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[citywest]

Has anybody come across this practice before? I live in a purpose built flat with concrete floors and ceiling. The cables for the ring main and the lighting circuit are imbedded into the concrete floors and ceilings with no conduit used apart from besa back boxes which the ceiling roses are screwed to. Was this normal practice? I take it there is no way of rewiring lighting circuit unless using surface trunking? The ceiling slab is reinforced concrete with the thinnest layer of skimming imaginable. The flat was built in the early 1960’s with black outer sheath (quite tough but not rubber) and stranded cable – but it is much bigger than 2.5mm T+E. It looks like 4mm T&E Even the cooker has the same size cable!

[sparx]

Hi they (we) did some strange things back in the 60's (& with the wiring too!) Hi Hi.
It may be what was known as TRS, (tough rubber sheathed) cable probably 7 strands of .029" hence 7/029 or 7/036 or even 7/044, which = 2.5, 4.0, 6.0mm resp.
dont forget most cookers had 1 small oven & 2/3 small rings so larger cables not reqd.
we had this prob. of concrete @ daughters flat & ended up fixing false ceilings Plaster bd over 2*1 tile battens, to meet regs for buried cables wired in Firetuf/fp100, metal sheathed cables for lights/sockets and ran 6mm cooker cable in coving around 'Safe zone'
not easiest way but no way was 'Madam' having mini-trunking!!!!
regards SPARX