My house had a chemical DPC 25 years ago. It has solid walls and built 200yrs ago. On some sections of the interior walls a damp meter reading shows red at skirting level and up to 1ft in some places and 1 metre in others. About 6 months ago we dug out the soil to about 6inches below DPC holes as this was bridged and also a few small areas below skirting were bridged so we hacked this plaster off. The walls are still reading red and I wondered how long the walls take to dry out and read green? or do they never dry out and read green unless I re do the plaster as you have said in other replies with the salt retardent/sand and cement mix? Also the fact it was bridged, has this broken down the chemical DPC? or will it start working again now that I have un bridged these areas,or will it need injected again? Note the rest of the room is still working and showing green on meter reading.
Red damp reading in old house
