Alpha Decoupling Membrane 1m x 5m – Double Fleeced

The Double Fleeced Decoupling Membrane (1m x 5m) is a 3–4mm tile underlay that prevents cracked tiles caused by substrate movement, shrinkage and expansion.

It's built for residential and commercial tiling work across Ireland, where substrate movement from temperature swings, screed shrinkage and building settlement is one of the main causes of cracked grout lines and failed floors. The membrane is manufactured from polypropylene with fleece backing on both sides, which gives it strong bond strength with tile adhesive and enough flexibility to absorb lateral stress without transferring it up into the tiled surface. It can be installed over concrete, sand and cement screed, timber floors, and mixed or problem substrates where a single-sided membrane would struggle.

The membrane is fully compatible with underfloor heating systems and holds up well in high-traffic areas, where sustained loading and repeated flexing test a decoupling layer over time. Once joints are sealed with compatible waterproof tape, it also functions as a waterproofing layer, which makes it suitable for wet rooms, bathrooms, kitchens and any tiled area exposed to regular moisture.

Double-fleece construction performs better than single-sided membranes on timber floors, mixed substrates, existing tiled floors, refurbishment projects and slightly uneven screeds, since the fleece on both faces is more forgiving of substrate irregularities during installation. It also tests stronger under point load resistance and rolling load conditions, which is why it's specified for retail, office and other public traffic areas as well as domestic bathrooms and kitchens.

Key specifications:

• Roll size: 1m x 5m
• Thickness: approx. 3–4mm
• Material: polypropylene with double fleece backing
• Temperature resistance: -40°C to +80°C
• Water tightness: pass – 2 kPa (EN 1928)
• Load classification: extra heavy (ASTM C627 – TCNA tested)
• Reaction to fire: Class A1
• CE certified

It suits floor tiling in homes and commercial buildings, concrete and sand/cement screed floors, timber and mixed substrates, underfloor heating installations, wet rooms, bathrooms and kitchens, renovation projects laid over existing tiles, and retail, office, industrial and public spaces.

Installation guide:

• Ensure the substrate is clean, dry and level
• Apply cement-based tile adhesive with a 4–6mm notched trowel
• Lay the membrane fleece-side down into the adhesive and press firmly to remove air pockets
• Butt sheets tightly together and seal joints with waterproof tape where required
• Tile directly over the membrane using a suitable adhesive