Browse Forums Renovation + Home Improvement 1 Nov 16, 2021 1:10 pm Hello everyone. This is my first post and the reason for signing up. I'm looking to fill the gap between a brick fireplace and a plasterboard wall before adding trim. Ideally to add a bit of strength and weatherproofing. It's not an ideal thing to have to do but it's a problem we've inherited from the previous owner. I've provided photos. To explain. In our house - there once was a fireplace. At some point in the last 10 years, someone built a small brick wall in front of the old fireplace to house a gas heater, sheeted over the brick and added trim to seal it all up and transition from the new brick to the then lath & plaster walls. See original pic. We've gutted the room, removing the lath & plaster which revealed the gap behind the trim on either side of the gas heater brick wall. I've repointed the fireplace, insulated, rewired and had the room re-sheeted and now plan to put it all back together which means adding trim where the plasterboard meets brick. I'm looking for advice on what to use to fill the large gap (larger now due to the thickness of lath&plaster) behind the trim. I removed an amount of what looked like plaster of pairs from behind the trim in the initial demo. Should I just reverse the process, or is there another method you would recommend? Would expanding foam do the trick? The new wall is not particularly stable so I'm hoping that the filler, trim and mantle will make a robust structure. Many thanks for the help if you can offer it. Original with trim on either side. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Exposed brick without trim (Original Mantle pictured, is now to small due the original thickness of lath & plaster). Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Gap on left-hand side Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Gap on right-hand side. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ 2 7544 Thank you alexp79 and gommeqld for your advice, that's very helpful, thanks 3 7945 What we have done in a few theatres ( including my own) is run 2 layers of 13mm gyprock, but sounds insulation especially for the bass is really tricky as a lot of that… 4 2577 |