2.55mm or 1.5mm

[steq184]

I have 50mtrs of 2.5mm twin and earth on a reel in the shed, now I am going to extend some of the lighting cable via junction boxes in the loft as am having new insulation fitted and this time want my cables above the insulation as advised.
My question is will there be a problem with me using the 2.5mm cable to do this instead of 15mm as original?
Help greatly appreciated.

 

[steq184]

Just decided to go and buy 1.5mm after all......only £13 from Screwfix!!!!

 

[xr4x4]

Good call, 2.5 mm is a pain wiring into lighting fittings.

 

[riveralt]

Just decided to go and buy 1.5mm after all......only £13 from Screwfix!!!!

I think that is for 25m - cannot understand why you are going for 1.5mm when 1.00mm is more than adequate for lighting unless your totally wrapping it in insulation.