Variable-Sd vapour retarder for converting roofs from inside or outside 

DELTA®-NOVAFLEXX changes its Sd value with the humidity of the air. The polyamide sheet responds selectively to humidity fluctuations. In extreme cases, the Sd value may drop from its original level of 5m to 0.2m across the entire surface or in certain places. The density of the material changes with the air humidity. As the latter increases, DELTA®-NOVAFLEXX becomes more permeable, and its vapour diffusion resistance declines. The sheet reduces the risk of condensate forming in the construction. For an airtight roof refurbishment, add the DELTA®-MAXX PLUS energy-saver membrane to DELTA®-NOVAFLEXX and you have a complete energy-saving roof.


Overview of the most important advantages

DELTA Allows drying inside
Allows drying inside
DELTA Humidity variable
Humidity variable
Long-term protection against aging
Long-term protection against aging
Made in Germany
DELTA Airtight
DELTA Bico technologie
Made in Germany

Installation of DELTA®-NOVAFLEXX


Thanks to its highly robust and tear-resistant cloth, the installation of DELTA®-NOVAFLEXX is quick, safe, and cost-efficient. The new screen printed surface supports precise and quick installation.


For converting a roof from the inside. 

DELTA®-NOVAFLEXX may be installed either parallel with or across the rafters. Fix it easily and cost-efficiently with staples or clout nails. Overlaps of DELTA®-NOVAFLEXX are sealed with DELTA®-MULTI BAND . The DELTA®-TIXX cartridge adhesive may be used to make airtight connections between the sheet and smooth surfaces in gable walls, interior purlins, chimneys, etc. On rough walls, seams are made with DELTA®-KOM BAND and contact bars or with DELTA®-LIQUIXX .

For re-roofing or converting a roof from outside: 

Remove the roof covering and the old insulation. Cover any nails or screws protruding from the interior lining with an insulation panel. Otherwise, attach DELTA®-NOVAFLEXX directly to the interior lining: roll out along the gutter and across the rafters and fill in the rafter spaces without putting tension on the material. Fix along the rafters with espalier laths. Sheet overlap: 10cm. Seal seams with DELTA®-MULTI BAND or DELTA®-THAN plus espalier laths. Cut insulation to rafter space width (+ 1cm) and put in.

Technical data: DELTA®-NOVAFLEXX

MaterialPolyamide film with laminated special fleece..
ApplicationAir and vapor control layer for pitched roofs, walls and floors
Fire resistanceClass E, EN 13501-1
Tear strengthapprox. 150/130 N/5 cm,
Sd valueapprox. 5.0 m. in a dry environment
approx. 0.2 m in a humidity environment
Service Temperature range-40 °C to +80 °C
Weightapprox. 90 g/m²
Roll weightapprox. 6.8 kg
Roll size50 m x 1,50 m    (40 rolls / pallet)

Accessories for DELTA®-NOVAFLEXX

DELTA Multi Band ico
DELTA Flexx Band ico

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