i have a problem with damp in my internal hall wall.
it has had a damp course put in over 14 years ago ( injection ).
it was injected one brick above the floorboards.
i have taken the old plaster of up to about one meter high.
i intend to inject using dryzone, i would like to know if i should inject above or below the exsiting damp course?
when i took of the old plaster i found that the wall has been painted black ( i assume to be some sort of sealant ), it also has pathes of salts.
can i still put a neutraliser on the wall ( even with this black stuff on it )?
when i took of the old plaster i noticed the plaster was browning and not the render type of plaster, would this have affected the performance of the orginal damp course?
any help appreciated.