View the thread, titled "Electricians Tips from a professional electrician" which is posted in UK Electrical Forum on Electricians Forums.

Exactly this. The plaster to the sides of the cut out is not supported, so very weak. It can be reinforced though, using timber battens, without too much trouble:

  • Cut the hole out of the lath and plaster for the backbox with multitool (we're gonna use a steel BB).
  • Cut a couple of timber battens, something about 2" X 1" should do. They're going to go inside the wall, vertically, to either side of the hole, and need to be long enough to extend beyond a couple of un-cut laths, both top and bottom. About 150 - 200mm long is about right.
  • Reach inside the hole, and carefully pull away the plaster 'keys' from either side of the hole where the battens are to go. We want the battens to press right up against the back of the laths without being fouled by any bits of plaster.
  • Now the fiddly bit.
  • Liberally coat the face of one batten with PVA, water based gripfill, or similar. Maneuver the batten through the hole and into position vertically to the side of the hole, glue side pressed up against the back of the laths. Hold in place, and drive a screw through the plaster, through an un-cut lath, and into the top of the batten. Repeat for the bottom of the batten. You can put screws through the cut laths into the batten too if you like.
  • That side is now reinforced, and will be about as strong as you can hope for in a lath and plaster wall. Do the same for the other side of the hole with the other batten. You can now fix the backbox in place by screwing through the sides into the battens.
  • Filler over the screw holes and you're done.
I find this the best method also. ^^^^^^^
If possible though I build a "saddle" out of ply wood that you can fit through the cut out and twist into position.
The saddle is made of 2 stirps of ply as the vertical battens then one strip screwed to the back as the horizontal batten. I pre drill the fixing holes so not to split the lath's and then pull the saddle tight up against the inner wall whilst inserting the fixing screws. The back box can then be fixed in place, packed out if required to the depth needed. This method works best on double socket outlets as the saddle slides through the wider gap then twisted into position.
 
Even easier is to back the cut ends of the laths with a dob of plaster, if needed a piece of plasterboard as well.
 
I do like to surprise my customers sometimes... start clearing the jobsite, putting tools back in the van... and turn up at the door with a brush and pan.

9/10 times i get " don't worry about that... we'll get it"
 
I have a Karcher vac that has a power take off when you switch on the multi tool the Karcher starts up, when you switch off the tool the vac keep running for about 6 - 10 seconds to clear the hose, the Fein multi tool I have has a purpose made vac port that fits around the head of the tool and collects practically all the debris.
 

Reply to the thread, titled "Electricians Tips from a professional electrician" which is posted in UK Electrical Forum on Electricians Forums.

Best EV Chargers by Electrical2Go! The official electric vehicle charger supplier.

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Daily, weekly or monthly email

Back
Top