Solid Hardwood, Engineered and Laminate Flooring - Hard wood flooring

I bought the house with hard wood floor 6 years ago and not knowing better did not seal the floors. Now the floors are beginning to squeak in many places. Can't get access to the subfloor from beneath as downstair celing is finished. Does anyone have any ideas on how to fix this short of putting down a new floor?

I'm not so sure your problem is related to not "sealing" the floors. Maybe the floor was not nailed to spec. What was it installed over? Was it a DIY or a pro install floor? Is the floor showing gaps between the boards, or is it tight? Maybe some more info will help find a remedy. I could ask another dozen questions, but this will do for now!
I would hate to think that your only alternative to tering it out would be to top nail the floor, into the joists. Maybe Phil has an idea???

Can you tell if there is underlayment under the flooring ? Can you see to the sub Floor in the gaps? Are there gaps? Does it only squeek in the summer or winter? Need More Input !!!

Phil

Thanks for your replies here is what I could find out. Floor was put in by the builder before we bought the house. The creaks are all over the place year round and one place has a small gap between the boards due to little water damage. I could see no underlament between the subfloor which appears to be plywood and the hardwood floor. This floor is of the short lenght variety, the boards are 2 to 3 ft max. I have a power nailer and I decided to nail a few boards down to see if works, however, nailing one end causes other end to creak lightly. If I nail both ends then the adjoining board begins to make noise in a couple of days. I am begining to believe the the boards were never nailed down properly to begin with. I removed one of the mouldings from the wall and the boards are flush and no gap. I though there should be a small gap to allow for expansion. Please let me know if you need more info and hope you can suggest something to fix the problem. Thanks.

Thanks for the additional info. Unfortunately when a builder does the install you can run into these problems not that there are not builders out there that know what they are doing but in this case they did not. You will not be able to get rid of the creaking because it is caused by the wood on wood with no underlayment to eliminate the wood on wood you will have to live with it unless you remove the floor. I would recomend that you call your builder and have him come back and use a flush trim saw to remove some of the flooring around the perimeter of the room to allow for expansion and contraction this is a must !!!! If there is no room for the wood to expand and contract you can have additional problems with the floor twisting and cupping trying to move. How long have you been in the house ? These are my thoughts on the situation. I'm sorry that it was not good news but at least it will get you started on trying to eliminate future problems with the floor. People sometimes don't realize or care about the importance of using a professional installer for hardwoods in new construction and even remods. Builders always tell them we can do it cheaper than they can but they lack the knowledge that is needed for proper installation practices.

Philly :D