It’s this:Could you give some specifics on the shelter? Manufacturer, dimensions> It looks like you have some type of floor.

Pressutalli PRO 6,5m × 3,4m - 580g /m² - Norfolk
Pressutalli erittäin vahvalla galvanoidulla rungolla. Huippulaadukas Norfolk -katos.
Yes, concrete slabs (40x40x5 and 30x30x5 cm) on some rock crushes and plastic.