Metra zero
brevetto patentBreathable and waterproofing underlay
Highly breathable underlay composed by 3 layers in polypropylene welded with ultrasonic technology. The absence of glues and harmful substances makes the product totally recyclable with high breathable properties. Stabilized against UV rays. It has anti-skid properties.
Placed in direct contact with the thermal insulation on the cold side of the structure, it allows a rapid evacuation of excess water vapour through the under-tile ventilation, helping to improve the thermal properties of the insulating material.
On the pitched roof, the membrane offers an excellent mechanical strength performances.
CHECKED CHARACTERISTICS | NORM | UNIT OF MEASURE | VALUE |
---|---|---|---|
Mass per unit area | EN 13859-1 | g/m2 | 225±5% |
Thickness | EN 1849-2 | mm | 0,95±15% |
Tensile Strength |
EN 13859-1 |
N/5cm | MD: 380±15% CD: 355±15% |
Elongation | EN 13859-1 | % | MD: 45-65% CD: 60-80% |
Nail Tearing |
EN 13859-1 |
N | MD: 280±15% CD: 280±15% |
Resistance to water penetration | EN 13859-1 | Class W1 | |
Water impermeability | EN 20811 | m | 4 (average value) Minimum: 2 |
Artificial ageing Tensile strength after ageing Resistance to water penetration after ageing |
EN 13859-1 | N/5cm | MD: 342±15% CD: 320±15% Class W1 |
UV Resistance | Internal method | 4 months | |
Water vapour transmission property |
EN 13859-1 |
g/m² x 24h m |
WDD: 740±15% Sd= 0,03 23°C 93/50% RH |
g/m² x 24h m |
WDD: 1820±15% 38°C 93/50% RH |
||
Dimensional stability | EN 13859-1 (80°C) |
% | MD : -1<ΔL<0 CD : -0<ΔL<0,25 |
Flexibility at low temperature | EN 13859-1 | °C | -40 |
Fire reaction | EN 13859-1* *Product supported by wooden board |
E | |
Air permeability | EN 13859-2 | mᶟ/h m² | <0,3 |
For information regarding use, handling. storage and security see DOP
Product subject to CE mark according to EN 13859-1/EN 13859-2
The product complies with the requirements of ZVDH (German roofers association) Class UDB-A
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