Ceresit CT85 Flex Adhesive & Base Coat 25kg | EPS

Description

Ceresit CT85 Flex is a fibre-reinforced adhesive and base coat mortar for EPS boards within the Ceresit Ceretherm system. It both bonds the boards and forms the mesh-reinforced layer over them. The Fibre Force fibre blend is what separates it from a standard adhesive: it spreads stress through the cured layer, so the basecoat handles thermal movement and impact without hairline cracking.

Coverage

• Fixing EPS boards: approximately 5.0kg/m²
• Armoured (mesh) layer: approximately 4.0kg/m²
• Putty layer: approximately 1.0kg/m²

Mixing and application

• 6.5 to 7.0 litres of clean water per 25kg bag, mixed with a low speed drill
• Pot life approximately 2 hours
• Bond boards perimeter and dab, at least 40% coverage, then mechanically fix
• Rasp boards flat, apply 3-4mm and bed alkali-resistant mesh into the wet mortar
• Prime with CT16 before the top coat
• Prime absorbent substrates such as aerated concrete with CT17, 2 hours minimum drying
• Check adhesion first by bonding 100 x 100mm EPS offcuts in a few places and pulling them off after 4-7 days

Specification

• Compressive strength: 18 N/mm² (CS IV)
• Water absorption after 24h: < 0.5 kg/m² to ETAG 004
• Fire classification: B-s1 to EN 13501-1
• Bulk density: approximately 1.3 kg/dm³
• Suitable for trowel or machine application
• Shelf life 12 months, stored dry on pallets in original packaging

CT85 or ZU?

Both bond EPS and take the mesh. CT85 Flex is the higher specification of the two, with the added fibre reinforcement for impact and crack resistance — worth it on exposed elevations, at ground level where knocks happen, and anywhere with movement to accommodate. ZU is the standard option in the Ceretherm Popular system and is the more economical choice on straightforward work. Call us if you want a view on which suits the job.

Doing a full elevation? See the CT85 pallet deal.