Screwing into previous damp walls

Hi.

I am about to undertake a shower installation, and in doing so need to erect some studding to hide pipework etc. I was going to do this by screwing/plugging battons onto the walls against which the shower will be positioned.

My concern is that these walls were recently re-plastered - with sand/cement/waterprooofer mix - due to hygroscopic salts causing damp in the plaster. Would drilling and plugging into these walls cause problems and reduce the damp protection offered by the re-plastering?

If so, is there anyway of screwing into these walls without causing a problem? I was considering injecting a waterproof mastic into the holes before and after the plug is inserted. I feel this method may not work however due to the mechanics of the masonary plug disrupting the mastic.

There would be no problem in drilling/fixing into this wall.

But even so, I can't see your concerns if you are erecting a stud frame to hide the wall in any case

i sort of have the same situation when i tank a walk. it effectively becomes a membrane and any drill holes puncture it.

to counter any potential for damp to escape i put clear silicon sealant into the drill hole before pushing in the fixing.

so would say the water proof mastic would be just as good. i would probably put dpc between the studwork and the wall just as a precaution.