Dot Dab Plaster wall - 35mm box? Plasterer at odds with electrician

[JLeague]

As part of my spec I said that I wanted 35mm back boxes. The walls have been taken back to the brick and will be dot and dabbed with plasterboard and then skim finished.

Electrician said that he can just screw the backbox onto the wall without digging into the brick because onces its dotted and dabbed the wall will come forward 35mm and cover the box.

Plasterer is adamant that is wrong and has said that he will do dot and dab but the wall will not come out as much so the boxes will protude.

 

[Pete999]

What is your question?

 

[JLeague]

What is your question?

How do I solve the impasse? I don't know who is right or wrong.

 

[kropaske]

If the walls are dead level there will be 10-15mm adhesive behind plasterboard so won't cover the back boxes.
I always chase where the back box is going to be and fix them after plasterboard are installed, that way you can set it excacly how you want it and no complains

 

[snowhead]

If the wallboard had insulation on the back it probably would come out 35mm.

If the Electrician has assumed, without confirming the wallboard spec with anyone, that the boxes will be covered then it looks like the Electrician has got some chopping out to do, at his or her own expense.

 

[JLeague]

If the walls are dead level there will be 10-15mm adhesive behind plasterboard so won't cover the back boxes.
I always chase where the back box is going to be and fix them after plasterboard are installed, that way you can set it excacly how you want it and no complains

Thanks

So it seems plasterer was correct - 10-15mm for adhesive, 12mm plasterboard, 3mm skim so about 25-30mm.

I have just spoken to the electrician and he said he had quoted and assumed the new plasterbaord would cover 35mm - if I still want 35mm boxes then its extra or he can fit 25mm boxes which he said really is what everyone asks for.

I am on a tight schedule and for 30 sockets he is looking at 2/3 days more work - I might just have to bite the bullet and go with 25mm boxes.

 

[Pete999]

How do I solve the impasse? I don't know who is right or wrong.

Sink the boxes in to just below the depth of the muck and the plasterboard. I would go with the boarder he has to try and make the finished wall level and straight, regardless of what you say about 32mm deep boxes. you can;t just make these assumptions with out discussing the finished job with the plasterer, older walls are bound to be a bit out of wack, should have discussed beforehand imho.

 

[kropaske]

I am on a tight schedule and for 30 sockets he is looking at 2/3 days more work - I might just have to bite the bullet and go with 25mm boxes.

Bear in mind some flat plate sockets or usb once won't go in 25mm box

 

[Ian1981]

Sounds like the electrician is just being lazy and does not want to chase the boxes in and expects the plasterer to dab out to his boxes , so more work for the plasterer.

 

[SJD]

As mentioned, some sockets won't fit in 25mm boxes - typically USB ones and some flat plate ones - but standard white sockets with a raised profile generally will be OK. So it partly depends on what sockets you plan to fit how much depth you really need.

What I will say is it a lot more work later to have to remove a box, chop out the wall, and refit a box, should it be necessary. So be sure now if you must have 35mm or if 25mm will do.

And to add, if you have 35mm boxes and they protrude at all, some faceplates won't sit flush on the wall, again the flat plate types (whereas some raised profiles can stand a slight protrusion of the box).

 

[snowhead]

I'd suggest working which boxes are more likely to be needed at 35mm and just go for the essentials @ 35mm not the lot.

 

[Teddy Lop]

dotdab has never covered 35mm boxes. Wouldn't even trust 25 TBH. your sparkys first site job?

I use 35 min for everything, even when not required protects against the client changing his mind and turning up with flatplates, stops busy switches esp dimmers being such a crush etc.

pet hate - 4 gang flat dimmer on 25mm backbox with 300 cables in it - but he used 1.5mm to do a proper job right!!

 

[Pete999]

dotdab has never covered 35mm boxes. Wouldn't even trust 25 TBH. your sparkys first site job?

I use 35 min for everything, even when not required protects against the client changing his mind and turning up with flatplates, stops busy switches esp dimmers being such a crush etc.

pet hate - 4 gang flat dimmer on 25mm backbox with 300 cables in it - but he used 1.5mm to do a proper job right!!

Must be some switching arrangement withh 300 cales Mate Jodrell Bank is it? Joke I know where you are coming from

 

[davesparks]

If you specified 35mm flush mounted back boxes and they have quoted from that specification then that is what should be installed.
Anything else and it doesn't meet specification and should be corrected at their expense.

 

[UNG]

I am on a tight schedule and for 30 sockets he is looking at 2/3 days more work - I might just have to bite the bullet and go with 25mm boxes.

2/3 days to sink 30 boxes 10mm into a wall !!, how many tea breaks is he having

Quite normal now to fit 35mm boxes and have to sink them 10 - 15mm to accommodate a 25mm dot and dab spread

 

[ChrisElectrical88]

He should have sunk them. Never getting a 35mm dab unless it’s insulated board. Don’t accept 25mm back boxes. It will limit you in the future.

 

[Baddegg]

2/3 days to sink 30 boxes 10mm into a wall !!, how many tea breaks is he having

Quite normal now to fit 35mm boxes and have to sink them 10 - 15mm to accommodate a 25mm dot and dab spread

Mornings work....

 

[Leesparkykent]

Generally 25mm boxes are fine to be screwed direct to the wall if being dot and dabbed. If 35mm then they normally get chased in 10-15mm as dabbing that far out uses a lot of gear and can be a pain.

 

[UNG]

Mornings work....

Exactly, wouldn't take much more than a day if it was engineering brick

 

[ChrisElectrical88]

Mornings work....

Exactly this, the walls getting dabbed over so it doesn’t need to be an sorta of neat. SDS on hammer with the chisel bit and shave 10mm off. In red brick it’s only taking a day, absolutely tops and that’s if you have a smoke after each box!