XL Joinery Doors are solid core doors that are totally interchangeable between all joinery frames. All XL Joinery doors comply with the new building regulations, fire audit requirements and use a 25mm solid core for improved energy efficiency. This premium fire door, from the FD30 range, is an engineered, rigid core door finished in Light Grey. The FD30 Fire Door will keep you and your family safe in the event of a fire. The timber on this multi-chambered door is strengthened using LVL (Cross Laminated Timber), which improves your home’s security and makes it less vulnerable to impact damage.