Hi Apologies if this is a stupid question, I'm not a tradesman.... I need to fill in gaps underneath a fitted corner bath due to cluster flies gaining access through the cavity wall. I've looked underneath the bath and can see quite large gaps in the plaster behind the copper hot and cold water pipes, along with some gaps where the floor meets the wall. The only solution I can see to this is to use expanding foam with an applicator gun to fill in these gaps. I have spoken to the plumber who fitted the bathroom and he has suggested that to remove the bath may cause damage as he has fitted it securely with silicone etc and would be reluctant to try and remove it in case of damage to the edge of the bath and the tiles. It's an hydrotherapy bath so not cheap to replace should it get damaged and this also means there is lots of extra 'stuff' going on in the space underneath the bath. I have looked online and keep seeing things saying that expanding foam shouldn't be used near copper pipes, however the articles/threads are years old so I was wondering if things have progressed in that time and if expanding foam and copper pipes have made kissed and made up or if I need a plan B?