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 below the
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 improve things?