All static cracks wider than 1 mm. in the substrate must be opened up to 12 mm X 12 mm. and treated with a mix of cement/sand mix with Koster S B Bonding emulsion and water at least 24 hours to application.

Fillets:
Similarly at all the junctions of the parapet wall and the slab, the fillets must be built up with a mix of cement/sand/quartz sand mix with Koster S B Bonding emulsion and water at least 24 hours prior to the application.

Down take / Pipe Insertions:
Pipe inserts must be installed prior to the application of the Koster NB\Koster NB Elastic waterproofing system. At the opening in the slab around the pipe the substrate should be similarly opened up by cutting back around the pipes to give sufficient depth and cleaned thoroughly. This must be then built up with a mix of cement/sand mix with Koster S B Bonding emulsion and water at least 24 hours prior to application. .

Construction Joints:
Finally dampen all the surface areas thoroughly with clean water, as this is necessary prior to the application of the Koster NB system. The dampness in the substrate will ensure that the chemical reaction between the Koster NB system and the chemicals in the concrete substrate takes place completely. However the application of the Koster NB system should not be made over standing or running water.

MIXING AND APPLICATION:

Materials:
Koster NB cement based crystalline based waterproofing system
Koster NB Elastic cement based crystalline based waterproofing system
SB Bonding Emulsion liquid
Water
Brushes

Mixing:
To one bag of Koster NB I (25 kg), add 7 - 8 liters of water premixed with 10 % SB Bonding Emulsion. Mix thoroughly to a slurry consistency. The system is now ready for application.
The powder and the liquid components of the Koster NB Elastic system must be mixed together. Mix thoroughly to a slurry consistency. The system is now ready for application.

Application:
The Koster NB system is brush applied, on to the already damped surface. The brush on is done in 2 coats. . The coverage is 0.60 kg per sq. meter per coat and each coat is done perpendicular to each other. After the 1st coat there should be a gap of 12 – 24 hours before the 2nd coat is applied. Prior to the 2nd coat application the 1st coat surface should be dampened thoroughly to ensure that the chemical reaction is complete. No water curing is required. The finished surface should be left exposed for 48 hours for positive side treatment and 4 days for negative side after which further build up works can be carried out.

For treatment on Bathrooms it is recommended that the treatment extend upto the shower spout level in the shower areas and extend 1.00 mt from the base in the other areas. This will ensure that all the weak points are covered completely and the surface is completely watertight. The vertical termination height for the kitchen and AHU’s will be finalized as per site requirements.

For the fillets, downtakes and all the pipe insertions the Koster NB Elastic system should be applied along the length, right around and onto the pipe section to make it completely watertight. The elastic properties of the Koster NB elastic system will eliminate the possibilities of cracks developing at these junctions. The Koster NB system has excellent adhesion properties to metal surfaces as well and also has anti corrosive properties.

The area along the construction joints will be treated with Koster NB Elastic after opening the joints in a ‘v’ notch & applying bond coat. Then after it becomes tacky filling the crack with Polymer mortar & leveling the surface. Koster NB Elastic system should be applied in a single coat over the joint in 150mm width over two coats of Koster NB System to make it completely watertight. The Koster NB elastic properties of the system will eliminate the possibilities of cracks developing at these joints.

Testing:
Make a watta around the periphery of the Waterproofed area . Pond the entire area with water and keep the area under observation for 48 hrs.

Down takes :
A PVC pipe, with ring, of suitable diameter will be inserted into the downtake so that the mouth of the downtake pipe is totally sealed. Water will be filled and the area pounded for 48 hours.

Note: All de-watering will be done with the help of tullu pump and built up watas will be carefully cut and the area will be cleaned.

Failure:
Incase of failure, the area will be redone with single coat over the existing waterproofing system and the pond test will be carried out once again. Incase of failure resulting from crack in the wata, the entire section of the wata along the length will be cut open and redone. After 24 hours the waterproofing system will be reapplied overlapping the existing waterproofing by 150 mm on either side. Pond test will be carried out again.

Limitation:
The Koster NB system cannot be applied on running or standing water.
The Koster NB system must be protected from acid or sulphurous attack in concentrations exceeding that in Portland Cement Type I/II
The Koster NB system once installed must be protected from damage by other agencies working in the installed area.

Protective cement screed:
Laying 20 mm (ave. thickness) cement sand screed (1:5) around the area for protection of waterproofing system on slab area and 12-15mm around the wall area. Curing of the screed will be done for 7 days.

Materials:
Cement 43 Grade
Sand Mahad variety or equivalent (silt content Max. 5%)
Water Clean and free of deleterious substances.

Consumption:
Screed:
Cement: 5.0 kg per sq. m.

Wata – 25 mm X 25 mm
Cements 5.0 kg per 30.50 mtrs running length