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!

 

[hasel5]

Did the spec say 35mm boxes if so stick to your guns

 

[James]

If you had more than 1 quote for the job, now might be a time to review the quotes again before work starts.
it's not a good sign when they are saying it will be extra money to do it to the specification that you originally agreed on.
you should be getting what you asked for.

 

[Mike Johnson]

1min 14seconds plus vacuum cleaning time.

View: https://youtu.be/fueNBF7s1qQ

 

[telectrix]

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!

might take me more than a day, due to old age and the fact that i'd have a smoke before, during, and after each box, with a pint of ale after every 3.
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1min 14seconds plus vacuum cleaning time.

View: https://youtu.be/fueNBF7s1qQ

fine on thermalite block....useless on hard brick.

 

[radiohead]

To the OP, ask the plasterer to generously dab all the way round each box. Often they don't...and there is insufficient board to fully support the accessory. The result is the point will never be secure and ends up being bodged in with filler when the edge of the plasterboard crumbles.

 

[HappyHippyDad]

I would have discussed this with the customer at the beginning and asked what sockets they wanted as some now do need 35mm. I did get caught out once, so that dosen't happen now. The plasterer can't be expected to bring the plasterboard out another 10mm just to please the electrician.

Of course if the electrician has specified 25mm back boxes in the quote then perhaps they are justified, but it should still have been discussed before hand.

If the plasterer puts up his boards and plasters, and then the electrician starts digging out the boxes more, the plasterer will have more (unecessary) work to do. It does seem that the electrician should just get in there and dig 35mm boxes in by 10mm (I bet he quoted to chase them all in anyway!).

 

[radiohead]

Nobody should be installing 25mm boxes anyway, it's lazy and shoddy on new work where very little extra effort is required to fit a 35mm box which will enable future changes of accessories.
So many times I've been to new builds where a new owner has proudly presented me with a load of shiny flat plate accessories to replace the cheap white originals, and you have to tell them it cant be done without replacing all the boxes. There is no excuse for it.

 

[pirate]

I would look at this another way. Why use dot and dab? It would take less time to fit proper studwork than chase out 30 backboxes, the finish would be better, and easier to obtain, the installer of the plasterboard would have an easier and quicker job, the plasterer has no extra work, and the electrician has a quicker and easier job too, with the benefit of a useable gap behind the board.

 

[telectrix]

I would look at this another way. Why use dot and dab? It would take less time to fit proper studwork than chase out 30 backboxes, the finish would be better, and easier to obtain, the installer of the plasterboard would have an easier and quicker job, the plasterer has no extra work, and the electrician has a quicker and easier job too, with the benefit of a useable gap behind the board.

and 6" lost from the width of the room (assuming 2 opposite walls are studded).

 

[pirate]

Like that would make a difference? I'm assuming we're talking about a room here, not a cupboard!

 

[Vortigern]

Slightly off topic but how do you wire the ring in this case, horizontally or vertically between sockets?

 

[JLeague]

Just an update. Even though I specced it as 35mm I have decided to go with 25mm back boxes and slim profile face plates / sockets.

I am on a schedule and I need the electrician to finish before the plasterer comes in with his team which I cannot delay as he has secured all the plaster so if I didnt start on the agreed date he would need to be paid for 2 days delay for his whole team - 3 of them.

I am not having any dimmer switches - just standard light fittings and downlights.

 

[UNG]

Like that would make a difference? I'm assuming we're talking about a room here, not a cupboard!

It could make all the difference between a kitchen optimally fitting the space or not. A 3m x 2.5m room would lose just under 0.5m² of floor area, it doesn't sound a lot but in some areas of the country that could be a very expensive 0.5m²

 

[telectrix]

Like that would make a difference? I'm assuming we're talking about a room here, not a cupboard!

no wood left for a cupboard. it's all been used for your studding, and 1 tree less to absorb C02.

 

[Mike Johnson]

Call me old fashioned, but IMO plasterboard should only be used on ceilings, dot and dab was invented to speed up construction no other reason, any muppet can do it, very little skill involved, with hard plaster, cupboards and fittings can be fitted directly to the wall no need for noggins, but it does need skill which seems to be lacking in the building trade these days.
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Like that would make a difference? I'm assuming we're talking about a room here, not a cupboard!

Kitchen units are normally a multiple of 600, 300 & 400 so any reduction of space is at a premium to get all the units in, kitchen planning needs a bit of skill.

