Comparing T18 and T35 sheet prices per square metre of roof cover

A steel sheet has an overall width and a smaller effective covering width. Some of the material is needed for the overlap. Therefore, two prices per square metre may describe different quantities of finished roof. In a request for quotation, it is best to ask straight away for the rate per covered square metre and for the total price of all the sheets ordered.

Also check whether the stated amount includes tax. The difference between net and gross alone can change how a quote is received. When comparing, add the sheet thickness, type of coating and colour. Without this information, it is easy to compare thin material in a basic finish with another product that has different parameters and conditions of use.

An indicative example from the price list of 28 October 2026 concerns steel 0.50 mm thick with a 25 µm polyester coating. For one T18 variant the price was €8.41 net, i.e. €10.34 gross per m² of coverage. For the T35 indicated in the same price list it was €9.20 net and €11.31 gross per m² of coverage.

These amounts describe specific catalogue variants and do not constitute an offer from izoprofil.org. They should not be attributed to every sheet named T18 or T35. A different thickness, coating or order batch may change the price. The example does, however, show that the difference between profiles can only be assessed reliably with consistent units and parameters.

In the example cited, the difference is €0.97 gross per square metre of effective cover. At 100 m² of coverage ordered, this gives €97.00 difference in the sheet metal alone. However, this is not a comparison of entire roofs. If the choice of profile involves changing the supports, flashings or connection layout, the other items must be recalculated.

T35 has a higher profile, but this does not mean you can automatically save on battens. The permissible spacings depend on the specific section, thickness, steel grade and loads. Sometimes a lower profile with appropriate support will be more advantageous. In another building, a higher profile or a structural sheet selected from tables may be necessary.

The length of the sheets, a non-standard colour, the coating and the method of protection on the underside are significant. Anti-condensation fleece, if used, is a separate product feature. It does not replace thermal insulation or a ventilation design. The quote should make clear what finish of the underside is supplied and whether it corresponds to the planned application.

Transport and unloading are added to the price. With a small order, their share can be large. Long sheets require a suitable vehicle and safe handling. Also check minimum quantities and the rules for ordering additional items. Buying a few missing elements can be more expensive than an accurate measurement made before the first order.

Start with the roof layout and the number of sheets. Then count the flashings for the eaves, ridge, sides and roof penetrations. Add the fasteners and seals specified in the instructions. For a layered roof, include the substrate, ventilation and insulation. Finally, add labour and site organisation costs.

Do not apply a single percentage allowance to all roofs. A simple rectangle and a roof slope with many valleys generate different waste. The profile dimensions also affect the fit of the last sheet. The final order should result from measurement and the laying method, not just from the area given in the listing or architectural design.

Provide the location, the building’s purpose, the roof dimensions and the support spacing. Give the desired colour and the requirements for the coating. If you do not have a steel sheet selection design, state this clearly. The seller can help prepare a specification, but the load-bearing decision requires structural data. Price should not be the first and only criterion.

Ask for separate prices for the sheets, accessories, delivery and installation. Make sure the quote’s validity period is stated. The most favourable offer is the one that covers the material suitable for the building and clearly describes the scope. A difference of a few złoty per metre matters only when you are comparing genuinely equivalent solutions.