What is hydrolysis? (Boot sole separation)

Sole Units will degrade when your footwear is used only occasionally and is stored for long periods of time. Sole units degrade faster than if the footwear is worn regularly. Hydrolysis is a normal material aging process that occurs in all footwear with a cushioned PU midsole independent of the manufacturer. The process also occurs in automobile, tires, ski boots or helmets and does not represent lower quality or even a quality issue in materials or workmanship.

There are two types of sole injection technology popular with outdoor boots: EVA and PU. LOWA uses PU Injected Technology, to extend the life of their boots.

PU vs. EVA
  1. We use PU on our midsoles. It's a terrific shock absorber, rebounds well, will last longer on the trail and offers better comfort. You will get two to five times the performance life compared to molded EVA midsoles.
  2. When a PU midsole begins to deteriorate, you'll see small cracks along the injection area, above the sole unit. This is an indication that your boots are wearing out.

* If you are experiencing sole unit separation, or degradation, please send us an email. Our customer service team will contact you regarding the age of the boots and what steps can be taken regarding the sole separation.