You don’t mention whether the boarded loft is being used for storage or living. If it isn’t, then the easiest solution would be to simply lay blanket insulation over the top of the boards – remembering, of course, to leave a space near the eaves for air to circulate. However, assuming that the loft space is being used for storage, then blanket insulation is obviously not a viable answer.

There’s no reason why boards in your loft should prevent you having either loose-fill or blown-fibre insulation – indeed, both of those types of insulation would lend themselves to boards as a means of keeping the insulation from blowing about. But if the boards in your loft are proper floorboards rather than, say, MDF sheets – and I’d expect that, it being a Victorian house, they’re the real McCoy – then you’re probably looking at blown-fibre insulation and a contractor rather than trying to lift the boards and put in loose-fill insulation yourself.

As for whether you can obtain a grant, you’ll need to check with your local authority – but I’d be very surprised if you’re not eligible for some kind of assistance.