1. SEMINAR ON
WATERPROOFING TECHNIQUES
CONVECTIONAL
SANCHIT AGRAWAL
ROLL NO- 42

2. INTRODUCTION
• Water infiltration causes major problems to a
structure. Water damages a building first
cosmetically then structurally. Hence to keep our
building safe & healthy water proofing is an
important activity.
• It maintains appearance of building
• Increases life of structure
• Keeps away foul smells which may arise due to
dampness
• Also check the algae & plant development

3. Sources of Dampness :
1.Geological & climatic causes:
• Rain penetration
• Ground moisture rise
• Drainage of the site
• Orientation of the building
• Atmospheric moisture
2. Structural Causes:
• Water introduced in the structure during
construction
• Defective construction

4. Prevention:
Basements:
• Underground water reservoirs & basements
have to be made proof against leakage or
seepage of water as follows:
a)From inside the structure to the surrounding
ground, and
b)From the surrounding ground towards the
inside of the structure.

5. Suitable precautions shall be taken to avoid cracks and
leakages resulting from the following:
• Movements due to shrinkage and creep,
• Movements due to variation of temperature and
humidity.
• Movements due to dissipation of heat generated
by the concrete in the process of hydration,
• Damage to the concrete by the percolation of
chemically aggressive liquids from outside,
• Damage due to uneven settlement of
foundations,
• Cracking of concrete caused by rusting of bars.

6. IMPREGNATION WATER PROOFING (PRE
CONSTRUCTION) TREATMENT (BOX METHOD)
CITATION
a. R.C.C. WALL
b. R.C.C. FLOOR SLAB/ RAFT
c. LEAN CONCRETE BASE
(1:5:10, 1:4:8, 1:3:6)
d. 20mm THICK “ACRYLIC
COMPOUND MIXED’ WITH
CEMENT MORTAR 1:4 WITH
STONE AGGREGATE (12mm
DOWN) EMBEDDED AT
RANDOM.
e.15 TO 20mm THICK ROUGH
QUARRY STONE SLABS OVER
15mm ACRYLIC COMPOUND
MIXED CEMENT MORTAR 1:4.

7. f. 20mm THICK ‘ACRYLIC COMPOUND MIXED WITH
CEMENT MORTAR 1:4 WITH STONE AGGREGATE
(12mm DOWN) EMBEDDED AT RANDOM.
g. 15-25mm THICK ‘GAP BETWEEN STONE SLABS
GROUTED WITH ACRYLIC MIXED CEMENT GROUT.
h. 15-20mm THICK ;ACRYLIC COMPOUND MIXED
GROUT.
i. 15-20mm THICK ROUGH QUARRY STONE SLABS.
j. 15-20mm THICK ‘ACRYLIC COMPOUND MIXED
CEMENT PLASTER 1:4.

8. Work Procedure:
• Over P.C.C. base coat of 1:4 cement mortar shall be laid.
• 600 X 600 rough quarried 32-40 mm thick stone slabs laid
over with a minimum width of joint between two tiles.
• After fixing stone slabs, joints shall be grouted with cement
slurry & seal them with 1:4 C.S. mortar.
• Over this layer joint less layer of mortar shall be laid @25 mm
thick& 1:3 C.S. mortar.
• In sumps & gutters this process shall also be done.
• Over the plastered stone slab, R.C.C. Raft is laid & walls are
erected.
• Rough stone slabs then fixed on outside plane of R.C.C. walls
over neat cement paste up to 450 mm above the ground.
• Joints then sealed with 1:2 C.S. mortar, process is called
Pointing.

9. Continue……
• Grouting is done with cement slurry for 3-4
days until back of stone slabs are completely
filled @ 1.5 bag of cement in 100 litre water.
• Curing is required for 7 days at least @ 10
times a day.
• Final joint less waterproof plaster coat in 1:4
C.S. mortar is done over rough stone slabs.

10. TREATMENT INTERNAL TANKING IN MASTIC
ASPHALT (POST TREATMENT)

12. Terrace:
• Terrace is major
point of getting
dampness &
water into
building as it is
directly exposed
to the weather
conditions.
Besides doing
water-proofing of
the terrace, some
precautionary
measures shall
also be taken in
consideration.

13. Preparation of terrace water-proofing:
• Chisel extra mortar on terrace.
• Clean terrace with water.
• Spread cement slurry @1bag in 100ltr water
• Ensure correct location of RWP
• Collect brick-bats & soak them before use.

14. Brick Bat Coba Coat for Terrace Water-Proofing:
• Fix in the slope required, keeping minimum
thickness of 65mm.
• Fix in position brick bats using 1:6 C:S mortar
in a slope of 1:150.
• Fill in cement mortar 1:4 with water-proofing
compound in the brick bat joints.
• Round shape near RWP & corners is essential.
• Curing for at least 7 days is necessary.

16. Final Coat for Terrace Water-Proofing:
• Spread cement mortar 1:4 along with water-proofing
compound over brick bat coba.
• Press the cement mortar with a ruler of length of 2 m.
• Level the surface with a wooden float, keeping 25 mm
thickness.
• Apply thick cement slurry with water-proofing
compound for a smooth finish.
• Make vertical & horizontal lines @30cm X 30cm with
3mm thick dori.
• Clean & cure the final coat for at least 21 days, with
6”water standing over water-proofing.

17. Toilets & Bathrooms:
In toilets dampness may take place due to various
reasons, primarily it may leak due to:
• Poor workmanship in drainage & water supply
system
• Bad quality material used for the purpose of
drainage & water supply
Preparation for W.C. Water-Proofing:
Completion of internal plaster of walls, leaving a margin
of 18” from final floor level of W.C. unit.
•All grooving/chasing of concealed pipes/ conduits done.
•Remove all debris & chisel out extra mortar.

19. Water-Proofing Process:
• Provide 25-40 mm
thick 1:4 cement
mortar base coat @
1:100 slope towards
drain pipe.
• •This coat is applied on
walls upto450mm ht.
• •It should cover all
exposed surfaces of
beams, walls .
• •Water is filled for 4
days for curing &
testing.

20. Water Escape Pipe:
• Provide 25 mm G.I./ P.V.C. pipe for water
escape outlet.
Brick Bat Coba:
Well burnt brick bats soaked and then laid on
the base(brick on edge).
•Gaps should be filled with 1:6 cement mortar.
•Slope of 1:100 shall be maintained.
•All the pipes & connections shall be made
water-proof.
•Curing for four days is required.