SikaRoof® PUR-20 UV
High performance, UV-stable spray applied hybrid polyurethane roof waterproofing system
SikaRoof® PUR-20 UV is a spray applied, seamless, highly elastic and UV-stable hybrid polyurethane roof waterproofing system consisting of Sikalastic®- 888 Hybrid and Sikalastic®-701. Suitable for use in hot and tropical climatic conditions.
- Fast applied system- 1 to 2 days for total application
- Two component top coat- easy to apply with very low opacity
- UV stable - Aliphatic top coat has good resistance to yellowing
- Resistant to long term ponding water
- Easily recoated – no stripping required
- Cold applied - requires no heat or flame
- Seamless roof waterproofing membrane - easy to detail
- Fast curing - free from resin damage almost immediately on application
- High elastic and crack-bridging - retains flexibility even at low temperatures
- Good adhesion to most substrates - refer to product method statement
- Vapour permeable - allows substrate to breathe
- Strong resistance to common atmospheric chemicals
System Structure
Usage
SikaRoof® PUR-20 UV may only be used by experienced professionals. SikaRoof® PUR-20 UV can be used as following:- Roof waterproofing solution for new construction and refurbishment projects
- For roofs displaying complex detail areas and geometry, even when accessibility is limited
- For cost efficient life cycle extension of failing roofs
Advantages
- Fast applied system- 1 to 2 days for total application
- Two component top coat- easy to apply with very low opacity
- UV stable - Aliphatic top coat has good resistance to yellowing
- Resistant to long term ponding water
- Easily recoated – no stripping required
- Cold applied - requires no heat or flame
- Seamless roof waterproofing membrane - easy to detail
- Fast curing - free from resin damage almost immediately on application
- High elastic and crack-bridging - retains flexibility even at low temperatures
- Good adhesion to most substrates - refer to product method statement
- Vapour permeable - allows substrate to breathe
- Strong resistance to common atmospheric chemicals
Colour
Sikalastic®-888 Hybrid: Light Grey
Sikalastic®-701: Light Grey (RAL 7035)
White (RAL 9016)
System Details
APPROVALS / CERTIFICATES
AS 4654.1-2012: Sikalastic® 888 Hybrid (base coat membrane)
AS 4654.1-2012: Sikalastic® 701 (top coat membrane)
ASTM D7896- Solar reflective index/ Thermal emmitance testing- Sikalastic®-701
System structure
Standard SikaRoof® PUR-20 UV application without non-slip addition:
| Layer | Product | Required DFT |
| 1. Primer | Sikalastic® Moisture Seal or Sikalastic® -100 EP Primer | Please refer to PDS of the Primer |
| 2. Base coat | Sikalastic® -888 Hybrid | 2.0mm DFT |
| 3. Top coat | Sikalastic® 701 | 0.22mm DFT |
Standard SikaRoof® PUR-20 UV application without non-slip addition:
| Layer | Product | Required DFT |
| 1. Primer | Sikalastic® Moisture Seal or Sikalastic® -100 EP Primer | Please refer to PDS of the Primer |
| 2. Base coat | Sikalastic® -888 Hybrid | 2.0mm DFT |
| 3. Top coat | Sikalastic® 701 | 0.22mm DFT |
| 3. Aggregate | 20-40 mesh aggregate | 0.5-1kg/m2 |
| 4. Top coat | Sikalastic®- 701 | 0.22mm DFT |
Aggregate:
Aggregate is to applied to the first top coat (Layer 3) immediately after application. Use clean, rounded or semi-angular oven dried quartz sand with a size gradation of 20–40 mesh and a minimum hardness of 6.5 per Moh’s scale for pedestrian traffic. Seeding of aggregate means an even light broadcast short of refusal. A full broadcast of aggregate means a heavy application to refusal. Any loose aggregate must be removed prior to recoating, back roll aggregate where required.
Composition
Sikalastic®-888 Hybrid: Spray applied hybrid polyurethane/polyurea
Sikalastic®-701: 2 component aliphatic hybrid polyurethane
Volatile organic compound (VOC) content
All system components ≤ 250 grams per litre
Compliant with Green Building Council of Australia VOC content requirement
Dry film thickness
Sikalastic®-888 Hybrid: 2.0mm DFT
Sikalastic®-701: 0.22mm DFT
Total system: 2.22mm DFT
Application
Ambient air temperature
+5 °C min. / +35 °C max.
Relative air humidity
5 % r.h. min. / 85 % r.h. max
Substrate temperature
+5 °C min. / +60 °C max.
≥3 °C above dew point
Substrate moisture content
≤4 % pbw moisture content.
Test method: Sika®-Tramex meter
No rising moisture according to ASTM (Polyurethane-sheet)
Waiting time to overcoating
Please refer to individual data sheets of primer, Sikalastic® -888 Hybrid and Sikalastic® -701 for overcoat time frames.
EQUIPMENT
Specialist plural component spray equipment is required to install this system; without experience/training in this equipment you will not be able to install the system.
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 and mechanically cleaned. Grinding may be necessary to level the surface. Suitable substrates are: concrete, metal, brickwork, asbestos cement, ceramic tiles.
APPLICATION
Prior the application of SikaRoof® PUR-20 UV the priming coat must have cured tack-free. For the Waiting Time / Overcoating please refer to the PDS of the appropriate primer. Damageable areas (handrails etc.) have to be protected with tape or plastic wrapping. Please note, always begin with details prior to the installation of the horizontal surface.
1. Spray-apply a coat of Sikalastic®-888 Hybrid. Please refer to the Sikalastic®-888 Hybrid product data sheet for application rates and drying times; 1 coat will be sufficient to acheive the DFT of 2.0mm
2. Apply the top coat of Sikalastic®-701. If a non-slip finish is required, two coats will need be installed with the non-slip finish being broadcast into the first coat of Sikalastic®-701. Once first coat is cured, the coating should be broomed/vacummed of excess material and the subsequent top coat applied within 24 hours.
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.