Wooden floors - do they require underlay?

Lord_Blue

Solid wood flooring should be nailed down and is done as 'hidden' in the side grooves at 45 degrees usually. There seems to be a bit of confusion in this post, so why not look at some instructions for this...

http://www.wood4floors.co.uk/wb/pages/guides-info/fitting-instructions.php

ormus

all wood needs some form of expansion gap. old style floorboards had the gap under the skirting, and between each plank.
modern laminate still needs an expansion gap. and laminate is supposed to be inert.

the glue or nails just contain the wood somewhat. glue tends to be a little flexible and nails do move a bit. but you still need an expansion gap around the edges.