Electrical chases and ceiling coving?

[Tim S]

Hi, not dead (yet) - just been tied up :)

(I hope this works - just put this new "Gallery2" software on my web server)

Anyway:

I've just stripped the walls prior to chasing in for electrical runs (lovely yellow paint!)

I was wondering what to do with the coving that you will be able to just see at the top of the wall (I want to keep it):

a) I could either try to use a cranked SDS chasing chisel to chase up behind the coving, with no hope of plastering in that last 3 inches - using conduit so this doesn't seem to be a big problem...

b) Cut out a small section of coving, chase and replaster, then stick the coving section back and try to make it good.

What would you do? I'm veering towards a)...

Option c) which is to pull off all the coving and replace seems wasteful and extra work - it's decent plaster coving up there, not polystyrene.

Thoughts gratefully received...

*****

On an aside:

Here's a 30 quid mixer I got off a mate:

to the leg being rotton, it was a bit wobbly (it's heavy, so wobbly is quite dangerous, as in fall over and kill a kid dangerous) - so Mr Heath and Mr Robinson came up with the idea of setting the leg in a plant pot of concrete to give some stability :)

*****

On another aside...

And for what it's worth, those floorheater.co.uk underfloor heating panels I was wittering on about a few weeks back:

Well, here's a test sample fitted, to see how strong it all is:

quite tough - I can't dislodge any tiles nor the polystryrene panel from the floor. One comment I have to make is that the tiles are no longer sitting on a solid substrate as they might be if glued down to screed on concrete. I used a small rubber mallet to give them some abuse and managed to make a hairline crack in one. Granted they are thin tiles, but the reason it cracked is because the UFH panel is quite elastic.

Translating this into a real application, I could see that dropping something heavy onto a floor lined with this type of UFH panel might crack the tiles, whereas they'd probably survive is mounted conventionally...

But this is why we do tests on samples :)

Cheers

Tim

[John Rumm]

Glad to hear you got free! (well depends on who tied you up and why I suppose ;-)

That is usually the way to go. There are variations on this theme:

b) Cut out a small section of coving, chase and replaster, then stick the

Seems like hard work - and chances are you will always see the result.

Hmmm nice ;-)

(I think this is one of the uses for bits of scrap and an arc welder!)

A thicker bed of tile adhesive could mitigate here. Failing that you need include an assessment of the likely reduction in losses of the things being dropped! (i.e. if something expensive bounces rather than breaks, you may be better off foking out for a new tile!)

[Dave Plowman (News)]

Remove enough plaster carefully below it to get a drill in as parallel to the wall as possible and carefully and slowly drill up behind it. The carefully is because a nice old cornice is well worth preserving. Although the plaster they're made of doesn't seem to go 'live' like normal old stuff.

[geraldthehamster]

Can you get to it from above, by removing some flooring? Possibly it might be easier to drill downwards, rather than upwards. You could go into the plaster and the wall behind the coving, then drill a hole beneath the coving to meet up with it.

Regards Richard

[john]

Did lots like that, no problems. Lounge and study had 20" of fancy plasterwork, so wall lights come UP from the floor. Switches as well. An Alidil wall chaser would have been supremely handy!.

[Tim S]

Thanks everyone!

I think I'll give it a go with my cranked chisel bit, maybe running a drill up first to clear the plaster.

One thing I maybe didn't mention is that most of these chases *may* contain one section of 20mm round conduit for ELV, so the brick needs to be cut too (plaster is about 10mm thick). The cranked chisel will probably do that better under the coving.

However, if it's all too yuk to do that, I could replace the 20mm with

2x16mm oval. It's to do with the fact that the ELV circuits will be wired later and will involve upto 4 cables of more than one type (eg Cat5e/aerial coax/SELV control flex/loudspeaker cable) so I need to allow a bit more conduit space to make sure I can get stuff down easily on demand.

Mind you, thinking about it - as I'm grouping 2-4 euromod positions with a double 13A socket which itself may need a vertical drop, it might be easier just to knock all the plaster off for the full width of a double backbox, lay 4x16mm oval onto the brick and replaster one wide chase rather than several little ones... I think most of my plaster is deep enough for oval, but as usual I expect to be caught out...

Thinking aloud...

I'll come back when I tried some next week...

Cheers

Tim

[ARWadsworth]

Try a) first. It does not matter that there will be no plaster behing the coving covering the wires/conduit.

You might find that you have to put a very small bend into the top of the conduit to get it behind the coving.

Adam