Sikalastic®-851 R
Sikalastic®-851 R is a two component, elastic, crack-bridging, rapid-curing modified polyurethane/ polyurea-hybrid membrane. Sikalastic®-851 R is for machine application only. Suitable for use in hot and tropical climatic conditions.
- Solvent free
- Fast application: application with 2-part hot spray equipment
- Fast curing: over coating with top coat possible after approximately 10 minutes
- Seamless waterproofing membrane
- High Solids: contains no fillers
- Excellent crack-bridging properties
- Highly elastic and crack bridging
- Low viscosity
- Water vapour permeable allows the substrate to breathe
- Good adhesion to most substrates
- 12 months shelf life
Usage
- For use as a waterproofing membrane on flat and pitched roof structures with additional top coat for UV-protection for exposed roofs.
- For use as a waterproofing membrane underneath planting or hard landscaping on podium areas.
- For use as a waterproofing membrane underneath XPS insulation as part of an inverted or vegetative roof system.
- For use as a waterproofing membrane for other concrete structures and on non-trafficked concrete areas with an additional top coat for UV-protection.
Advantages
- Solvent free
- Fast application: application with 2-part hot spray equipment
- Fast curing: over coating with top coat possible after approximately 10 minutes
- Seamless waterproofing membrane
- High Solids: contains no fillers
- Excellent crack-bridging properties
- Highly elastic and crack bridging
- Low viscosity
- Water vapour permeable allows the substrate to breathe
- Good adhesion to most substrates
- 12 months shelf life
Packaging
| Component A | 211 kg drum |
| Component B | 202 kg drum |
Colour
| Component A (ISO) | Clear / brownish |
| Component B (Resin) | Grey or yellowish |
Mixed product: grey approximately RAL 7004
Product Details
SUSTAINABILITY
Conformity with LEED v 2009 IEQc 4.2: Low-Emitting
Materials - Paints and Coatings
APPROVALS / CERTIFICATES
- Test report for root resistance following DIN 4062: report no.: P9638-1-E dated 29/05/2015
- Test report for crack bridging properties following DIN EN 1062-7: report no.: P 9638-2-E dated 29/05/2015
Composition
Modified Polyurethane / Polyurea-Hybrid
Shelf life
| Component A | 12 months from date of production |
| Component B | 12 months from date of production |
Storage conditions
The product must be stored properly in original, unopened and undamaged sealed packaging in dry conditions at temperatures between +5 °C and +30 °C.
Higher storage temperatures may reduce shelf life of product.
Reference shall also be made to the storage recommendations within the safety data sheet.
Density
| Component A | ~1.08 kg/l |
| Component B | ~1.04 kg/l |
| Mixed resin: | ~1.00 kg/l (cured film) |
All density values at +23 °C
Solid content
> 99 %
Viscosity
| Component A | ~2300 mPas at +20 °C |
| Component B | ~2300 mPas at +20 °C |
System Structure
Exposed Roof Waterproofing
Sikalastic®-851 R is applied in one coat and sealed with one coat Sikalastic®-621 or Sikalastic®-445
| Layer | Product | Consumption |
| 1. Primer | Please refer to substrate pre-treatment | Please refer to PDS of the primer |
| 2. Waterproofing | Sikalastic®-851 R | ≥ 1.6 kg/m2 |
| 3. UV Protection | Sikalastic®-621 or Sikalastic®-445 | ≥ 1.0 kg/m2 |
Non-Exposed Roof Waterproofing
Sikalastic®-851 R is applied in one or two coats
| Layer | Product | Consumption |
| 1. Primer | Please refer to substrate pre-treatment | Please refer to PDS of the primer |
| 2. Waterproofing | Sikalastic®-851 R | ≥ 2.1 kg/m2 |
Note: These figures are theoretical and do not include for any additional material required due to surface porosity, surface profile, variations in level and wastage.
Shore A Hardness
| Temperature | After 1 hour | After 24 hours | After 28 days |
+8 °C | ~81 | ~88 | ~88 |
+23 °C | ~83 | ~88 | ~88 |
Tensile Strength
| ~11.0 N/mm2 (28 d / +23 °C) | (DIN 53504) |
Crack Bridging Ability
| Dynamic crack-bridging class | B 4.2 |
| Static crack-bridging class | A 5 |
Resistance to Root Penetration
| Free of penetration of the roots Free of growth into the ground | (DIN 4062) |
Reaction to Fire
| Euroclass E | (EN 13501-1; DIN EN ISO 11925-2) |
Chemical Resistance
Sikalastic®-851 R is generally resistant to:
- Bitumen
- Alkalis
Temperature Resistance
Sikalastic®-851 R is short term resistant to mastic asphalt (hot poured asphalt) applied at a maximum of +240 °C.
Sikalastic®-851 R elastic properties are maintained at temperatures as low as -30 °C.
