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!