Impregnation Process

Raw material arrives at the plant for inspection and grading according the AREMA standards (American Railway Engineering and Maintenance – of ways – Association – The sleepers accomplishing the requested grade continue to impregnation process. The selected wood is introduced in a vacuum pressure vessel, called autoclave, at high temperature (+85°C), initially under vacuum (-68 kPa) in order to extract water, and later on under pressure (+1,400 kPa), in order to inject creosote.

Creosote is a fungicide and insecticide oil that waterproofs and immunizes the wood, protecting it against wood-eating organisms’ degradation (decay). The complete process can last from 24 to 36 hours, depending on the previous moisture content of the wood, and it shall meet the American Wood Protection Association (AWPA) Standards (

Treated wood products are inspected and tested assuring they meet the required quality. In addition, we have a permanent external third party auditing control for quality assurance certification such as Eurofins ( and SGS (