Back boxes 5mm sunken into plasterboard walls

[RachelG]

Hi all,

I'm renovating my first place and have basically gutted it. My electrician fitted 35mm deep back boxes onto the breeze block walls when he did first fix. I've decided to batten the walls out with 25mm battens/PIR insulation and then fit plasterboard over, ideally 15mm acoustic plasterboard for better soundproofing. That would mean the back boxes would be 5mm deep into the walls, is that a safety hazard?

Thanks
Rachel

 

[roys]

I certainly would not be worrying about that, you might need to buy a packet of slightly longer screws, but they are as cheap as chips.

 

[Sharpend]

Concur with Roys

 

[ProDave]

Just make sure the hole in the plasterboard is cut neatly and not over size.

 

[drooper]

Just make sure the hole in the plasterboard is cut neatly and not over size.

Absolutely crucial, unless you want to be trying to fill and fill and fill,
We cut the heads of 50mm 3.5 screws and wind them inro the lugs of the backboxes, they will pierce thru plasterboard when fixed to give you a guide where to cut out , but cut really carefully as prodave said

 

[roys]

Watch your back with 15mm acoustic plasterboard it is as heavy as a big bag of heavy things.

 

[Mike.J]

The acoustics will transfer through the back box into the room, it has formed a bridge, I have not done this in the UK but in France they sell special back box's that are like a plasterboard box that is acoustically sealed (airtight) and does not penetrate the sub structure, I would suggest removing the 35mm back box in the breeze block and replace them with an acoustically sealed version into the plasterboard thereby separating the zones on either side of the wall, even clips fixing the cable to the wall can transfer sound.

https://www.leroymerlin.fr/produits...r-multicloison-1-poste-s-lexman-72049005.html

 

[RachelG]

Thanks all!