I agree with Mike - steel conduit is entirely acceptable for use as a c.p.c. - BS 7671 specifically says so in reg 543.2.1 (vi) - that fact that it's concealed shouldn't of itself be more of a worry than the c.p.c. in a concealed length of T&E. If it's lasted that last 36 years without apparent deterioration, it doesn't seem likely it's going to fail catastrophically in the next 5.
I agree with Mike - steel conduit is entirely acceptable for use as a c.p.c. - BS 7671 specifically says so in reg 543.2.1 (vi) - that fact that it's concealed shouldn't of itself be more of a worry than the c.p.c. in a concealed length of T&E. If it's lasted that last 36 years without apparent deterioration, it doesn't seem likely it's going to fail catastrophically in the next 5.
