Water-proofing

Building water-proofing is a process which is designed

to prevent water from penetrating a building.

Usually extensive waterproofing measures are added to a

building at the time of construction, to provide moisture

control from the start

Waterproofing may also be done after a building is built,

to address problems as they emerge or as part of a

building retrofit.

WATER PROOFING

INTRODUCTION

Water proofing is done in various parts of the building

which include-

1.WC

2.Bathrooms

3.Terrace

4.Roofs and Chejjas

5.Basement, swimming pools, underground ducts.

6. Under ground and overhead water tanks.

Water-proofing maintains the appearance of the building

and increases the life of the structure.

Construction waterproofing

In building construction, a structure needs waterproofing since concrete itself will not be watertight on its own

(but note concrete is easily waterproofed with additives).

The conventional system of waterproofing involves 'membranes'. This relies on the application of one or more

layers of membrane (available in various materials: e.g., bitumen, silicate, PVC, EPDM etc.) that act as a barrier

between the water and the building structure, preventing the passage of water.

A safer foundation

Exposure to weather conditions like heavy rain and sunlight could cause structural problems. If wooded decks

etc is not properly waterproofed, we can notice discoloration, water stain, rotting and fungi growth.

Walls not properly waterproofed will give in hydrostatic pressure creating cracks and leaks on walls and floors.

Why water proof structures?

WATER PROOFING REASON FOR WATER

PROOFING

Healthier environment

• Humidity and moisture is what moulds and mildew want. Mould and mildew could

cause respiratory problems like asthma and also trigger allergic reactions. There is no way

to remove these fungi’s spores inside the house, the only thing that could remove such

growth would be to control moisture.

• Moulds do not only grow on walls or areas where there are moisture issues. It could

grow on anything like wood, carpet and even food. By reducing humidity, preventing

condensation and water seepage, mould and mildew growth could be decreased.

Eliminate insect growth

• There are various kinds of insects, water bugs, cockroaches, beetles, and critters that

find heaven in damp areas.

Wet basements are ideal for wood boring insects like termites to reproduce.

• These insects could cause damage not only to the foundation but also to important

things stored in the room.

Cement : Ordinary Portland cement is used for all water-

proofing works…type?//pproperties

Sand : Clean river sand should be used for water-

proofing work. If muddy, the sand should be

washed before use.

Metal : Hard angular metal of sizes varying from 12mm to

20mm is used for water-proofing works.

Brick bat: Brick bats should be well burnt pieces of bricks

having proper thickness. Underburnt or

overburnt brick bats should not be used for

water-proofing work.

Water-proofing chemical/powder :

A number chemicals and water-proofing

compounds in powder form are available in the

market. Some chemicals include

-tar/bitumen based compounds

-inorganic compounds with little percentage of chlorides and sulphates.

-acrylic based compounds.

-epoxy resins.

-silicones.

-polysulphides and polyurethanes.

Materials used for Water Proofing

WATER PROOFING WATER PROOFING

MATERIALS

Bitumen - Mixed with a filler component such as limestone or sand.

Polymers are added to the bitumen such as APP (atactic polypropylene) a

plastic additive that gives rigidity and tear resistance, or SBS (styrene

butadiene styrene) a rubber additive that gives more elastic benefits.

Base Products - Polyester, fiber glass, rag fiber (hessian), and paper. These

products are bought in roll format and are pulled through the bitumen

mixes on huge rollers. The base product becomes saturated in huge tanks

by the tar like bitumen substance, creating rolls of waterproof material.

Water Proofing Chemicals

WATER PROOFING WATER PROOFING

CHEMICALS

Techniques of Water proofing

WATER PROOFING WATER PROOFING

TECHNIQUES

Spray Waterproofing Cavity Wall WaterproofingSheet Membrane Waterproofing

Surface Applied Coating Hot Rubber Waterproofing Blind Side Waterproofing

WATER PROOFING WATER PROOFING

TECHNIQUES

Concrete RepairDeck Coating/Traffic ToppingEpoxeal GS & Carbon

Fibre Fillmore

Expansion Joint Systems Epoxy healer sealer

Waterproofing membrane systems include both negative and positive side waterproofing.

Positive side waterproofing systems are applied to the face of the element that is directly

exposed to moisture, the exterior face.

Negative side waterproofing systems are applied to the surface of the element opposite

the surface exposed to moisture.

Positive systems are available in numerous materials and forms. Negative systems are

limited to

cementitious systems.

Water proofing Membranes

WATER PROOFING WATER PROOFING

TECHNIQUES

Water Proofing membranes can be classified into four types

Cementitious Systems—These systems contain Portland

cement with and sand combined with an active waterproofing agent.

