Boxes into lath and plaster

[Jon Bridges]

Interested to know if anyone has any special techniques for putting back boxes into lath and plaster. Cutting the lath's can be tricky, but also how to attach the box. I generally use a plasterboard box, but if the plaster is thick you cant get the clips behind the lath's, and if they are only supported by the plaster the box will soon fall out, as I found out the other day.

 

[robd]

I normally say no you can't have a socket/switch on that wall! How about that wall over there?

 

[telectrix]

i usually say it will have to be a surface mount if you insist on that wall. the client then goes for another location.

 

[oldtimer]

Could be worse I was asked to replace a transformer on a downlight and yep the cieling was L&P and yep it was B$%£2

 

[Sparky Ninja]

I tend to warn them of the inevitability of excess damage being involved, as I will tend to prefer to install a noggin if possible. The best thing is to make the client aware of the risk, then when they are brewing the third or fourth cuppa, knock two bales of crap out of the wall... oops!!

 

[chiplard]

I have done it but only on a few occasions. My tip would be to cut the hole slightly oversized ( obviously no bigger than the socket facia ). Then screw a 1/2" thick batton onto the back box with a 2" screw leaving maybe an inch of wood showing at either side, just start the screw dont tighten on fully. Screw 2 small pieces of the same batton onto the original piece ( onto the bits that stick out either side). This can then be fed into the hole and screwed on through the lath and plaster. Now tighten the back box onto the wood.

 

[nickblake]

What i do is two things first use the deeper drylining box the 47mm ones the other thing i do is i use my fein mulimaster to cut the hole not so much pressure on the hole , another thing you can do is if your there for more than a day is to put the cables in but using some grip fill glue a peice of wood to the ther side of the stud and prop it in place over night then use a deeper back box 47mm again

 

[eckersecker]

Screw to noggins or to the vertical wooden frames in the wall.

 

[Deleted member 26818]

I try to place my hole next to a stud if possible. Gives it a bit of support when cutting out, and something to screw into through the side of the back box.

 

[Richard]

Fein multimaster is my favourite fr cutting the boxes. Like someone said, try and locate on an upright if possible.

 

[Andyfm]

Tell your customer that the box will have to go next to an upright, if not they cannot have the socket on that wall

 

[ian]

I tend to use my fein mulimaster and cut thr hole next to a stud. It gives the larthe some support. I then fix a piece of wood to the other side and screw a 35mm box between the wood and the stud. Works a treat, just need to be careful, and tell your customer that there will be every chance of damage.

 

[nickblake]

Did one last week cut the hole but putting the back box in the plaster fell off easy then peice of platerboard over the lath and replaster , the biggest thing with lath and plaster is the condition of the plaster if its good you'll have no problem if its perished then its a pig ,90% of the time its perished

 

[poirot]

I line the bottom of the box onto the top of a lathe then cut two lathes up either side with a padsaw then fit a metal box and secure by screwing through the top and bottom side fixing holes into the top and bottom lathes.

 

[Deleted member 9648]

The only really secure way I have found is to cut the hole for the box and then whack a big wad of undercoat plaster in the hole,push the box back into this,square up the edges and leave to go off.Finally trowel up with some multifinish.
You are dependant on there being a back wall for support...ie,a normal partition rather than a big void...and sometimes it may be necessary to wedge some plasterboard up the sides and bottom as well to support the plaster.
The big advantage is that once cut the lathe and plaster is too weak to support the accessory being tightened back and problems are inevitable...with this method the sides of the cutout are fully supported once the plaster has set and it is just as good as a box set into a solid wall.
Not a method which can be done without some redecorating being required,but it wont move.

 

[Marvo]

You could try Sikaflex, it sticks like s**t to a blanket but it does take a good while to set. Plywood packing blocks behind to make the correct depth.

 

[whats an rb4]

expanding foams great