Koster NB 4000 25kg Flexible Tanking Render
Koster NB 4000 is a fast an multi-functional polymer modified mineral coating, for waterproofing of building structures inside and outside. This special product combines the properties and advantages of a polymer modified bitumen thick film sealant (PMBC) and a flexible mineral waterproofing slurry into to the same product.
It is resistant to rain soon after application and can be exposed to pressurized water after 24 hours. It is viscoplastic and crack bridging. Koster NB 4000 is free of bitumen, UV stable, radon proof and can be used for adhering insulation boards.
Koster NB 4000 sets quickly even at temperatures of + 2°C and is compatible with old bitumen thick coatings. Insulation boards can be adhered after 4 hours and excavations can be filled after 16 hours.
It can be applied to slightly moist substrates, can be painted and stuccoed over with foundation base plasters. Koster NB 4000 can be filled with kiln-dried quartz sand to create fillets and fill surface roughness.
The addition of the Koster NB 4000 Spray Additive improves the processing properties in terms of sprayability and application with a brush.
- Bitumen and solvent-free material
- Very fast curing even at very low temperatures (from + 2 °C)
- Very early rain proof (2h)
- Compatible with old bituminous or mineral waterproofing systems
- Can be applied as a mortar, sprayed, rolled and brushed
- Applicable on dry or slightly damp surfaces
- Paintable and coatable with foundation renders and façade plasters
- Crack bridging up to 3.5 mm
- Insulation boards can be installed after approx. 4 h
- Usable on horizontal or vertical surfaces
- Resistant to pressurized water after 24 hours
- UV resistant/ stable
- Can be used under cement screeds
- Can be used under tiles on wet rooms
- Slightly vapour permeable
Fields of Application:
- Waterproofing of numerous building structures inside and outside always from the positive side
- Multi-purpose waterproofing material for restoration of buildings
- For repair and restoration of old bituminous or mineral waterproofing layers
- For quick-dry waterproofing requirements, especially on temperatures from 2°C to 20°C
- Waterproofing under ceramic tiles in indoor and outdoor areas according to loading class W4-E
- Horizontal barrier under masonry walls / used as DPC system
- Used as Polymer Modified Sealing Slurry
- For the adhesion of insulation boards on retaining walls from the positive side
- Repair product used to make a scratch coat or fillet mortar by filling it with kiln dried silica sand
Koster NB 4000 is applied in 2 coats by trowel or sprayed with the Koster peristaltic pump, max. hose length 10 m. In addition to the Koster Peristaltic Pump, the “BMP 7” screw pump from b&m can also be used operating with 230 V; Hose 10 m, 3/4 “; nozzle 6.5 mm; 1st gear speed, 10% speed.
The second coat is to be applied as soon as can be done so without damaging the first coat. The layers must be free of defects, even and in the recommended layer thickness. The actual dry layer thickness must not be less than the recommended minimum and must not exceed it by more than 100 %.
Areas prone to or in danger of cracking should have Koster Glass Fibre Mesh imbedded in the fresh first layer. The area waterproofing of the wall must be overlapped at least 10 cm onto the front of the floor slab or the foundation. The external waterproofing must be connected to the existing horizontal waterproofing in all areas. Protect the fresh coating from rain and frost, from exposure to water, as well as strong sunlight until the coating has fully cured.
The Koster NB 4000 formulation has been specifically optimized for cooler, damp weather, for fast rain resistance, and early curing. In dry, sunny, windy and warm climates, the surface may quickly form a skin. In these cases, the material should be smoothed as soon as it is applied and should not be reworked. Do not add water. If a longer pot life is desired, such as when working in warm or sunny conditions, a retarding agent can be provided by Koster upon request. By adding the Koster NB 4000 Spray Additive, skin formation is reduced in summer temperatures and the processing time is extended. Provide a mechanical protection (for example Koster SD Protection and Drainage Sheet) before backfilling.
Approx. 2.4 – 4.8 kg/m² (10.4m² – 5.2m² per 25kg, Refer to consumption tables on the data sheet)