this slides is about how and why are waterproofing is important in building and also provides the long life to building.

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Waterproo
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Building construcions-5

2. Waterproo
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• Building water proofing is a process which is designed to prevent water from penetrating a building.
• Usually extensive water proofing measures are added to building at the time of the construction ,to provide moisture
control from the start.
• Water proofing may also be done after a building is built ,to address problems as they emerge or as part of a building
retrofit.
Water proofing is done in various parts of the building which include
• WC
• Bathrooms
• Terrace
• Roofs and chajjas
• Basement
• Swimming pools
• Underground ducts
• Underground and over head water tanks
Water proofing maintains the appearance of the building and increases the life of the structure

3. CONSTRUCTION WATER PROOFING
• 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 WATREPROOF STRUCTURES ?

4. HEALTHIER ENVIRONMENT
• Humidity and moisture is what moulds and mildew
want.
• moulds 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, moulds 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.

5. Materialsusedforwaterproo
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Cement :
Ordinary Portland cement is used for all water- proofing works.
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-proo
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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.

6. Waterproo
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ingchemicals
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.

7. Advantagesanddisadvantages
Of w
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terproo
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Disadvantages of Water Proofing
•Bitumen based products soften under summer heat due to black color.
•Bitumen based products have a limited life due to solvent evaporation.
•Polyurethane protective coating is not very flexible.
•Polyurethane protective coating hampers the natural breathing capacity of concrete.
•Cementitious waterproofing is the inability to hold up cracks, which further cause leakage.
Advantages of Water Proofing
•Water absorption will be reduced.
•Prevents the formation of cracks on the surface of the concrete.
•Easy application.
•Increases the lifespan of the concrete structure.
•Prevents the rusting of reinforcement.
•Prevents dampness inside the building.
•Prevents seepages from the ceiling and walls.
•It reduces the maintenance coast of the building.

8. Awaterproo
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ingmembrane
• A waterproofing membrane is a thin layer of water-tight material that is laid over a surface.
• This layer is continuous and does not allow water to pass through it.
• For example, on a flat terrace, a waterproofing membrane could be laid above the structural slab and below the finish
tiles.
• This will ensure that water does not seep into the structural slab.
• The tiles and membrane must be laid over a filler material that is sloped to ensure that water flows into sumps and
drains. Any water that remains as puddles over the tiles is likely to seep into the slab over time, so puddles are to be
avoided at all costs
• These membranes are composed of thin layers of waterproof material. Most are about 2 to 4mm thick.

9. Chajjawaterproo
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• Clean the top of the chajja and chisel extra mortar,
if any.
• Apply a thick cement slurry over the top of the
chajja.
• Apply 1:1.5:3screen coat.
• Make rounding at the junction of chajja 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

10. Slopingterrace
W
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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.

11. Overheadwatertank
W
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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.
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 at-least 12 hours
Cure this water-proofing for a minimum of 15 days

12. DPCinplinth
•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/floor.
•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 is also applied below DPC to prevent the entry
through capillary action.
•Above the DPC, regular masonry for super structure
is done.