After the boots have been worn in the outdoors a couple of times and the factory applied DWR (durable Water Repellency) is beginning to wear off apply the appropriate Nikwax waterproofing treatment to extend the life of your footwear.
Footwear is made of leather because it is comfortable, supportive, naturally water-repellent and breathable. The less water absorbed by leather, the longer it will last and the more comfortable your feet will be. Once wet, leather stretches and weakens, shrinks and becomes brittle as it dries.
Re-proof or add water repellency
This is important not just to keep your feet dry, but will keep footwear cleaner and maintain the leather's suppleness for improved durability. After cleaning footwear with water, apply the appropriate Nikwax waterproofing treatment to the entire shoe or boot, paying special attention to the stitching and around hardware (anywhere the leather has been punctured) to ensure complete protection from the elements. Reapply as necessary or after use in severe conditions. For best results let footwear dry for 24 hours before use.