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Reflective membranes

Alkreflex Roof 1.7

Alkreflex® Roof 1.7 is a multi-layer insulating breather membrane.

1,20 x 10 m Article no. 8413012000


Alkreflex® Roof 1.7 is a multi-layer insulating breather membrane. It is watertight, breathable and insulating, and helps to save space. It is ideal for situations where modifications cannot be made to gutters and roof edges, like in listed buildings or terraced homes. Alkreflex® Roof 1.7 features a core of high-density wool, enclosed within two breathable reflective membranes. The bottom layer uses heat reflection (infrared) to improve the construction’s overall heat resistance. Alkreflex® Roof 1.7 does not feature stitches, which means air and moisture leaks can be avoided. Alkreflex® Roof 1.7 is an efficient and effective insulation solution that wastes very little space.


Alkreflex® Roof 1.7 must be used as a breathable and water-proof layer on the cold side of the construction. The water-proof layer must face outwards. To realise the best possible result, it is recommended to keep the reflective layer at least 20 mm away from the surface. Alkreflex® Roof 1.7 can be used for facade and roof constructions in new-build and renovation activities.


Alkreflex® 1.7 must be applied horizontally and in the same way as roof tiles. Alkreflex® 1.7 features an overlap flap, which ensures effective water run-off without needing a thick structure. Use VAST-R® Non-woven tape to tape across the whole overlap to ensure an air- and watertight finish. The material must be fixed in place between battens. To ensure effective reflection, it is advised to keep an air cavity of at least 20 mm on the reflective aluminium side.




R rating of 1.7m 2 K/W when air layer and contact resistances are used

Requires minimum space

Airtight insulation

Reduces energy consumption


Membrane and insulation – 2-in-1

Membrane flap ensures fast water seal without thick structure


Weight 1040 gr /m²

Fire class F

Water tightness W1

Water vapour resistance Sd 0,068 m

Water vapour transmission 300 g / m² / day

Tensile strength machine direction minimaal 400N / 50 mm

Tensile strength cross direction minimaal 400N / 50 mm

Temprature resistance -20°C / +80°C

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