Selecting roof panel lengths from the stock actually available

Also check the core type, thickness, colour and coating parameters. Two similar panels do not necessarily have compatible interlocking profiles. If a few pieces are missing, adding elements from another product family may require a separate joint. Do not plan the entire roof slope based only on a photo of a stack of panels in an advertisement.

Measure the section along the actual roof slope. The horizontal projection is shorter than the inclined surface. Take into account the eaves, ridge or wall termination detail. The order length should result from the adopted details, not from an arbitrary allowance added to the building dimension.

For modernisation, check dimensions in several places. Old walls and supports may not form a perfect rectangle. Also record the position of the purlins. The required panel length and the permissible distance between supports are two different issues. Even a very long available element may require several intermediate supports.

If you need elements 5.20 m long, a 6.00 m batch may allow them to be made without longitudinal joints. However, the cutting and edge finishing conditions must be checked. With ten strips with a cover width of 1.00 m, you buy 60 m², although in a simple model you will use 52 m².

The remaining 8 m² does not automatically become a fully usable reserve for the roof. Short sections must have an appropriate use and their edges must be preserved. In the calculation, check whether the lower warehouse price compensates for the waste and the work involved in cutting. Compare the total with an offer for elements prepared to the correct length.

Before cutting, write down the sequence of elements. This makes it possible to see whether a shorter piece can serve another part of the roof slope without an additional, unforeseen joint.

Transverse joining is only possible in a system that provides for it. It requires suitable support, overlap geometry and seals. It often also affects the required pitch. Two short panels laid one after the other do not make a watertight roof without detailing this junction.

For stock material, check whether the ends are prepared for such a joint. The direction of the cut-back and of the panel laying may be important. Do not accidentally turn an element round just to make the length fit. If the solution requires a large number of additional details, a quick purchase may not mean quick completion of the work.

A long panel needs a suitable vehicle, a method of lifting and space to manoeuvre. Check the access route and the area where equipment can be set out. In the model renovation in Łęczna, a narrow entrance may rule out convenient unloading of the whole pack at the building. It is worth identifying such an obstacle before purchase.

Determine the number of supports and how the material is secured during handling. Do not select grips based on weight alone. The length and the susceptibility of the element to deformation also matter. If the material is to wait for installation, prepare a storage area in accordance with the requirements for the given panel.

Compare the markings and dimensions with the reservation. Inspect the ends, locks and sheet surfaces. Determine whether the batch has defects described as second grade. Information about thickness and colour does not replace a description of the material’s condition. A damaged joint may limit the usefulness of the panel more than a scratch in the middle of the cladding.

• Count the elements by length.
• Check that the family and coverage width match.
• Confirm the condition of the edges and the coating.
• Record the unloading rules and responsibility for damage.

Finally, agree the installation date. Material available the same day will not speed up the works if the structure, flashings or equipment are still not ready.