These systems include metallic, crystalline, chemical additive and

acrylic modified systems. These systems can be applied as negative or

positive side waterproofing.

Sheet-Membrane Systems—Sheet

membranes used in below grade applications are similar

to the materials used in roofing applications and include

thermoplastics, vulcanized rubbers and rubberized

asphalts. The thickness of these systems varies from 20

to 120 mils.

Fluid Applied Systems—These systems include

urethanes, rubbers, plastics and modified asphalts. Fluid

membranes are applied as a liquid and cure to form one

monolithic seamless sheet. Fluid systems can be applied to

vertical and horizontal applications. For foundation wall

applications typical fluid applied systems are 60 mils in

thickness.

Bentonite Clays—Natural clay systems, known as

bentonite act as waterproofing by swelling when exposed

to moisture thus becoming impervious to water. This

swelling can be 10 to 15 percent of the thickness of the

base material. Clay panels and sheets are popular for use

in blind-side waterproofing applications such as on

retaining earth systems and elevator and sump pits

Preparation of WC water-proofing

The pre-work should be completed before starting the water-proofing :

Completion of internal plaster of walls leaving a margin of 18” from the final floor

level of WC unit.

Completion of grooving or chasing for concealed G.I. piping or electric conduit piping in WC.

Removing of all debries from WC and chiselling the extra mortar to expose the rare slab completely.

Completion of making holes in external walls for connecting nahini trap, p-trap, floor trap, etc to the external drainage line.

Thorough cleaning of WC with sufficient quantity of water.

Level marking in red color on wall with respect to floor level to setup trap level.

WC Water-proofing

WATER PROOFING WC WATER

PROOFING

•Fill up the WC slab with 7cm of water(after plugging trap hole)

•Keep the slab filled with water over-night for atleast 12 hours.

•Check for leakages in base slab or underneath.

•If a major leakage is observed, locate the spot with porous concrete and provide a socket for grouting. In

addition provide 4 sockets at each corner of the slab.

•Grout the socket with cement slurry with consumption rate of 1 bag of cement to 75 to 100lts of water. To

spread the slurry in the porous portion of the concrete, it is required to flow the slurry with velocity.

•It is further understood that the process of socketing and grouting is to be continued until the leakage in

base slab is totally stopped.

•After completion of cement grouting and testing for leakages, remove the sockets.

Socketing of WC water-proofing

Provide 25-40mm thick cement mortar base coat in proportion 1:4

with a slope of 1:100 from the entrance door towards the water escape

pipe (drain pipe).

Carry out this base coat on all walls upto a height of 45cm above

toilet finished floor level

Keep this base coat full with water upto the slab drop top, for

minimum 4 days for curing and testing purposes.

WATER PROOFING WC WATER

PROOFING

Coating for WC water-proofing

•Select well burnt brick bats. Before laying brick bats,

sock thoroughly in water for atleast half an hour.

•Lay the brick bat on the edge and not on the flat

surface.

•Any gaps between the bats should be filled with

mortar. Complete the brick bat coat with joints filled

with cement mortar in 1:6. Also use water-proofing

compound as per the specified dose per bag of cement

while filling the joint.

•Give a slope of 1:100 in brick bat coat from the

entrance door to the water escape pipe.

•Cure the coat by ponding water for four days and

check for any leakages.

Brick coat for WC water-proofing

After curing of the brick bat coat, complete

the topping coat with 1:4 cement mortar

mixed with water-proofing compound. Finish

this coat properly with neat cement slurry by

metal float.

Roughen the surface with a wire brush, for

bonding of the horizontal filler coat. Continue

this coat on the side walls, upto 45cms above

WC floor level. This coat should not project

out beyond the plastering coat of the WC

walls, so as to avoid unnecessary thickness of

the glazed tile dado.

Cure this final coat for a minimum of 7 days,

with water upto minimum 7.5cms depth.

WATER PROOFING WC WATER

PROOFING

Topping coat for WC water-proofing

WC pan fixing and finishing of water-proofing

• Fix WC pan at the required level, considering 15mm sunk from the floor level.

• Block the p-trap outlet hole with gunny bags and fill the WC pan with sand to prevent any

damage by the water-proofing workmen.

• Check the WC pan for its centre.

• Fill the extra gap around WC pan over the topping coat with brick bat and mortar in layer upto a

minimum of 7.5cm below the top of WC.

• Allow curing for a minimum of 3 days.

• The final topping coat should be done upto 50mm below top of WC with a slight slope towards

the WC pan.

• Roughen the top coat surface with a wire brush to receive the mortar with the required bonding.

• Continuous curing should be done for a minimum of 7 days with wet gunny bags.

