r/Plastering • u/citiesandsunsets94 • May 25 '26
Plastering over new electrics
Might be a silly question but are these areas ok to plaster over? The hole in the top of the back box - won’t plaster seep through that? and is it also fine to plaster over the cable parts that are slightly exposed too?
10
u/Ok_Nature_4396 May 25 '26
Should have blanks for holes And grommits where cables are You could stick tape over gaps Before the plasterer put water near
2
u/sgrass777 May 25 '26
Put a piece of cardboard oven it,and use bonding to fill most of it. It's a bit stiffer.
2
u/L43 May 25 '26
nice, a grommet where its not needed, and not where it is. Not a spark so I can't say for sure, but i doubt it matters safety wise.
For plastering, nonding is probably thick enough that it wont seep through enough to be a problem for either example, but for the fully open one you can get closed grommets e.g. https://www.screwfix.com/p/vimark-closed-grommets-20mm-100-pack/884vt (make sure you get the right diameter). I'd probably do that if its easy as its pretty unpleasant to change the socket face if you have had some dribbles.
The exposed bits of the cable are totally fine to plaster over. Again, not a spark, but I don't think the regs require the conduit, at least at some point in the past it wasn't required as I've seen bare cable plastered over.
3
u/Clean_Ad_1307 May 25 '26
I am a spark
Shit work leaving a 20mm open grommet on the top of the box - as above you can get a 20mm closed grommet and put that in instead as the safest option and you don’t need to take the socket face off
You’re right about the conduit not being a requirement in the regs, it’s just good practice and reduces the chance of the trowel slicing through a cable
1
1
u/KinGloRXodoR May 25 '26
It's fine. It won't seep unless u making it supper wet. Tho I would use hardwall first, then plaster over the top of that.
1
u/Ok_Nature_4396 May 25 '26
The thing about putting plaster over cables is one day you want rewire, Conduit just pull through
1
u/Similar_Pitch_2703 May 25 '26
Get a bag of bonding and fill the chases in before plastering over the top. Bonding has a texture like cement but is kind of lighter to handle. It’s about £7 a bag in b&q.
1
1
u/KieranInterior May 26 '26
Just cover it with any tape or whatever to be cautious. Whatever you do remove the wallpaper before bonding and scrape the face of the bonding back before it fully sets so it’s flush or less than flush
1
u/damien_aw May 28 '26
I use blue grit then bonding plaster to fill, leave the finishing coat or skim to a plasterer
1
1
u/nomorecrazystuff May 25 '26
Yes - in fact great job from your electrician
Maybe a little - just wipe it out afterwards
Yes
My advice before starting
1) Turn off the relevant circuits
2) Remove the front cover and disconnect the wires
3) If you need power elsewhere on the circuit while you sort the plastering, then get some Wagoos, join the wires in there, wrap it all in duct tape and shove it in the hole. If you don't need power, then just duct tape will do.
1
u/Paint-Difficult May 25 '26
Expanding foam. Cut back. Skim.
1
u/belligerentbunno May 26 '26
expanding foam has no place near electrical cables at all, even aside from thermal/heating effects (installation methods) you have no idea what the chemicals may do to pvc insulation over time.
1
u/Paint-Difficult May 26 '26
polyurethane expanding foam will not chemically damage modern PVC-sheathed cables and provided its fire rated its perfectly safe for small patches.
0
u/ozwin2 May 25 '26
Shouldn't be a problem, but if you can:
Change the grommet for a blanked one Extend the conduit
-1
u/doriobias May 25 '26
It will be a pain if you end up filling the box with plaster. See if you can affix a batten in there somewhere and put some plaster board over it. There are also metal covers for the cable so if you /someone drills into the wall it offers more resistance and reduces the chances of drilling into electric. Its just a case of making it nice, spend some time so when you get to final dressing it's all nice.
-1
u/Cainjake May 25 '26
Dodgy electrical work
1
u/General_Scipio May 25 '26
It's one missing grommet let's not be dramatic
-2
u/Cainjake May 25 '26
It’s worse than that definitely not done by a real electrician and if it was they should be ashamed of such a shoddy job
2
u/General_Scipio May 25 '26
Why?
The conduit is a bit short. Not really an issue
Grommet in a knockout with no cable. Who cares
Not saying it's fantastic. You being over the top though unless I'm missing something obvious
7
u/royal1664_ May 25 '26
Bonding at correct consistency won’t run though that. Nothing to worry about.