the classic industrial roofing solution

With millions of square metres installed worldwide, Onda 177® sheeting in polimglass® material has become the de facto reference standard in lightweight industrial roofing.

Onda177 is a corrugated sheet with a pitch of 177 mm, it may be ordered in the extremely attractive Tecno Imac glossy finishes. A range of accessories and specific fittings completes this product line, the ideal solution for roofing agricultural and industrial buildings requiring proven resistance against chemical agents as well as an attractive aesthetic effect. Onda 177 is manufactured in Italy in polimglass®, a material capable of assuring a roofing solution with high durability, elasticity, lightness and colourfastness.

Technical specifications

Standard length mm fino a 13.500
width mm 1.110
useful width mm 1.060
average thickness* mm 2,90
weight* kg/m2 6,10
thermal expansion coefficient °C-1 3,99×10-5
unitary thermal transmittance W/m2k 4,68
breakage load kg/m2 701

anticato colour


terracotta colour

The material

Onda 177 is a Polimglass® roofing sheet (learn more about it), a material made and patented by Tecno Imac obtained by the convergence of three different individually extruded thermoplastic layers at a terminal extrusion head. The result is a single sheet that is stratified in three different layers, each of which is optimised to perform certain functions:

1-top layer: solid-coloured in PMMA (Metacrilato) for colours and finishes that are perfect and highly resistant to UV, weather and environmental exposure to chemicals of any kind.


2-middle layer: a mixture of different polymers loaded with micronized inert material, for a low thermal expansion, good acoustic behaviour and resistance to bending.


3-bottom layer: thermoplastic compounds for maximum resistance to impact and chemical aggression from underneath.The result of this particular combination of thermoplastic materials is a stable and resistant synthetic product, applicable to any environmental situation, without fear of attacks of acid vapours of any kind, whether industrial or agricultural, or the most aggressive saline environments.

Assembly tips

Roof sheeting must be laid on a framework of purlins whose span interval is proportional to the prevailing loads and the inclination.
Position the first sheet with the stamped-marking side facing towards the outside of the roof.

Warning: allow for normal thermal expansion by drilling the sheet fixing holes a bit wider than the fastening screw shank diameter, typically a 10 mm hole diameter for 6.5 mm screws.

Then the second line of fastenings should be fixed to the next higher purlin.
Establish an overlap between the second and first rows and fix the line of screws through the overlap.
To maintain alignment, we recommend using a reference lanyard anchored to the ends of the purlin. Proceed in a similar manner with the subsequent sheets, up to the last.

If necessary, the width of the last sheet can be adjusted by trimming it with an angle grinder.
The lowermost sheets must be secured along the eaves gutter purlin with a screw-down fastening on every crest. On intermediate purlins in areas subject to normal wind conditions, the sheets may be secured with fastenings on alternate crests, taking care to fully fasten the sheets with lateral overlaps.
The drawing illustrates the example of an insulated and micro-ventilated roof built with Onda 177 sheeting anchored to omega section profiles, interposed with a breathable sheath as an anti-condensation measure. The fins of the omega profile are used to anchor a rigid panel of self-supporting insulating material. The roof ridge is covered with multi-purpose ridge cap pieces which assure optimal ventilation. ProAir ventilation elements are installed both at the eaves fascia board and under the multi-purpose ridge cap. Eolo 3 ventilated sealing elements are installed under the ridge cap when the inclination is less than or equal to 21% (12 °).


ico_download_pdfscheda tecnica
lastra 30Coppi Italiano

ico_download_pdfManuale di montaggio*
lastre leggere Italiano

ico_download_pdfvoce di capitolato*
lastre leggere Italiano