Hi guys!

This is, what I am looking for:

“Tent fabric ratings - Most tents are made using polyester fabric which is not waterproof. So a PU (Polyurethane) coating(s) is applied to provide ‘waterproofness’. The hydrostatic head is a measurement of how waterproof the fabric is, and is measured in mm, usually ranging from 800mm up to 10,000mm. There’s no internationally recognised standard of what specific rating ‘waterproof’ is, but 1500mm is widely accepted as being the minimum to be deemed waterproof and able to handle most rain conditions. A tent with a 1500mm rated fly means a 1500mm high column of water can be held up against the fabric for one minute before a drop of water seeps through.”