Single component, moisture cured, liquid Silicone roof coating, which cures to form a strong, highly elastic, impermeable and a monolithic membrane. LASTOFLEX ST creates a shield, which is not only suited for ponding water, but it also acts as cool roof coating by reflecting sunlight.
LASTOLFEX ST holds ETAG 25 years life expectancy certification.
Physical Properties and Advantages
• Easy to apply by brush, roller, or airless spray.
• Long-lasting waterproofing and ideally suited for ponding water.
• It can be applied in a single thick layer without forming bubbles or cracks
• Forms a seamless monolithic membrane, which is 100% bonded to the substrate. Even when damaged, water does not spread to the entire surface of the substrate, and the membrane can easily be repaired locally.
• Excellent resistance to weather conditions: rainwater, frost, UV rays.
• Excellent elastic properties even at very low temperature (-40 OC). Excellent crack-bridging properties.
• Excellent thermal resistance. The membrane does not turn soft or tacky at high temperatures (+80 OC).
• Excellent adhesion on several substrates without use of primer. Special primers are available to cover almost all type of substrates.
• Water vapor permeable. Does not cause moisture accumulation on ceiling. • Good resistance to chemicals and detergents.
• High reflection of solar energy (only in white color) and significant reduction of the temperature inside the building during summer.
• Does not release any dangerous substances once fully cured. It does not contain isocyanates. • Non-flammable & Non–Imo classified product with zero chalking & cost effective
Classification According to Etag 005
• Minimum expected working life: W3 (25 years).
• Climatic zone: S (Severe Climate).
• User Load: P4 (Special).
• Roof slopes: S1 to S4. • Minimum surface temperature: TL4 (-30 OC).
• Maximum surface temperature: TH3 (+80 OC).
• Reaction to Fire (EN 13501-1): Class E
• Dynamic viscosity EN ISO 3219 (23 oC, shear rate 100 [1/s]) : 2350 mPa.s
• Density DIN EN ISO 2811-1 (21 OC) : 1,24 gr/cm3
• Temperature variations resistance : -40 to 90 oC.
• Surface membrane formation time (23 oC, 50% R.H.): 2,5 hours
• Elongation at break point (DIN 53504) : 350%
• Tensile strength (DIN 53504) : 2,20 N/mm2
• Hardness SHORE A (DIN 53505) : 55
• Water Vapor permeability (DIN EN 1931, 23 OC / 75% R.H.) : 12,7 gr/m2/day • Impermeability to water (DIN EN 1928, 1m water column, 24h) : Watertight
• Adhesion on concrete (with primer) : > 2 N/mm2
• Accelerated Weathering Test, UV & water exposure, EOTA TR-010, Radiant exposure 1000 MJ/m2, 4000 hours : Passed, No significant changes
• Resistance against thermal ageing, EOTA TR-011, 200 days at 80 OC : Passed, No significant changes
• Fatigue resistance, EOTA TR-008, -10 OC, initial crack : 1 mm, change in crack width : 1 mm, Number of cycles : 1000 : No crack
LASTOFLEX-ST is applied by roller, brush, or air gun even in a single layer up to consumption of 1,6 lt /m². For improved mechanical and crack-bridging properties, it is recommended to apply LASTOFLEX-ST together with ELASTOTET GEOTEXTILE (non-woven and needle-punched polyester geotextile of 120 gr/m2).
The geotextile is applied on top of the freshly laid first coat of LASTOFLEX-ST, before the application of the second and the third layer.
The use of LASTOFLEX-ST together with geotextile is highly recommended for sealing the areas of joints and cracks, as well as the corners between the floor and the wall or any other extrusions such as chimneys, bases of solar panels, upstands etc.
Furthermore, the use of LASTOFLEX-ST in combination with geotextiles is also recommended for waterproofing roofs with cementitious screeds which have the tendency to crack. Time interval between each coat is at least 3 h and not more than 48 h.
When primer is applied, the first coat of LASTOFLEX- ST can be applied not earlier than 1 hour and not later than 48 hours from the application of the primer.
The drying time is significantly affected by the environmental conditions (temperature and humidity).
Only for application by airless spray, it is suggested to dilute the product with the nonflammable SOLVENT D 40 up to 10%. Never dilute the product with water.
The same solvent can be used for cleaning the tools or the equipment from the fresh coating.
Once the material is cured, it can only be removed mechanically. LASTOFLEX-ST is not suitable for application as a directly exposed layer on swimming pools.
LASTOFLEX-ST is 100% UV stable and color stable and it can be applied on top of LASTOFLEX-PU to eliminate the chalking effect and to provide color stability, especially in dark colors such as red, black, brown, or blue.
To make walkways or to reduce slip, the coating can be sprinkled on top with an appropriate particle size of quartz while it is still wet.
Consumption: A minimum consumption of 1,1 - 1,3 Lt/m2 (1,3 – 1,6 kg/m2) is recommended. In any case, the consumption depends on the roughness of the surface or the specifications of the application.