I have been replacing a ceiling light in a bedroom and there is not enough slack in the electric cable to connect to the new light. I'm assuming, from what I've read, that I can attach an extension to the cable - which is accessible in the loft by adding a junction box and additional cable? My question is what cable type do I use for the extended part. I have bought 1.5mm but on reading posts here I'm wondering if this is right. I've also bought a junction box with screws - but am now wondering if that doesn't count as maintenanceless - although it will be accessible in the loft? Help gratefully received