I have seen an exterior back door in wickes that fits the opening to my door. It is an aluminium door that says it needs fitting into a timber frame (although it is already in an aluminium frame). I am having trouble working out exactly what this means.
Do I have to buy a timber frame then install this and screw the new door and frame in to this? If so, couldn't I just put any old wood (not a purpose built timber frame) up around the door opening and screw the aluminium frame and door into this?