In Poland, the service life of trapezoidal sheet metal depends on the material, coating, environment, installation and maintenance, not on one universal number of years. T18 and T35 primarily describe the profile, not a finished durability class. It is worth checking the coating system, thickness, operating conditions, as well as the structural documentation and environmental requirements. Two sheets of the same height may have different surface protection and warranty scope. A higher trapezoidal profile alone does not protect against corrosion. When choosing, read the parameters of the specific variant, because a colour name does not describe the quality of the protection.

In Poland, the designation T18 or T35 indicates only the profile of a trapezoidal sheet, not its full specification. When buying, you should also read the core thickness, cover width, steel grade and coating, then check the intended use of the sheet and its laying orientation. The name alone does not replace a technical drawing, so it is worth comparing the product documentation and confirming whether two similarly named sheets are technically identical. A full description also makes delivery acceptance and later selection of repair material easier.

Trapezoidal sheet metal can suit a traditional house if its profile, colour and details harmonise with the building's form. This is best assessed on the whole roof slope, not on a small sample. The classical character comes from the proportions of the volume, the roof pitch, the eaves and the façade divisions. Check whether the regular rhythm of the trapezoid will emphasise a calm form or compete with dormers and decorations. View a sample and a photo of a larger roof slope, and leave the profile choice to the designer, who will verify the support, sheet thickness and loads.