Have got a 1.4 kg gammon joint

[Saltire]

which we got before christmas, it's been inf reezer. The instructions say to boil for 1.5 hours. However, i don't like boiled gammon and tend to jsut roast. Do i really need to boil it

I part boil, part roast. Boiling removes some of the saltiness then you can score the fat and baste it before roasting for the remaining time.

I have now got it in a big pan of cold water on the hob. How long do I boil for? and then how long do I roast for?

I'd do an hour boiling then 30-45 mins in oven

Don't boil all the time, simmer gently once brought up to boil with some black pepercorns, carrot, celery, parsley, onion quartered for the correct time.

Then take off skin, score fat and then put some cloves into the fat and roast for the remaining time. You could put some marmalade on the fat or honey and mustard. Cooking times are 25 minutes for 450g of gammon.
I would then stick into a hot oven to about gas mark 7 and roast for about 15-20 minutes.

You can just roast the whole thing but don't take off the skin until about 15 minutes before the end of the cooking time, cover with foil until then. Then apply the cloves, honey, mustard or whatever you fancy.