All our frame, brace and ledge style doors have a 70mm thick framework with traditional mortice and tenon joints which are glued and screwed for added strength. On hardwood doors we use a 'V' jointed board approx 150mm wide, the boards are set into the framework and are 20mm thick, again all boards are glued and screwed to the framework. On hardwood doors all screw holes are filled with hardwood pellets then sanded smooth ready for treatment. Hardwood doors are supplied untreated.
The doors can be made in Accoya as well which has many benefits compared to softwood, it has a 50 year guarantee against rotting above the ground so basically makes these gates for life, Accoya is also very stable so it lasts 3-4 times longer between treatment coats, for more beneifts on th euse of Accoya please see the attached link https://www.accoya.com/why-accoya/benefits/