Do I need to remove render to damp wall which I'm injecting with doc if I'm planning on lining it with a membrane? Damp can be a major issue in the home. Find answers to questions or post your own here.

[gaylemcgregor]

Hello, I have a couple of internal walls that suffer from damp at the bottom. I was planning on lining the bottom section of these walls with a membrane before dry-lining them. These particular walls have a very thick amount of sand/cement render on top and then a layer of gypsum plaster. I was planning on removing the gypsum plaster as much a possible, but to leave the sand/cement render in tact. Although I'm aware that injecting walls with dpc is not always successful / necessary I was considering doing it myself as its fairly inexpensive just in case it helps reduce the damp problem. I know that if you are planning on injecting and having a rendered surface internally you need to remove the render to a certain height and re render to stop problems with salts in the existing render damaging the new plastered surface. However, as I'm lining the wall with membrane anyway can the existing render below remain?