I have damaged the 6mm cable to our shower which runs accross the loft.
Whilst it has not blown the fuse, which i have now taken out it does not look safe.
Is it o.k to just cut and rejoin the cable using a 30amp junction box?
If it is accessible then yes. If not accessible then will need to be crimped. With the latter normal to used shrink sleeve over whole job. But I would never send someone to do a job like that without first seeing it and it may be not the best option.