Just been looking at some solid wood floor options (and possibly laminate
too, although wood is preferred). Was looking at something along the lines
of the B&Q Select range - not necessarily that particular brand, but that
style of smaller, coated wooden sections.

This is to be laid on top of ground-floor floorboards from front door,
through the hallway and on a small landing.

I've been comparing the different underlays. I don't need a waterproof
membrane as the floor is above an open cellar and not in contact with the
ground (it rests on joists) and the floor surface is quite even, so it'd
just be for noise reduction and further smoothing.

I've seen the cheaper, thinner rolls of white underlay and the more
expensive, thicker, sheets of green stuff. They both seem easy enough to
work with, but will I gain any benefit from the thick stuff? If I go for
wood then that's going to add at least 20mm on to the floor height, I
reckon. Much more than that and the transition to the carpeted lounge area's
going to be rather steep! As long as the new floor feels and sounds solid
underfoot for years to come, I'll be happy.

Thanks.