How do I fill this gap?

[jimmyn197]

I have a gap in my party wall after a fuse spur was installed I was planning on filling it with expanding foam but I'm worried about it getting into the backbox next to the plug socket.

Does anyone have any suggestions?

 

[23vc]

Foam won’t go much into the back box. [Isolate the supply and] tape the grommet hole?

Although that looks better suited to a bit of plaster than trying to get it decent with foam

 

[jimmyn197]

Foam won’t go much into the back box. [Isolate the supply and] tape the grommet hole?

Although that looks better suited to a bit of plaster than trying to get it decent with foam

I'm planning on filling it, just the holes get into the cavity of the party wall so just assumed I should fill it with foam and then plaster on that.

 

[Harry Bloomfield]

Does anyone have any suggestions?

I would fill it with sand, cement, and maybe a half brick or whatever masonry would fit. If you were ever to drill that wall, in the hope of fixing something, had you filled it with foam - you would be out of luck.

 

[SFK]

Bostik General Purpose Mortar Grey 5kg - Screwfix

 

[Notch7]

I would fill it with sand, cement, and maybe a half brick or whatever masonry would fit. If you were ever to drill that wall, in the hope of fixing something, had you filled it with foam - you would be out of luck.

I used sand and cement to fill a biggish hole after taking out a shower buried in wall - worked very well considering the deepest bit was around 80mm

 

[jimmyn197]

I used sand and cement to fill a biggish hole after taking out a shower buried in wall - worked very well considering the deepest bit was around 80mm

it’s a cavity wall though so it’s hollow on the inside. Do I just build out the hole around the edge until it’s sealed up?

 

[Harry Bloomfield]

it’s a cavity wall though so it’s hollow on the inside. Do I just build out the hole around the edge until it’s sealed up?

Yes, but it might help to pack something into the cavity first, such as insulation, to prevent the mortar dropping out behind.

 

[jimmyn197]

Yes, but it might help to pack something into the cavity first, such as insulation, to prevent the mortar dropping out behind.

Perfect, makes sense. Thanks for the help!

 

[Ivor Windybottom]

Hoover the muck out first, nothing sticks to dust.

Then daub some PVA or SBR on before gobbing in the mortar, so it actually sticks.