ST – LASTOFLEX ST Silicone Roof Waterproofing, 25-Year W3
عازل سيليكون ST لعزل السطح مقاوم للشمس

Brand: ELASTOTET (Greece) — LASTOFLEX ST
Silicone liquid roof membrane, 100% UV and colour stable, no chalking
ETAG 005 W3: 25-year working life; single-coat application possible
Consumption 1.0–1.3 L/m²
Packs: 1 Kg, 4 Kg, 18 L · White

Size

Clear

SKU: N/A Categories: Building Materials, ELASTOTET, Waterproofing, Waterproofing Brand: Elastotet

Description
Additional information

ELASTOTET LASTOFLEX ST is a one-component, liquid-applied silicone roof waterproofing made in Greece and supplied in Lebanon by Rousse. It cures with air humidity into a seamless, elastic membrane that is 100% UV and colour stable, does not chalk, and can be applied as a single thick coat on roofs exposed to full sun.

LASTOFLEX ST is classified to ETAG 005 for a minimum working life of 25 years (W3) in severe climates. In white it reflects solar heat and noticeably lowers the temperature of the floor below in summer.

Where to use it

Exposed flat roofs and terraces, as the final waterproofing coat
Roofs insulated with polyurethane foam or polystyrene boards
Vertical and horizontal concrete, cement screeds, old tiles and metal
As a UV-stable top coat over LASTOFLEX PU

How to apply

Surface must be dry (concrete moisture below 5%), sound and free of dust, oil and old coatings. Do not wash with water before applying.
Seal joints and cracks with ELASTOSEAL PU.
Primer is optional; Primer VL strengthens weak concrete and Primer EP-W is used on damp concrete. Tiles and metal need no primer.
Apply by roller, brush or airless spray, in one thick coat or several coats 3 to 48 hours apart, for a total of 1.0–1.3 L/m². Lay ELASTOTET geotextile into the fresh first coat at corners, joints, cracks and cracked screeds.
Never dilute with water. For spraying, thin up to 10% with Solvent D60.

Specifications

Brand	ELASTOTET S.A., Greece
Type	One-component silicone liquid membrane, moisture-curing
Classification	ETAG 005: W3 (25 years), climatic zone S, user load P4, roof slopes S1–S4
Elongation at break	350% (DIN 53504)
Tensile strength	2.2 N/mm² (DIN 53504)
Hardness	Shore A 50
Service temperature	−30 to +80 °C
Watertightness	Watertight, 1 m water column, 24 h (EN 1928)
Consumption	1.0–1.3 L/m² (1.2–1.6 kg/m²)
Curing time	12–24 h
Reaction to fire	Class E (EN 13501-1)
Colour	White
Pack sizes	1 Kg, 4 Kg, 18 L
Shelf life	12 months, sealed, below 25 °C

On special order: LASTOFLEX ST in grey and red, and 0.7 L / 3.6 L cans. Ask us for lead time.

FAQ

What is the difference between LASTOFLEX ST and LASTOFLEX PU?
ST is silicone-based: fully UV and colour stable with zero chalking, ideal as the exposed final coat and possible in one thick layer. PU is polyurethane-based: stronger and more elastic, also used under tiles and in tanks. ST is often used as the top coat over PU.

Can LASTOFLEX ST be used as a UV top coat over polyurethane coatings?
Yes. LASTOFLEX ST works as a UV-resistant top coat over polyurethane waterproofing such as LASTOFLEX PU or LASTOFLEX PB. It shields the PU layer from sunlight, keeps a bright white heat-reflective finish and does not chalk. Apply it once the PU coat has cured and the surface is clean and dry; contact us for the recommended overcoating time on your job.

Can I apply it in one coat?
Yes. LASTOFLEX ST can be applied in a single thick coat up to 1.6 L/m².

Can I tile over LASTOFLEX ST?
It is designed as an exposed roof finish. For waterproofing under tiles, use LASTOFLEX PU or LASTOFLEX PB.

What do people call it in Lebanon?
Usually 3azl stou7 (roof waterproofing), 3azl silicone, or dehen 3azel abyad (white waterproof coating); in Arabic عزل سطوح سيليكون.

Is a liquid membrane better than bitumen rolls?
A liquid membrane bonds 100% to the roof with no seams or overlaps. If it is ever damaged, water cannot travel underneath it, so the leak is easy to find and repair locally. With sheet membranes, leaks are hard to trace and often mean removing the whole membrane.

Who gives the 25-year guarantee?
The W3 classification (ETAG 005) is the tested working life of the material, up to 25 years. The guarantee on a finished roof comes from the applicator, because the result depends on surface preparation and application.

أسئلة شائعة

شو الفرق بين لاستوفلكس ST ولاستوفلكس PU؟
ST أساسه سيليكون: ما بيتأثر بالشمس ولا بيتغيّر لونه ولا بيطبشر، ممتاز كطبقة أخيرة مكشوفة وبينحطّ بطبقة وحدة. PU أساسه بولي يوريثان: أقوى وأمطّ، وبينحطّ كمان تحت البلاط وبالخزانات. كتير مرات بينحطّ ST فوق الـPU.

فيني حطّه بطبقة وحدة؟
إيه، لاستوفلكس ST بينحطّ بطبقة وحدة سميكة لحد 1.6 ليتر بالمتر.

فيني بلّط فوق لاستوفلكس ST؟
هو معمول ليضل مكشوف عالسطح. للعزل تحت البلاط استعمل لاستوفلكس PU أو PB.

العزل السائل أحسن من رولات الزفت؟
العزل السائل بيلزق 100% عالسطح بدون وصلات ولا تراكب. إذا انجرح، المي ما بتمشي تحته، فبتلاقي مكان النش بسهولة وبتصلّحه بمطرحه. مع الرولات، النش صعب يتلاقى وغالباً بيضطرك تقلع العزل كلّه.

مين بيعطي كفالة الـ25 سنة؟
تصنيف W3 (ETAG 005) هو عمر المادة المُختبَر لحد 25 سنة. أما كفالة الشغل المنفَّذ فبيعطيها المعلّم أو المتعهّد يلي نفّذ، لأن النتيجة بتتعلّق بتحضير السطح والتطبيق.

شو اسمه بلبنان؟
عادةً عزل سطوح، عزل سيليكون أو دهان عازل أبيض.

Also known as: silicone roof coating, liquid silicone membrane, cool roof coating, 3azl stou7, 3azl el sate7, 3azl silicone, dehen 3azel, dehen 3azel abyad, mane3 nesh · عزل سطوح، عزل السطح، عازل سيليكون، دهان عازل للسطح، دهان عازل أبيض، مانع نش، عزل مائي للسطح

لاستوفلكس ST من ELASTOTET اليونانية — عازل سيليكون سائل للسطوح المكشوفة، مقاوم للشمس ولا يتغير لونه، يُطبّق بطبقة واحدة، مصنّف لعمر 25 سنة.

Where to buy in Lebanon: ROUSSE Contracting Co. SAL (formerly ROUSSE Trading Co.), exclusive distributor of ELASTOTET in Lebanon. Showroom: Fouad Chehab, Sin el Fil. Phone +961 1 496 734 · WhatsApp +961 71 111 351. Open Monday–Friday, 8:00–16:30.