Dot and Dab Thickness

[Steveb21]

Socket boxes are 25 mm deep, and the conduit entering them is 20 mm diameter.

The wiring has been run continuously in conduit through the floor (which has now been poured with liquid screed) and then up the walls.

The original finished wall build-up was planned as:
25 mm socket box fixed directly to the wall
10 mm dot-and-dab adhesive
12.5 mm plasterboard
3 mm skim coat

Total build up 25.5mm

I’ve now realised this won’t work, as the conduit will clash with the wall build-up.

What are my options at this stage?

Cut the conduit off at screed level and chase the wall so the socket boxes and conduit can be recessed further back?

Or

Increase the dot and dab depth to around 20 mm, followed by:

12.5 mm plasterboard
3 mm skim
Total wall build up would then be approximately 35.5 mm.

 

[Steveb21]

.

 

[noseall]

Socket boxes are 25 mm deep, and the conduit entering them is 20 mm diameter.

The wiring has been run continuously in conduit through the floor (which has now been poured with liquid screed) and then up the walls.

The original finished wall build-up was planned as:
25 mm socket box fixed directly to the wall
10 mm dot-and-dab adhesive
12.5 mm plasterboard
3 mm skim coat

Total build up 25.5mm

I’ve now realised this won’t work, as the conduit will clash with the wall build-up.

What are my options at this stage?

Cut the conduit off at screed level and chase the wall so the socket boxes and conduit can be recessed further back?

Or

Increase the dot and dab depth to around 20 mm, followed by:

12.5 mm plasterboard
3 mm skim
Total wall build up would then be approximately 35.5 mm.

The conduit up the wall is pintless and potentially costly. Cap it with standard capping. It might be tricky to cut though? I would base your thickness measurements on a minimum of 25mm and work upwards, depending on the trueness of the wall.

 

[Steveb21]

Something like this:

TTE Galvanised Steel Channelling - 12 x 2000mm | Wickes.co.uk

TTE Galvanised Steel Channelling - 12 x 2000mm

www.wickes.co.uk

A bit of a pain, but I guess it’s still a manageable situation to resolve.
I’ll need to be careful when cutting the conduit flush with the screed as I don’t want to risk damaging the wires!

Would it be worth recessing the conduit and maybe the 25 mm box into the wall at the same time?

 

[danfre]

Use a metal extension box onto the front of the existing back box

 

[noseall]

Something like this:

TTE Galvanised Steel Channelling - 12 x 2000mm | Wickes.co.uk

TTE Galvanised Steel Channelling - 12 x 2000mm

www.wickes.co.uk

A bit of a pain, but I guess it’s still a manageable situation to resolve.
I’ll need to be careful when cutting the conduit flush with the screed as I don’t want to risk damaging the wires!

Would it be worth recessing the conduit and maybe the 25 mm box into the wall at the same time?

The conduit can be channelled in yes. Recess the back box - why? I'm guessing because you have secured the conduit to the back box ?

 

[Steveb21]

The conduit currently connects to the holes in the metal back box via female conduit adaptors, which can be removed.

So I believe there are two options

1. Use thicker dabs to accommodate existing setup

2. Remove conduit that runs up the wall into the metal box and replace it with metal channelling. This will allow for reduced dab build up.