METHODOLOGY / PROCEDURE OF WET AREAS WATERPROOFING - TOILETS / BALCONY / KITCHENS / OTHERS.

WORK METHODOLOGY OF WET AREAS WATERPROOFING

(TOILETS / BALCONY /  KITCHENS / OTHERS)

 

 STEP-1: `SURFACE PREPARATION:

 

Ø  Concrete surfaces should be fully cured (minimum 28 days) prior to application.

Ø  The concrete surface shall be cleaned thoroughly of all contaminants like dust, traces of curing compound, oil and grease.

Ø  All surface imperfections, protrusions, structurally unsound and friable concrete must be removed and repaired with a suitable concrete repair mortar.

Ø  All surface cracks, undulations and voids shall be repaired appropriately before application.

Ø  All cracks above 5mm deep,  shall be cut opened, cleaned and shall be filled with shrink free crack filling material. i.e. GP2 or equivalent.

Ø  The entire surface to be coated must be in SSD condition prior to application of coating.

Ø  All the construction joints need to be opened and treated with polymer modified mortar (Cement: sand: SBR Latex) or ready to use modified mortar.

Ø  Injection grout shall be done at all construction joints. Nozzle shall be fixed @ 500mm centre to centre at all construction joints.

Ø  3 days ponding test has to be carried out, if the leakages are observed then repeat the above procedure till to achieved water tight toilet area

 

 

STEP- 02 : SEALING OF PIPE INLET / OUTLET DRAINAGE PIPES AND FILLING CUTOUT HOLES

Ø  The surface of the pipe shall be free from dust, laitance, oil and water.

Ø  The core cut shall be free from debris, dust or any foreign materials.

Ø  Bath seal tape need to be unrolled to required length and wrap around the pipe by removing release film from one side of the tape.

Ø  The length of the tape shall be taken in such a way that the overlap of tape maintains to be 150mm.

Ø  Pipe need to be inserted with Bathseal tape or equivalent wrapped into the core and support it with formwork from below the slab or support from the periphery of the wall so that the gap around the pipe and the core shall be uniform throughout.

Ø  The bore packing shall be done with Non-shrink free flow cementitious grout, , so that there is no air entrapment / voids creating

 

 

STEP- 3:  APPLICATION OF TWO PART COMPONENT ACRYLIC POLYMER BASED CEMENTITIOUS COATING

Ø  Top level of the waterproofing shall be marked.

Ø  The entire surface to be coated must be in SSD condition prior to application of coating acrylic polymer based cementitious coating as per approved brand.

Ø  Mixing: Using a slow speed mechanical mixer and a clean suitable mixing vessel, slowly add the powder component to the liquid polymer and stir until a smooth and homogenous slurry is achieved.

Ø  Allow the mixed slurry to stand for 5 – 10 minutes to remove air bobble created during mixing.

Ø  Do not dilute with water during or after mixing.

Ø  Apply mixed cementitious slurry by brush or roller.

Ø  Allow the first coat to dry completely for 6 – 8 hours before applying the second coat.

Ø  Apply second coat at right angles to the first coat.

Ø  Coating to be applied as per recommendation of manufacturer regarding application tool.

Ø  Allow the coating to cure for 3 – 4 days before application of protection layer.

Ø  Cure the applied cementitious slurry for period of 7 to 10 days. Or minimum of 3 to 5days if further activities starts immediately.

 

STEP- 4 : PROTECTION OF COATED SURFACE

 

A.   Protection to waterproof coating (Horizontal Surface)

 

Ø  Cement sand mortar to be laid for protection to the coating laid to slope to the drainage point.

Ø  This mortar shall be minimum 30 to 40mm thick and shall admixed with integral waterproofing compound as per approved brand.

Ø  Cement mortar for base coat shall be used minimum ratio of 1:4

Ø  Curing shall be done at least for 7 to 10 days.

 

 

B.   Protection to waterproof coating (Vertical Surface)

 

Ø  After chemical coat, a rash coat shall be applied for better bonding with cementitious mortar bedding.

Ø  Protection Layer or base coat will be carried out.

Ø  This mortar shall be minimum 15 to 20mm thick and shall admixed with integral waterproofing compound as per approved brand.

Ø  Cement mortar for base coat shall be used ratio of 1:4 .

Ø  Top of base coat shall be trowel finish to receive the block / brick bat upto required level.

Ø  Curing shall be done at least for 7 to 10 days.

 

STEP- 4 : BRICK BAT COBA FOR FILLING OF SUNKEN AREA or TERRACE SLAB;

 

Ø  Level pad shall be prepared as per the required slop towards nahani trap as per drawing or specification.

Ø  Bricks selected for using as brick bat coba shall be either full brick or ¾ brick made out of one complete brick by breaking into required sizes using mallets.

Ø  Brick bat shall be soaked thoroughly for about 15 minutes prior to their placing.

Ø  A thin layer of cement slurry shall be laid on cleaned slab prior to laying of brick bats, cleaning to be ensured before laying the brick bat.

Ø  On applied cement surry, 10 to 20mm thick layer of cement sand mortar in the proportion 1:4 mixed with compatible waterproofing compound shall be laid.

Ø  Approved integral waterproofing admixture shall be mixed with cement mortar as per data sheet.

Ø  Mortar shall be mixed properly and same shall be used within 60 minutes from its mixing time.

Ø  Broken brick bats of required size shall be placed over the cement mortar bed by hand packing having minimum 15 to 20mm gap between broken bricks.

Ø  Pre-soaked brick bats shall be laid in radial by inserting brick bat s to a depth of about 10mm by light tamping.

Ø  Mortar shall be ratio of 1:4 shall be used for filling of gaps between broken bricks.

Ø  Cement mortar shall be filled up to 2/3rd height of the broken bricks.

Ø  Laying of brick bats should proceed from one corner and shall be laid in radial pattern to drain off any water which has seeped through.

Ø  Thiyyas / Level Pad for the same shall be given by operation engineer, Brick bat shall be laid accordingly.

Ø  Brick bat each layer will be cured for minimum 3 days

Ø  Post Curing, remaining 1/3rd height filling of brick bat and 20mm thick cement mortar screed / cement mortar plaster shall be provided in a single layer.

Ø  Sand mortar in the proportion 1:4 with waterproofing compound (as per mix ratio)

Ø  Top coat shall be of neat cement slurry of adequate consistency and shall be monolithic with brick bat.

Ø  Waterproofing plaster shall be extended upto 500 mm (from RCC slab Top) on vertical surface/ parapet wall.

Ø  Average thickness of brick bat coba shall be maintained as per project specification.

Ø  Top level shall be maintained as per drawing & slope.

Ø  Pond Curing shall be done for 7days and leakage shall be checked.