 

[nicebutdim]

Call me old fashioned, but IMO plasterboard should only be used on ceilings, dot and dab was invented to speed up construction no other reason,

I've never seen dot and dab used and only became aware of its existence a few years back, from watching youtube videos. I don't think this technique is used in NI at all. It seems a bit mad to take a solid wall and turn it into a hollow wall.

 

[JLeague]

I've never seen dot and dab used and only became aware of its existence a few years back, from watching youtube videos. I don't think this technique is used in NI at all. It seems a bit mad to take a solid wall and turn it into a hollow wall.

I thought one benefit was having a little air gap of 10-15mm helps with insulation a bit like double glazing - but I may be totally wrong!

 

[Mike Johnson]

If I remember correctly the Gypsum White Book says sufficient dab should be put on the wall to fill the void.

 

[Ian1981]

Call me old fashioned, but IMO plasterboard should only be used on ceilings, dot and dab was invented to speed up construction no other reason, any muppet can do it, very little skill involved, with hard plaster, cupboards and fittings can be fitted directly to the wall no need for noggins, but it does need skill which seems to be lacking in the building trade these days.
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Kitchen units are normally a multiple of 600, 300 & 400 so any reduction of space is at a premium to get all the units in, kitchen planning needs a bit of skill.

I’ve never ever seen dot and dab used on ceilings as the plasterboard is fixed to the timbers by screws, dabbing it , it would simply fall down or move.

 

[Mike Johnson]

You don't dot and dap on ceilings, I thought that would be understood and did not need explaining, perhaps you are too young to remember the traditional way of constructing domestic buildings.

 

[Baddegg]

Dot and dab is a quick way to refurb old buildings whose render coat has lost adhesion...used a lot down here on old terrace buildings...never gonna be 35 mm though, cost alone would prevent it, done properly it would finish as per the original inch ish 25 mm render and plaster finish,personally I’d put 35 mm boxes in but sometimes as per the op there’s a tight window.....but don’t forget depending on age of building, you may not even get the 25 mm you need in some areas!

 

[Mike Johnson]

Dot and dab or any type of finish should not be used on top of blown render, it should all be hacked off and then you can hard plaster.

 

[Baddegg]

Dot and dab or any type of finish should not be used on top of blown render, it should all be hacked off and then you can hard plaster.

I assumed that was a given ?

 

[Ian1981]

You don't dot and dap on ceilings, I thought that would be understood and did not need explaining, perhaps you are too young to remember the traditional way of constructing domestic buildings.

Ha I miss read your post , you said plasterboard only.

 

[pirate]

If a kitchen fitter can't trim down a unit to fit the space he's not a "fitter" at all. They are adept at putting in "filler" boards to make up a gap of a few inches, and clearly prefer to do that rather than trim a larger unit to fit.

 

[Mike Johnson]

Well everyone else miss reads the post's so why not you as well, we seem to need the minutiae in all explanations or someone will come back with a question that should be a given.

 

[telectrix]

You don't dot and dap on ceilings, I thought that would be understood and did not need explaining, perhaps you are too young to remember the traditional way of constructing domestic buildings.

you mean lath and plaster with half a horse's hair in the plaster, or straw walls?

 

[Zerax]

You don't dot and dap on ceilings, I thought that would be understood and did not need explaining, perhaps you are too young to remember the traditional way of constructing domestic buildings.

I'm too young too Mike... like this you mean ?

 

[UNG]

Call me old fashioned, but IMO plasterboard should only be used on ceilings, dot and dab was invented to speed up construction no other reason, any muppet can do it, very little skill involved, with hard plaster, cupboards and fittings can be fitted directly to the wall no need for noggins, but it does need skill which seems to be lacking in the building trade these days.

Dot and dab was introduced in an attempt to increase the insulation value of walls.
For a decent plasterer dot and dab is no quicker than bond and skim

If a kitchen fitter can't trim down a unit to fit the space he's not a "fitter" at all. They are adept at putting in "filler" boards to make up a gap of a few inches, and clearly prefer to do that rather than trim a larger unit to fit.

Trimming a cupboard is the easy bit it's trimming the doors that generally causes the problems
Although I do know a couple of companies that will build kitchen cupboards and doors to customer sizes which does solve a lot of space problems

 

[nicebutdim]

Trimming a cupboard is the easy bit it's trimming the doors that generally causes the problems
Although I do know a couple of companies that will build kitchen cupboards and doors to customer sizes which does solve a lot of space problems

In most instances it would be more expensive to resize doors (if at all possible), than to dump them and fit new. Regardless, someone would have to pay for any modifcations and it would be a rather extreme solution to the problem of the spark not wanting to chase 35mm boxes.