Best dry lining boxes for lath and plaster wall

[aesmith]

Hi,
As the subject says, I'm looking for thoughts for the best type of boxes for lath and plaster walls. Compared to plasterboard the differences are uneven back surface, quite thick overall, and tendency to crumble around any cut out. Particularly for the last reason I'd rather something that stays put once it's in place, rather than only held secure when the accessory fixing screws are tightened up.

The electricians that did the rewire a few years ago used boxed with screws in each corner, these work OK as long as there's something for the screws to get a grip on at the corner, but rely on a very accurate cut out or there's nothing for the screw to grip.

Suggestions appreciated, Tony S

 

[EFLImpudence]

You will have to make something to which you can fix a metal back box, or

attach (gripfill) two pieces of, say, plywood to the rear sides of the lathe and plaster hole in order to use a plasterboard box.

 

[aesmith]

Thanks. Will have to have a look behind the surface. In the upstairs rooms where there's a void behind I could possibly bridge between stud to make a surface to mount a metal box. That would leave the cut edges of the plaster unsupported though, unless I plastered them into box making it a permanent fit. Maybe the second suggestion would be better, although that would make it very thick.

 

[EFLImpudence]

......

 

[Lectrician]

Find an upright, notch into that 2/3 to one side of double back box.

 

[333rocky333]

you may be able to fix these to the lathes then fill over the tabs
https://www.ukelectricalsupplies.co...MI5rjQ6fn11gIVp7DtCh16vAVkEAQYAiABEgJ-cvD_BwE

 

[Jackrae]

If your lath and plaster is anything like I have you won't have a flat surface on the backside of the lath to fit the dwangs onto. My method in such circumstances is to fit a wooden 'foundation' block to the stone/brick wall using either screws or gripfill. Once that is secure, fit suitable thickness of filler pieces to suit depth of box, fit box and make good plaster to box edges.

 

[sparkwright]

Finding a stud, notching it, and fitting a metal box is the easiest and best way.

A noggin can also be fitted between two studs, again with a metal box, but this will cause a lot of damage.

I've found Appleby dry-line boxes can be bodged about with to fit on a lath and plaster wall, if the hole is neatly cut out, but this is not the best way of doing things.

 

[JohnW2]

If your lath and plaster is anything like I have you won't have a flat surface on the backside of the lath to fit the dwangs onto. My method in such circumstances is to fit a wooden 'foundation' block to the stone/brick wall using either screws or gripfill....

Would it not be very unusual to have a 'stone/brick wall' beneath lath and plaster - or am I misunderstanding you?

Kind Regards, John

 

[Jackrae]

Would it not be very unusual to have a 'stone/brick wall' beneath lath and plaster - or am I misunderstanding you?

Kind Regards, John

Scottish house building technique for older buildings - walls in stone, vertical studs (2" x 2") fixed to walls using "dooks" then horizontal laths nailed to studs. This gives a 2" gap up between the lath and the wall to act as a vented damp barrier. The precursor to brick-built cavity wall. We were eons ahead of our southern counterparts

Edit : Should have added that, because of inevitable unevenness of the stone wall inner surface, the vertical battens invariably stand away from the wall surface, apart from minimising them 'drawing' damp it also offers the opportunity for running cables between devices via the gaps

 

[aesmith]

Scottish house building technique for older buildings ...

External walls are exactly as you say, apart from those upstairs that have a crawl space in the eves behind them.

 

[JohnW2]

Scottish house building technique for older buildings - walls in stone, vertical studs (2" x 2") fixed to walls using "dooks" then horizontal laths nailed to studs. This gives a 2" gap up between the lath and the wall to act as a vented damp barrier. The precursor to brick-built cavity wall. We were eons ahead of our southern counterparts

Interesting - not something I have often come across in England, although I have lived with (and have had to deal with) many an internal stud wall with lath/plaster on both sides of the studs, as well as lath/plaster ceilings.

I have used an adaptation of the method you describe on walls with lath/plaster on both sides - by attaching a 'foundation' block of wood to the inside of the laths on the other side of the wall (after breaking off the worst of the protruding bits of plaster - using either glue (like Gripfill etc.) or expanding PU foam.

Kind Regards, John

 

[Iggifer]

Would it not be very unusual to have a 'stone/brick wall' beneath lath and plaster - or am I misunderstanding you?

Kind Regards, John

i cut into a lath and plaster wall recently to find wattle and daub behind it

 

[JohnW2]

i cut into a lath and plaster wall recently to find wattle and daub behind it

Funny you should say that, since one of the walls of my house is partially like that (although some of the wattle/daub has been replaced with rendered brick infill over the decades - so is now like the Scottish arrangement that has been described).

Kind Regards, John

 

[Lectrician]

Interesting - not something I have often come across in England, although I have lived with (and have had to deal with) many an internal stud wall with lath/plaster on both sides of the studs, as well as lath/plaster ceilings.

I have used an adaptation of the method you describe on walls with lath/plaster on both sides - by attaching a 'foundation' block of wood to the inside of the laths on the other side of the wall (after breaking off the worst of the protruding bits of plaster - using either glue (like Gripfill etc.) or expanding PU foam.

Kind Regards, John

Down in Devon we have lots of older houses which have lathe and plaster on external walls, often a 2" or 4" batten on the wall, or stood from the wall. Very varying depths from wall front to stone wall behind. In these cases I have found either 47mm, 35mm or 25mm metal boxes fixed to the wall or on battens fixed to the wall in various combinations works well.