Ren, we are getting quotes on hardwood floor and have been given some conflicting information. One person says the he must put plywood down (I don't think he has checked our 12 year old sub-floor at all). Another person says this is just a "money grab" and that with his technique there is less chance of squeaking. He uses glue and wood screws to attach the hardwood to the joists and original chipboard if the hardwood runs along the joints. We really don't know which is better and would appreciate your opinion.
Answer:
I would not put down the underlayment because it does in effect promote squeaks. I still want the existing sub-floor screwed down properly but adding another level of sheet flooring is not really logical. Neither would I ever permit hardwood flooring to run parallel to the joists underneath it.
