Waterproof Test

Whether water passes through the construction we supply: the fabric itself, the seam assembly, the closure area and the openings, tested as separate questions under one method rather than merged into a single claim. Test method: to be confirmed with the laboratory before testing, and applied identically to every specimen. Conditions required for a comparison to mean anything: the fabric and membrane specification as quoted; the seam type, thread, stitch density and whether the seam is taped, sealed or left plain; the sample size and where it is taken from the garment, since a shoulder seam and a side seam are not the same problem; how the specimen perimeter is sealed so that water cannot bypass the construction being tested; the pressure the specimen is held at and how long it is held; the ambient conditions; and the number of specimens per construction. We do not publish water column or waterproof grade figures; where a buyer's tender requires one, the sequence is to agree the method first and have the result produced on the actual construction.

In a cold weather programme, water inside a garment is not an inconvenience. Water reaching insulation displaces the air that was providing warmth, adds weight, and stays there because the wearer cannot dry the garment. Almost every field report of a leaking cold weather shell traces back to a construction decision rather than to a fabric decision: an untaped shoulder seam, a front closure without a storm flap, a pocket opening without coverage, a cuff that does not seal over the glove. Each of those is a specification line with a cost attached, and each of them is invisible in a fabric datasheet. Testing constructions separately is what allows a buyer to decide where the cost actually buys protection and where it does not.