Fixing to PLASTER AND LATH

[STI]

Can anyone advise on how to fasten anything to a plaster and lath wall, Its very old and basically I am trying to put a surface mount flex outlet on the wall and i cant get a grip. I have tried plaster board plugs and the special screws that grip the wall and then expand behind it. Nothing has worked. The special fixings just cut throgh the thin (mm) thick plaster. For the FCU/flex outlet I could resort to grip fill but my problem is the FCU is for a panel heater which will also need to fasten to the wall. The position of the heater may exclude the use of any battens in the wall.

So can any one offer any advise on fixings to use. I have thought of dib and dob a piece of plaster board onto the wall and fixing to this but thought i would ask here first.
Thanks

 

[RMS]

You could try and cut a hole out behind the heater and slide wooden battens into the cavity and screw through the plaster and lath wall to secure the wood. Make good and fix the heater or brackets.

In my experience I can normally get a good enough fixing for a patteress through the lats. You could try to drill holes carefully and plug it, maybe even apply a small bit of grip fill to bond the plug in the wall.

 

[bernardgreen]

Cut a hole in the lath and plaster about the size of the box you are going to fit. Through this slide a piece of timber behind the lath and plaster and adjust it so its centre is behind the hole.

Try it for size to find how large the timber can be to fit between the vertical timbers behind the lath and plaster. Tie a string to a hole at one end so it can be recovered if dropped. Once you know the size drill a hole for the cables where the box will be fitted.

Then either screw through the lath and plaster and into this timber to hold it in place. Or use thick adhesive to glue it to the back of the lath and plaster. Or both. Often a few screws that go through laths and screw till the head is on the lath will hold it firmly. It will be necesary to fill in over the screw heads. Use plywood to fill the hole if the box has to surface mounted.

Or use two pieces of timber side by side or one above the other with a pre-cut square hole into which a dry liner box can be fitted.

 

[ricicle]

Sometimes longer or thicker screws are enough to force a reasonable fixing on the lathes. But if they are all broken away then follow the suggestions above.

 

[sparkwright]

Just fix to the wooden laths. These run horizontally, with about a 8 mm gap between each one.

Alternatively find a vertical upright stud (joist) to fix to.

Alternatively try cavity spring toggle fixings.

 

[STI]

Thanks all for the replies. The lath's have come away from the plaster skin this is giving the 2 problems, i cant get a grip to drill/screw into the wood it just gives and this in turn leaves the plaster so thin nothing there to hold the plug or take the pressure of a grip screw. I will try the spring screws.

If this fails do you think that the cut and place wood behind and drill into that be better(easier)for the frame for the panel heater rather than sticking a piece of plaster board of the right size on the existing wall which will be hidden by the heater, and drilling into that ?

Thanks

 

[pjcomp]

Won't help to stick plasterboard to the existing wall - the wall is already weak, so the plasterboard will just pull away from it, or pull the wall with it! And the plasterboard by itself won't be man enough to hold the heater if the wall behind it isn't strong enough for the plasterboard ...

As above, either find the uprights and screw to that, try one of the othe methods of getting strength into the wall, or go for the nuclear option - cut away a section of lath and plaster exposing the uprights, fix your plasterboard to the uprights (with some batten strengtheners behind for belt and braces approach), reskim the plasterbaord, and then fix your heater.

Bit drastic, but from the sound of it your wall will give way once the heater's up, and you could end up spending more time and effort repairing and patching an unsatisfactory job.

PJ

 

[Sherbertlion]

go for the nuclear option - cut away a section of lath and plaster exposing the uprights, fix your plasterboard to the uprights (with some batten strengtheners behind for belt and braces approach), reskim the plasterbaord, and then fix your heater.

Bit drastic, but from the sound of it your wall will give way once the heater's up, and you could end up spending more time and effort repairing and patching an unsatisfactory job.

PJ

I reckon just cut your losses and go for the above. Will depress you to start with, but you'll be assured of a decent job and proper fixings that you shouldn't have to re-do.

 

[STI]

b*gg*r

 

[sparkwright]

Try and send some pictures. The wall may not be as shot as it seems.

 

[flameport]

The lath's have come away from the plaster skin

In that case the wall is totally ruined. Only a matter of time before the plaster crumbles and the whole lot falls off.
Replace with plasterboard now - it will have to be done soon anyway.

 

[skenk]

Spring toggles between 2 laths

 

[JohnD]

nah, fix to the studwork. Try to find a stud by tapping, then drill a small test hole and poke a bit of stiff wire in to work out where it is.

If your screw is into timber stud, it will hold even if the laths fall off.

If you ever want to fix anything big like a radiator, fix battens or a piece of ply to span at least two studs, and fix to that.

 

[bernardgreen]

If this is a very old wall or there has been a history of damp and cold in the property it is possible the laths have decayed to become little more than fibres re-inforcing plaster. In which case the plaster is providing 90% of the strength of the wall and fitting any weight to the wall and depending on the plaster to support it is high risk. Back boxes for sockets and switches will ( probably ) be OK but any weight hung on the plaster and fibre will eventually rip out of the plaster.

So best advice is use the studs but also check these are in good condition and able to take the weight.

 

[STI]

Well Wednesday is the day. Am going to try the studs and toggles as the frame for the heater wont span two studs so hopefully a combination of the 2 will work. Bernardgreen youve hit my main concern, the radiator is 6kg so hopefully finding a stud will be a) possible and B) sfficiently strong for the rad.

Fingers crossed.