A square metre of panel is a convenient unit for comparison, provided you know how it has been calculated. In practice, you buy specific pieces, lengths and configurations, and some material may be left over after cutting. It is therefore worth converting the price per m² to the whole order and to the area that will actually end up on the wall or roof. Ask whether the unit refers to the cover width, the overall width or the commercial rules stated in the quote. Part of the cladding that forms the joint may not increase the finished wall area. It is therefore not worth calculating the purchase yourself from a random measurement of the full sheet width. The modular value of the specific product is needed.

A wall sandwich panel is suitable where a hall, warehouse or workshop needs to be enclosed quickly, but its usefulness depends on the conditions on both sides of the wall. Before choosing, establish whether the interior requires a specific coating, chemical resistance or hygienic solutions, and compare the declared insulation and reaction-to-fire class of the particular product. Also check whether the system includes suitable joints and accessories for corners, openings and the roof connection, since these details often determine the airtightness and durability of the enclosure.

A single building may contain a warm workshop, a cool warehouse and a room with a lot of moisture side by side. They do not need identical panels, but their joints must form a coherent system. Thickness is selected after checking thermal insulation, load-bearing capacity and fire requirements. None of these conditions should be assessed solely on the basis of the others. Record the planned temperature in each zone and the heating period. It matters whether the door opens all day or only a few times a week. A product packing room may need different conditions from a warehouse for empty boxes, even with the same floor area.