js.b1 wrote:
On Oct 9, 11:14 pm, "Dave Plowman (News)"
wrote:
In this instance, what is the best way to get a back box out of the wall
without damaging the decoration?

First, hope it was not pushed into a pile of wet plaster, because
plaster holds anything in place better than any screw. Then you might
have the "it might move, lets use cement, SBR, fibreglass flakes or...
epoxy mortar... fischer epoxy fixings". Do not laugh, I have found an
expoxy set backbox in block before now.

Sneak up on the backbox
- Remove the screw, grind off any nail, grind off your finger nails
(hey I got the angle grinder in!)
- Use a HD stanley blade to cut down the box sides so breaking any
bond there, but prefably not the cable.
- If extremely lucky the box will now be loose.

If not...
- Push a thin screwdriver down between plaster & backbox.
- Grind the screwdriver into the wall so you are levering against
brick/block not plaster.
- Bend the screwdriver so the box side folds inwards.
- Bend the screwdriver back into shape or keep for "special tasks".
- If lucky the bond of the box rear to the wall will now be gone.

If not...
- Repeat screwdriver attack on the other sides.
- Eventually the sides will be folded in severely.
- The bond will finally break.

If the box will not fit out through the hole...
- Use the HD stanley blade again to enlarge fractionally.
- The faceplate is larger than the backbox remember.
- Typically it is the corner-fold tabs that prevent easy removal.

Do not yank the box out thinking you are home free.
- If you tilt the box you increase the effective height of the rear.
- Tilting the box on removal rips out the plaster skim at the last
minute.

I suspect wrapping a backbox in masking tape might reduce the surface
bond to the metal so making its future replacement easier. That said,
I always use 25mm for lights, 35mm if any chance of a dimmer, 35mm for
all sockets to provide enough wiring for retermination in the future
and if any chance of grid or wago lever clips I use 47mm. That should
sort out all problems - no doubt they will change the wiring accessory
size :-) MK Grid 2G backboxes of course use 3 holes whereas every
other backbox in the universe (except some cooker) use 4 holes - so
oval/cables will not align :-)

Paper based wallpaper is bad news, because you can never repair it
invisibly.
Vinyl based wallpaper is easy to repair invisibly, just like carpets
avoid hard creases and avoid separating lining paper from the surface.
Likewise layers of lining paper are bad news, hard to repair levels.
Restick wallpaper with proper wallpaper paste.

It is a trial of patience really.

Printed and saved. That sounds an interesting way to do it next time.

Thanks

Dave