Wooden boards for internal glass panelled doors

Hi , wooden boards are not fire resistant. you will need to use a product called masterboard or superlux or similar. These are fire resistant boards and are whitish and will need painting. Horrible finish, I would get a carpenter to fit some new fire doors if I were you.

Do these doors need to be fire rated? If so you will need correctly fitted new fire rated doors, fire rated door furniture and hinges, fire rated frames with intumescent strips and potentially infill of voids in stud walls to meet regulations . If the doors don't need to be fire rated then simple ply board of the correct thickness could be used to replace the glass but again for the time and effort involved I'd recommend replacing the doors or covering the glass with a fablon type film from a DIY store. Consult your local council if you are unsure whether the doors need to be fire rated or not.