How To Fill Gaps Between Brickwork In Internal Cavity Wall

[MrMiller]

Hi Folks

I'm redoing our bathroom and got some lime mortar mix in order to fill some gaps between the bricks before attaching backer boards / plasterboard:-

Thing is, now I've got it (!), I'm thinking how do I do this - just push it in and hope for the best / not worry about it?

I'm thinking this is a cavity wall, so will I not just land up with bits falling off the back and down into the void? Would this be a big deal or nothing to worry about?

 

[blup]

Many wouldn’t bother as you have the cavity and the dot and dab for insulation. But with a thin trowel and plenty of time you can do it without dropping too much in the cavity by packing out the front only. If you have to go deeper, pack out and let the first part dry before finishing.