BK-2K

Polymer-modified, bitumen-rubber based, two-component waterproofing material

A polymer-modified bitumen-rubber based, two-component, highly elastic, thick-layer waterproofing coating material. Bonding perfectly to the surface it is applied on, it forms a flexible layer resistant to water and damp, with crack-covering ability. Complies with the DIN 18195 and TS EN 1581 standards.

Areas of Use

• In the waterproofing of building foundations
• In the insulation of shear walls and retaining walls
• In the waterproofing of underground car-park slabs
• In the waterproofing of wet areas
• In the repair of old waterproofing such as bituminous membranes, pitch, asphalt and tar paper
• Used below and above ground, horizontally and vertically.

Advantages

• Comfortable, fast-application consistency.
• Can be applied to all mineral surfaces.
• Forms a seamless, monolithic waterproofing layer.
• Excellent adhesion to the surface.
• Environmentally friendly content, solvent-free and asbestos-fibre-free.
• Its flexible structure bridges shrinkage cracks.
• High freeze-thaw resistance.
• Can be used on dry and damp surfaces.

Consumption

Areas exposed to ground moisture (non-accumulating ground water): min. application thickness (dry film) 2 mm, min. consumption 3 kg/m². Waterproofing against temporarily pressing water: min. application thickness (dry film) 3 mm (with glass-fibre reinforcement mesh), min. consumption 4.5 kg/m². Areas exposed to permanently pressing water (groundwater): min. application thickness (dry film) 4 mm (with glass-fibre reinforcement mesh), min. consumption 6 kg/m².

Shelf Life

Can be stored for 12 months in its unopened original packaging in dry environments at temperatures between 5°C and 25°C. Opened packages must be used immediately.

Application

The application surfaces may be dry or slightly damp. Do not apply to wet or frozen surfaces. Do not apply in areas where water or water-vapour pressure from the negative side, or salt efflorescence, is observed. Surfaces must be clean, sound, load-bearing and free of loose particles. Layers that reduce adhesion, such as oil, grease, dirt, paint, cement laitance, rust, form oil and salt efflorescence, must be completely removed before application. Very glossy and smooth surfaces may need to be roughened before application. Wall-floor junctions should be rounded into a fillet with structural repair mortar 24 hours before application. As a primer, the BK-2K liquid (without mixing in the powder component) is applied thinned with water; for this purpose 10 kg of water and 1 kg of the liquid component must be mixed intensively with a power mixer. The resulting fluid is worked into the surfaces with a stiff brush as a primer and left to dry completely. BK-2K is two-component: the powder component and the liquid component are mixed together before application; no additional water may be added. Mixing must always be done with a low-speed mixer and a special mixing paddle. The mixing process yields a homogeneous, lump-free mixture. Once the primed surface has dried, the main coats are applied. Apply a minimum of 2 coats; if applying by brush, the coats should be applied perpendicular to each other. The application and surface temperature must be between +5°C and +30°C. The finished application must be protected from severe weather for at least 24 hours. After the material has dried completely and before backfilling, it must be protected from impacts during backfill by drainage boards and thermal-insulation boards. Application tools: roller or brush.

Technical Properties

Component A	Polymer-modified bitumen rubber
Component B	Cement-based powder component
Colour	Brown, black when dry
Density (A / A+B)	1,04 kg/l / 1,13 kg/l
Solids content (A / A+B)	58 % / 68 %
Application temperature	+5°C 35°C
Service temperature	-20°C 80°C
Mixing ratio (A/B)	22+8
Curing time	3 hours
Pot life	2 hours
Full drying	2-5 days
Watertightness (EN 15820)	W1 (duration: 24 h, pressure: 0.075 bar, dry film thickness ≥ 3 mm, without mesh)
Crack bridging (EN 15812)	CB1 (bridged crack: ≥ 2 mm)
Flexibility at low temperature (EN 15813)	Pass (duration: 1 h, temperature: 0°C, method: bending in 3 s)
Dimensional stability at high temperature (EN 15818)	Pass (duration: 2 h, temperature: 70°C)
Water resistance (EN 15817)	Pass (28 days immersion in water)
Rain resistance (EN 15816)	R2 (rain test performed 8 hours after application)
Reduction in layer thickness (EN 15819)	Pass (must be less than 50%)
Fire class (EN 13501-1)	Euroclass E