Need to pass the two 2.5mm^2 cables of a ring main through a 25mm hole
in a 90mm timber joist.
The installation methods in IEE regs (table 4A) don't mention timber.
What reference method does this count as?
Are the cables counted as touching or bunched?
What is concerning me is that if method 4 (enclosed in conduit in
thermally insulated wall) applies, then the rating falls to 16A (ie
20A limit for a ring).
It would be possible to insert a separator (eg a piece of plastic
trunking) to keep the cables about 1.2x De apart, but would that