Title: +038=627.001-##001T_03-Fasadevasksystem NorAcon - International Code of Practice (ICOP).pdf
O.3.6.1.4.3 The waterproofness and level of breathability of outer garments vary and are rated in accordance with standard tests. Manufacturers typically describe the waterproofness and breathability of fabrics using two numbers. The first number is in millimetres (mm) and is a measure of how waterproof a fabric is. Put simply, the test uses a vertical tube, to the bottom end of which is fixed a piece of the fabric to be tested. Water is poured into the tube until it reaches a height (actually, a pressure) at which the water begins to seep through the fabric, e.g. 10,000 mm. The bigger the number, the more waterproof the fabric is.O.3.6.1.4.4 The second number is a measure of how breathable the fabric is, and is normally expressed in terms of how many grammes (g) of water vapour can pass through a square metre (m2) of the fabric from the inside to the outside in a 24 hour period, e.g. 10,000. The bigger the number, the more breathable the fabric is.