An elderly relative asked me to look at the frame of their front door. It is rotting at the bottom and about 50 cm up. About 12 years ago their house had a chemical damp proof course installed and the door and frame were renewed at the same time. Now it is rotten again.
There's a line of injection points in the wall adjacent to the door. These have not been plugged, and the injection holes are left open to the elements. Is this likely to be the cause of the failure? Is it possible to restore the damp proof course by re-injecting the chemical through the same holes? What should they be plugged with?
Any advice gratefully accepted.