filling up a cut out

[dotto]

Hi guys i have to fill up a 40mm channel which i made to run cold feed pipe to shower. Can i use cement based powder tile adhesive or is that not meant for such a depth? I want it to dry rather quickly and i have read on this forum to avoid plaster due to long dry out time. Thank you

 

[Richard C]

Don’t encase service pipes in addy/cement/plaster as thermal expansion will cause cracks. Cover the pipes with felt if you can & an appropriate width electrical cable cap; I use steel but plastic will do. Flatten/bend any which way to suit/fit & fix in place; fill out flush with addy but no more than around 12mm deep in one hit. TBH, narrow chases can be filled with Bonding plaster; it’s not a suitable tile base but a 40mm wide chase will make little difference to overall tile bond strength, even in a wet area.

 

[dotto]

Thanks for your answer Richard.....btw do i have to seal the cut out with pva before i fill the channel in with cement addy or bonding plaster? Ta.

 

[Richard C]

You need to kill the suction or the Bonding in particular will craze & crack, damp it down well with a water spray.