thanks for the advice, i think i will go for the 16mm as i don't want the cable to get too warm especially where it goes through the loft and the cheapest i've found 16mm is 43 + vat. if theres any one out there near gnosall in stafford that would give me a price to connect it to the mains...
i have a 10.5 kw showerand need to run a cable some 25 meters one electrician says 10 mm Twin & earth will suffice but others say it should be 16mm. i am led to believe that 10mm goes up to 9.5kw. any advice would be welcome