How to Execute an Extended Column Test: While the compression test looks at fracture initiation (is it going to crack?) the extended column test looks propagation propensity (is the fracture going to propagate across the slope). Like the compression test, this test is valid for four-finger or harder (so 4F, 1F, P, K, I) snow up to 100 cm deep. If there is a layer in question that is 100 cm deep, you can isolate the column up to 120 cm in order to test the layer at 100.