING FOR SUNKEN FLOORS

� PROOFING FOR SUNKEN FLOORS (SECTION

� WATER TANK ON ROOF

� WINDOW SILL (DAMPNESS PREVENTION MEASURES IN BUILDING AT WINDOW SILL)

� DRAINAGE OF ROOF

� Expansion joint1

� Water proofing of roof1

� WC1

� WC2

damp prevention in buildings

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