WATER PROOFING WC WATER

PROOFING

After completion of the internal plastering of walls, keep a margin of 450mm from the final floor

level of the bathroom. Roughening of the plaster should be done with a wire brush for fixing the

glazed tiles cladding dado.

Complete grooving, chiseling for concealed G.I and electrical conduit piping in bathroom.

Remove all debris from the bathroom after chiseling the extra mortar, if any, to expose the slab

completely.

Make the holes in the external walls for connecting nahini trap to external drainage line and water

leakage drain pipe.

Clean the bathroom thoroughly with water. Mark the level in red on the walls, with respect to the

floor level, to set up the trap level.

Preparation of Bathroom water-proofing

Bathroom Water-proofing

WATER PROOFING WC WATER

PROOFING

After curing the brick bat coats, complete the topping coat using 1:4 cement mortar mixed

with water-proofing compound, with a proper slope from the entrance door to the nahini trap.

Finish this coat with cement slurry using a metal float. Roughen the top coat using a wire

brush to receive tile mortar bonding.

Ensure that this coat on walls does not project beyond the bathroom wall plastering coat.

Cure this final coat for a minimum of 7 days with standing water (depth 7.5cm)

Topping coat for Bathroom water-proofing

WATER PROOFING BATH ROOM WATER

PROOFING

Base Coat for bath water-proofing

• After stopping any leakages in the base slab, provide

15-25mm thick cement mortar base coat in proportion

1:4 with a slope of 25mm in 3m from entrance door

towards nahini trap.

• This base coat should cover all the walls around upto

the outer face wall line at the entrance door and the

bottom portion of the nahini trap connection hole

made in the wall.

• Flood this base coat with water, upto the slab drop, for

a minimum of 4 days, for curing and testing.

• Fix the nahini trap and drain pipe over this base coat.

• The brick bat coat is done similar to WC water-

proofing.

For basements, swimming pools and underground ducts such as lift pits, the water-

proofing has to withstand the water pressure in addition to its basic stress.

Basement/Swimming pool and underground duct water proofing

WATER PROOFING BASEMENT, DUCT AND SWIMMING POOL WATER

PROOFING

• Carry out the work of PCC bed and provide a cement mix 1:4 base coat with water-

proofing compound and above this fix rough shahabad tiles.

• Maintain the break joint pattern while fixing the tile for base.

• After fixing the tiles, grout the joints with cement slurry completely.

• Apply a jointless layer of cement mortar 1:3 25mm thick and cure it for 7 days.

• For basement, provision of gutter and sump is made in PCC itself and shahabad

base is also prepared in the same fashion. Gutter is given proper slope towards the

sump. This is done as a preventive measure against occasional entry of rain water

into basement.

• After curing, provide the final jointless water-proof plaster coat in cement mortar

1:4 over the rough shahabad tiles.

Work procedure

Fix in a slope of 1:150, starting from the lowest point of rainwater down

take and by keeping a minimum thickness of 65mm below the rainwater

outlet.

Fix brick bats in cement mortar layer of 1:6 proportion in a slope of 1:150

with the water proofing compound.

Brick Bat Coba For Terrace

WATER PROOFING BRICK BAT COBA FOR

TERRACE

Fill the cement mortar 1:4 with the brick bat joints.

Fix small pieces of brick bats along with 20mm metal for coving of

watta(rounding) at the bottom of the parapet wall

Special care should be taken for achieving the round shape near the rain

water pipe.

Block the rain water outlet with gunny bags, to avoid cement slurry from

entering it.

Cure the brick bat coba coat for at least seven days.

WATER PROOFING BRICK BAT COBA FOR

TERRACE

Details of glazed china mosaic water-proofing

WATER PROOFING BRICK BAT COBA FOR

TERRACE

Final coat for terrace water-proofing

Spread cement mortar in 1:4 along with water-proofing compound over the

brick bat coba.

Press the cement mortar with a ruler of length of 2m.

Level the surface with a wooden float, keeping 25mm thickness.

Apply thick cement slurry over the levelled surface, along with the water-

proofing compound for a smooth finish.

Polish the surface with metal float

Make vertical and horizontal lines at an intervel of 300mmX300mm, using

a cotton line dori of minimum 3mm thick; so as to avoid cracking of the top

layer.

Clean and cure the final coat for 21days with atleast 150mm water standing

on the water proofing.

WATER PROOFING BRICK BAT COBA FOR

TERRACE

Clean the top of the chhajja and chisel extra

mortar, if any.

Apply a thick cement slurry over the top of

the chhajja.

Apply 1:1.5:3screen coat.

Make rounding at the junction of chhajja and

wall of the building.

Cure this coat for seven days.

Apply a finishing coat with C.M 1:4 with

water-proofing compound.

