Cuprinol ultimate garden wood preserver has a superior water based formulation that works in 3 ways its uv filters give long lasting colour for up to 5 years added waxes and resins provide advanced weather protection and active ingredients penetrate deep into the wood to protect against rot decay and blue stain ultimate garden wood preserver can be used on all types of rough or planed wood such as sheds fences summer houses gates and arbours drying time 2 6 hours