Dry film thickness
Exposed Roof Waterproofing
| Waterproofing | ~1.6 mm |
| UV Protection | ~0.5 mm |
| Total | ~2.0 mm |
Non-Exposed Roof Waterproofing
| Waterproofing | ~2.1 mm |
Application
Mixing Ratio
Component A : Component B = 1 : 1 (by volume)
Component A : Component B = 1.04 : 1 (by weight)
Product Temperature
| Component A | +70 - 80 °C |
| Component B | +65 - 70 °C |
| Hose | +65 - 70 °C |
Ambient Air Temperature
+8 °C min. / +50 °C max.
Relative Air Humidity
80 % r.h. max.
Substrate Temperature
+8 °C min. / +55 °C max.
≥ 3 °C above dew point
Substrate Moisture Content
≤ 4 % pbw moisture content.
Test method: Sika®-Tramex meter, CM - measurement on Oven-dry method
No rising moisture according to ASTM (Polyethylene-sheet).
Substrate Pre-Treatment
| Substrate | Primer |
| Cementitious substrates | Sika® Concrete Primer or Sikafloor®-161 lightly broadcast with quartz sand, 0.3 – 0.8 mm, for example Sikadur®-507 |
| Ceramic tiles (unglazed), and concrete slabs | Sika® Concrete Primer |
| Bituminous felt | Sikalastic® Metal Primer |
| Bituminous coatings | Sikalastic® Metal Primer |
| Metals Ferrous or galvanised metals, lead, copper,aluminium, brass or stainless steel | Sikalastic® Metal Primer |
For the consumption rates and waiting time / overcoating please refer to the PDS of the appropriate primer. Other substrates must be tested for their compatibility. If in doubt, apply a test area first.
Waiting Time / Overcoating
Before applying Sikalastic®-851 R on Sikafloor®-161 allow:
| Substrate temperature | Minimum waiting time | Maximum waiting time1 |
| +10 °C | 24 h | 1 month |
| +20 °C | 12 h | 1 month |
| +30 °C | 8 h | 1 month |
| +45 °C | 6 h | 1 month |
Before applying Sikalastic®-851 R on Sikalastic®-851 R allow:
| Substrate temperature | Minimum waiting time | Maximum waiting time2 |
| +10 °C | 4 min | 3 h |
| +20 °C | 4 min | 3 h |
| +30 °C | 4 min | 1 h |
| +45 °C | 4 min | 1 h |
Before applying Sikalastic®-621 or Sikalastic®-445 on Sikalastic®-851 R allow:
| Substrate temperature | Minimum waiting time | Maximum waiting time2 |
| +10 °C | 4 min | 24 h |
| +20 °C | 4 min | 24 h |
| +30 °C | 4 min | 24 h |
| +45 °C | 4 min | 24 h |
1 Assuming that any dirt has been carefully removed and any contamination is avoided.
2 If the maximum waiting time is exceeded, Sika® Concrete Primer has to be applied with a consumption rate of 100 g/m2 as an adhesion promoter between the layers.
Note: Times are approximate and will be affected by changing ambient conditions particularly temperature and relative humidity.
Applied Product Ready for Use
| Rain resistant after | Ready for foot traffic1 (careful) | Ready for foot traffic | Ambient conditions |
| ~5 min | ~8 min | ~24 h | +10 °C |
| ~5 min | ~5 min | ~18 h | +20 °C |
| ~5 min | ~4 min | ~14 h | +30 °C |
| ~5 min | ~4 min | ~12 h | +45 °C |
1Only for inspection or for application of next layer.
Note: Times are approximate and will be affected by changing ambient conditions particularly temperature and relative humidity.
SUBSTRATE PREPARATION
The surface must be sound, of sufficient strength, clean, dry and free of dirt, oil, grease and other contamination. Depending on the material the substrate must be primed or mechanically cleaned. Grinding may be necessary to level the surface. Suitable substrates are such as: Concrete, bituminous felts and coatings, metal, brickwork, asbestos cement, ceramic tiles.
For detailed information regarding substrate preparation and primer chart please refer to Method Statement.
MIXING
Dose and mix with suitable two-component spray equipment. Maintain recommended product and hose temperature.
Recomended pressure:
Component A + B 160 - 180 bar.
Ensure equal pressure of component A + B. The accuracy of pressure, mixing and dosage must be controlled regularly with the equipment.
APPLICATION
Prior the application of Sikalastic®-851 R the priming coat if used must have cured tack-free. For the Waiting Time / Overcoating please refer to the Product Data Sheet of the appropriate primer. Damageable areas (handrails etc.) have to be protected with tape or plastic wrapping.
Waterproofing: Spray apply Sikalastic®-851 R with suitable two-component hot spray equipment. Possible suppliers of spray equipment are Gama, Graco, Isotherm, WiWa, Reaku etc.
UV Protection: One layer of Sikalastic®-621 or Sikalastic®-445 applied either by roller or airless spray.
For more detailed application engineering information please refer to the appropriate Method Statement.
CLEANING OF EQUIPMENT
Clean all tools and application equipment with Thinner C immediately after use. Hardened and/or cured material can only be removed mechanically.