On 30/07/2019 23:06, Mathew Newton wrote:
On Saturday, 27 July 2019 16:26:00 UTC+1, ARW wrote:
On 26/07/2019 22:50, Jim K.. wrote:
Mike Clarke Wrote in message:
On 25/07/2019 21:56, Harry Bloomfield wrote:

If a box is proud, a plasterer will tend to make the plaster deeper just
around the box to get cover, which will show in the finished job. I've
seen it many times.

But the OPs boxes are only 1 - 2 mm proud of the plasterboard. Assuming
that there's to be a 3mm skim then they'll be 2 - 1 mm below the
finished surface of the plaster and there should be no need for the
plasterer to build up extra thickness at the boxes.


Ah finally ! A voice of reason :-)


You cannot reason with a plaster.

And on that basis I figured I might as well make the possibly-an-issue-possibly-not into a simple non-issue and went round the boxes I'd done so far and sunk them into the blocks slightly so they are no longer sitting even the slightest bit proud. The blocks were smooth and a so a bit tricky to scrap off just a mm or two but I found the easiest/quickets way was to roughen up the surface with a scutch chisel and then scrape this roughness off with a straight chisel to provide the required recess.

Depending upon the type of block, other ways can be easier, but messier.
When building our conservatory, the dwarf walls and partial full-height
walls were built with lightweight blocks on the inside and a router with
an old bit made short work of recessing back boxes and chasing cables
into the walls.

SteveW