Water proofing in buildings
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Waterproofing is done to prevent water from penetrating buildings. It involves applying membrane barriers like bitumen or PVC during construction. It can also be done later to address leaks. Common areas waterproofed include bathrooms, terraces, basements, and roofs. Materials used include cement, sand, metal chips, brick bats, and waterproofing chemicals. Techniques include applying cement coats sloped away from the building, with brick bats or tiles in between coats. Thorough preparation and multiple curing coats are important for effective waterproofing.
Water proofing in buildings
- 2. 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 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.
- 3. 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.
- 4. 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
- 5. 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
- 6. 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
- 7. WATER PROOFING WATER PROOFING TECHNIQUES Concrete RepairDeck Coating/Traffic Topping Epoxeal GS & Carbon Fibre Fillmore Expansion Joint Systems Epoxy healer sealer
- 8. 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
- 9. 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
- 10. 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
- 11. 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
- 12. 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
- 13. 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
- 14. 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
- 15. 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.
- 16. 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
- 17. 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
- 18. 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
- 19. Details of glazed china mosaic water-proofing WATER PROOFING BRICK BAT COBA FOR TERRACE
- 20. 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
- 21. 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
- 22. 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
- 23. 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
- 24. 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
- 25. 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
- 26. 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.
- 27. 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.
- 28. 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.
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