Trapezoidal sheet is a roof and façade cladding material produced by roll-forming galvanised or pre-painted steel into trapezoidal profiles. The height of the profile determines the load-carrying capacity of the sheet.
It is one of the most sought-after steel cladding products in Türkiye; most factory, warehouse, barn and hangar roofs are clad with it.
Technical specifications
| Profile | TR27 / TR35 / TR40 |
|---|---|
| Thickness | 0.40 – 1.00 mm |
| Material | Galvanised or pre-painted steel |
| Type | Single skin / double skin with insulation |
| Length | Cut to the project |
| Use | Roof, façade, hangar |
Choosing the profile
The profile number shows the height of the trapezoid: TR27, TR35 and TR40 mean progressively greater height and therefore greater capacity to span.
If the purlin spacing is wide and the snow load high, a higher profile is needed. The choice follows the structural calculation for the project.
Thickness and coating
Thickness varies between 0.40 and 1.00 mm. A thinner section gives lightness and a cost advantage; a thicker one gives strength and long life.
As a surface, galvanised sheet is economical and durable; pre-painted sheet (PPGI) offers colour choice and additional corrosion protection.
Single skin and insulated types
Single-skin trapezoidal sheet serves only as cladding; it is common on warehouses, hangars and temporary structures.
In the double-skin (insulated) type, insulation material goes between two sheets; it is preferred where thermal and acoustic insulation is required.