All of our doors are made using the latest engineering construction processes. All of our hardwood and oak exterior doors have an solid engineered timber core with real timber veneers and solid timber edgings. These processes mean that the majority of our doors can be given a 10 year manufacturers guarantee (see individual product descriptions as external softwood and a few others are exempt). These manufacturing techniques heavily reduce the risk of shrinkage and warping and due to this are now considered the industry standard for high quality doors. Care must be taken when trimming doors, they should not be trimmed beyond manufacturers recommendations so as to avoid exposing the inner core.