Water Column Test - TenCate Outdoor Fabrics

The water column test is a way to determine how many inches of water can stand on the fabric before droplets pass through the fabric. For example, a water column of 600 mm means that there can be as much as 60(!) cm of water on the canvas before it starts to drip through the canvas. Although this will not occur in practice. After all, that's already more than there is normally in a bathtub, and probably the structure wouldn't be able to withstand that. A water column of 60 centimeters is therefore more than is needed in practice.

The water column test
With the water column test, we determine how many inches of water can stand on your tent or awning fabric until a drop of water passes through.
First, we allow the test surface to be full of water. Then we check whether the gauge is at zero. Then the test can start. We are constantly watching for water droplets to pass through. When 3 drops have formed in different places in the fabric, the test is finished. We then look how high the water is. For example, this can be 60 cm. This means that the water column of this fabric is 60 cm. So, there can be 60 cm of water on the fabric before any drops pass through.
This test complies with the following ISO standards:
ISO 811: Hydrostatic pressure test
ISO 139: Textiles – Standard atmospheres for conditioning and testing