On Apr 23, 9:47 pm, wrote:
Is there any reason why I wouldn't want to use either 1/4-inch lauan
or hardboard as underlayment for 3/4-inch oak flooring strips
(nailed)? The subfloor is 3/4-inch OSB with somewhat rough, uneven
surface and hardened glue in some places, which is why I want to put
down an underlayment to provide a more even surface for the finish
floor. I know I could use 1/4-inch plywood, but that is a little more
expensive than both the lauan and the hardboard. But if there's a good
reason not to use one or both then I will spend the extra money for
the plywood to ensure a solid installation. Also, what is the
recommended way of attaching 1/4-inch underlayment to the OSB
subfloor? I think the 7/8-inch staples I already have would be the
quickest - is that okay? Thanks!

Wouldn't it be a whole lot easier to just pull up the crumble board
and put down some decent plywood? The nail holding power would improve
a bunch and the subfloor (with care) could be dead level. Door bottoms
would not have to be shortened and there may be other advantages as
well, like no squeaks, less bounce, etc. Just wondering...

Joe