Cure the water-proofing for atleast 7 days.

Chejja water proofing

WATER PROOFING CHEJJA WATER

PROOFING

Clean the surface of the sloping terrace.

Apply a thick cement slurry over the surface of the slab.

Apply 1:1.5:3 screen coat.

Cure this coat for 7 days by putting wet gunny bags on it.

Over this coat, apply a finishing coat with cement sand mortar 1:4 and

water-proofing compound as per design.

Make an edge between the parapet and the sloping roof on the second day.

Cure this water-proofing for 15 days with gunny bags spread over it.

Constant watering is required on a sloping slab.

Sloping Terrace Water Proofing

WATER PROOFING SLOPING TERRACE WATER

PROOFING

Chisel the extra concrete in the tank, particularly in the corners around the

chambers.

Clean the entire tank, along with the bottom slab and side walls and throw away

the debris.

Allow the cement slurry to penetrate all holes, cracks of bottom slab.

Check the hacking of vertical walls from inside for better bonding with water-

proofing.

Over head tank water proofing

WATER PROOFING OVER HEAD TANK WATER

PROOFING

Check the inlet, outlet and washout pipes for their rigidity. If the pipes are not rigid,

grout them to achieve the desired fixity. Before grouting, check the levels of these

pipes and if necessary correct them by shifting the pipes accordingly.

Apply water-proofing plaster in C.M 1:4, by adding water-proofing compound.

Apply 15-20mm thick over this plaster, particularly on the corners and base for

avoiding shrinkage and to achieve better strength.

The bottom of the top slab does not require water-proofing.

The top of the overhead water tank is to be finished with brick bat, as mentioned

for terrace water-proofing.

Allow the water-proofing to set foe atleast 12 hours

Cure this water-proofing for a minimum of 15 days.

WATER PROOFING OVER HEAD TANK WATER

PROOFING

Surface Preparation For Expansion Joint Water Proofing

• Clean the joint surface of dust, cement mortar etc.

• Remove oil and grease(if any) from the surface.

• Protect the edges of the joint with masking tape.

• Keep the tools like suspended scaffolding, ladder, spatula,

putty knife, hand held gun equipment etc. ready.

Work procedure for vertical expansion joint water proofing.

•Primer is applied in the joint in accordance with the type of joint. For

surfaces like concrete, masonry etc.

•After the primer dries completely, sealant is prepared by mixing base and

accelerator. Mixing should continue till a uniform color is obtained.

•The base and accelerator are mixed in equal proportions by weight.

•This mixed compound is then applied with a spatula or hand held gun

equipment wherever required. Extra material is cut off with putty knife and a

smooth vertical joint is created.

•The masking tape is then removed and the surface is cleaned with suitable

solvents.

WATER PROOFING EXPANSION JOINT WATER

PROOFING

Expansion Joint Water-proofing

WATER PROOFING DAMP

PROOFING

Damp proofing

Dampness is the seepage of water through the members of the building.

There is very little difference between leakage and dampness.

If the water comes out of slab of the bathroom/toilet, it is termed as leakage and

if it is observed on external walls of the building directly exposed to rains and

floors, then this percolation is termed as dampness.

WATER PROOFING DPC IN

PLINTH

Damp proof course in plinth

•Foundation masonry is always in contact with the sub

soil,which sometimes may contain water.

•The subsoil water tries to enter the building through the

walls/floore.

•Due to capillary action, the subsoil water sometimes rises

into the walls of the building against gravity and indicates

dampness.

•Generally , foundation masonry is done with UCR masonry

and at the plinth level,DPC is provided to prevent capillary

water of the sub soil water.

•The rich cement concrete, generally of M20 grade with

water proofing compound added to it can be used as DPC in

buildings.

•Tar isalso applied below DPC to prevent the entry through

capillary action.

•Above the DPC, regular masonry for super structure is

done.

WATER PROOFING WALL

DAMPNESS

Causes and Precautions for wall dampness

•If the foundation masonry is directly exposed to subsoil, water may

enter the building through the walls.

•For this it is ensured that pointing or plastering the exposed walls is

done to restrict the direct contact of sub soil water with masonry.

•No hollow spaces should remain in the masonry as these are the

routes for water to enter.

•For the junctions of RCC and masonry, chicken mesh should be

used for plastering.

•Dampness is also observed on the ceiling in the form of patches.

This is due to stagnant water on the terrace or some organic matter

dumped on the terrace.

•During execution of the terrace, a proper slope should be given so

that water doesnt accumulate in any place.

•The terrace must be kept clean during rainy seasons to prevent

continuous dampness.

•The terrace slab must be cast carefully so that it attains density and

impermeability.

Thank you…