Hi
I am restoring an appartment. The whole plumbing and heating system is being replaced. The plumbers have done their first fit in the bathrooms - dug channels for pipes etc and installed hidden cistern. Only thing is that the wall between the bathroom and the next room was pretty thin. In making their channels they have gone right through to the other side. Some of the holes are pretty large - a foot square maybe. I need to fill these holes. All the advice I can find online relates to filling a hole where it doesn't go right through to the other side - more indentations than real holes. The wall is made of a sort of hollow brick with render then plaster on top. It is obviously not a supporting wall.
Basically how do I best fill these holes ? Can I just fill them with some kind of cement product or do I need to reinforce it with some kind of steel mesh? Will the "cement" be secure enough just "pushed" into the hole and then covered with plaster. I am saying "cement" but obviously need to do some research on the best product. The appartment is in Italy and so I need to see what products are on the market here.
Thanks for any help.
Mike