Damp Proofing

Is this chimney salts or rising damp what is the best course of action

Anonymous user 15/03/2024 - 2.41 PM

Hello, I have a chimney breast that has been bricked up for over 20 years, I recently moved into the property a few months ago and noticed either side of the original fireplace opening is a bit damp. first i thought I needed to improve ventilation of the chimney as its capped at the top and a brick has been removed in the attic space. to increase ventilation i made a hole in the original fireplace opening when i did so i found the old fireplace was filled with coal dust and rubble which i've now removed and can see the original slate damp course. over the dry spell the wet patches seemed to dry out. however once we started steaming to remove the wallpaper they have come back. however if you scrape the top layer of plaster off it seems the normal light pink colour and dry but over time goes back to the darker brown colour and slightly damp. what is the best course of action? should i chisel off all the damp plaster and treat the bricks with a salt neutraliser or do i need to inject a DPC? I do have paper work from around 1994 of DPC injection into that wall.