Making Good Wall After Pipe Insulation

[mache]

Hi Guys, Just wondering how you would make good a wall after insulating pipes that go through. My boiler is located in small utility room on the back of the house and the pipes feed through a cavity wall. I have just put new climaflex insulation on the pipe runs as the old stuff was in a pretty poor condition. The pipe justrun though big hole that had been previuosly knock through the cavity wall blocks. I was thinking of now filling the remaining hole space now with a standard expanding foam to seal against drafts entering the main building. Does anyone know if the expanding foam is OK with climaflex, or would it degrade it. Previously it had been just rendered in with mortar but I thinkthe right amount of expanding foam would be better.
Thanks
Martin.

 

[AWheating]

cover the lagging with insulation tape/duct tape if your worried about the expanding foam reacting with the lagging while its wet/setting.