SILCOR 575 LB is a one-part, high-solids, semi self-levelling polyurethane waterproofing membrane for horizontal surfaces set to falls. It forms a flexible Class III waterproof barrier in suitable internal and external applications.
Use 575 LB on balconies, podiums, roof decks, landscaped areas and plant-room floors, or beneath screeds in bathrooms and laundries. It flows out on horizontal surfaces and needs the correct primer, joint detailing and protective finish.
Where the finished membrane remains exposed, the specified SILCOR Top Coat 75 system provides UV protection and a light foot-traffic finish. SILCOR 575 LB is not designed for heavy foot or vehicle traffic. For those demanding applications, compare SILCOR 580 with its specified wear-coat and Top Coat 80 system.
What film thickness is needed for SILCOR 575 LB?
Use the project-specified thickness. GCP provides 1.3 mm and 1.5 mm systems with different rates and coat requirements.
When can I flood test the membrane?
Allow approximately 48 hours at 23°C and 60% relative humidity before flood testing or topping.
How flexible is SILCOR 575 LB?
Elongation exceeds 900% to AS 4858 and 800% to AS 4654.1. Both results achieve Class III.
Can SILCOR 575 LB be left exposed?
Only in an approved exposed system with SILCOR Top Coat 75 for UV protection and light foot traffic.
| Property | Value |
|---|---|
| Base Chemistry | High solids, moisture curing polyurethane |
| Water Vapour Transmission | 4.87 g/m²/24h |
| Tensile Strength | > 4.5 MPa (AS 4858), > 5.0 MPa (AS 4654.1) |
| Elongation | > 900 % (AS 4858), > 800 % (AS 4654.1) |
| Bond Strength | >48 N (AS 4654.1) |
| Shelf Life | 9 months |
| Specific Gravity | 1.40 g/mL |
| Viscosity | 7,000 MPa.s |
| Solid Content | 91 %w/w |
| VOC Content | <110 g/L |
| Tack Free Time | 4 h |
| Set Time | 6 h |
| Min Recoat Time (23°C/60% RH) | 12 h |
| Max Recoat Time (23°C/60% RH) | 48 h |
| Min Through Cure Time (23°C/60% RH) | 48 h |
| Rain Resistant Min Cure (23°C/60% RH) | 2 h |
| Ready for Flood Testing/Topping (23°C/60% RH) | 48 h |
| Shore A Hardness | > 65 °A |
| Classification | Class III High Extensibility (AS 4858-2004, AS 4654.1-2012) |
| Movement Capability | Pass (No fatigue cracking exhibited) |
| Water Resistance | Pass |
| Chemical Resistance | Pass |
| Resistance to Detergent Immersion | Pass |
| Heat Aging | Pass |
| Application Temperature Range (Substrate/Ambient) | +5°C to +35°C |
| Application Relative Humidity Range | 35% to 85% |
| Minimum Dry Film Thickness (Specified System) | 1.3 mm or 1.5 mm DFT; different system rates and film builds apply |
Here are some common examples on where SILCOR® 575 LB used by our customers.
