My house was built in 1929 and still has the original hardwood floors. And now some 85 years later they are in terrible shape. They squeak like crazy, many boards are broken and splintered, there are gaps, they are uneven, and there are several places where someone put many nails into it (I assume to try and stop the squeaks).
Refinishing the existing floor is a daunting prospect due to extensive damage, a significant percentage of the boards would need to be replaced.
Making things complicated though is there is no subfloor and all interior walls sit on the hardwood. So the floor was nailed directly to the floor joists, and then all interior walls were put up, I can't even imagine how you would get that floor up and out for under the walls that are nailed through it.
So what can I do? Wall-to-wall carpeting would be the easiest solution, though I'm not crazy about an entire house of carpeting. Is the only other option laminate assuming I can get the floors to be level? Or can I just treat the existing floor as a subfloor and do what I like once I get it level?
Best Answer
Talk to a hardwood installation company. You might be surprised at what they can do with your floor in your budget. It might be too expensive depending on the extent of the damage, but a lot of visual damage is actually acceptable in vintage hardwood floors, and they may be able to replace the bad pieces, resolve the squeak, and refinish the floor for a cost less than the overlay and new flooring would cost.
Otherwise, plan on shoring up the existing flooring as a subfloor:
Add new pieces of wood anywhere there's a gap of more than 3/8" in the floor. If the floor is very uneven with obvious depressions and wear spots, going through with a large floor sander can reduce the unevenness, and produce a level and flat enough floor. There are leveling compounds you can use at this stage, but if you do, choose one that is flexible and will not become brittle. Concrete based compounds are not suitable, as they will crack and pulverize, ultimately becoming ineffective over time.
Take the time to screw the wood to the joists below to reduce the friction noise (squeaking). This might take a significant number of screws and time. If the cause of a squeak is rubbing between two adjacent boards, a short screw in the crack between them can secure them together enough to eliminate the squeak.
Depending on what you want to place on top, add 1/4" luaun or thicker plywood - up to 3/4" underlayment - to resolve the remaining flatness and gap issues, and to meet the needs of the flooring you choose to place over the top. If you're going to put another hardwood floor down, you may not need thick underlayment. If you want to put carpet and pad down, you'll probably want thicker underlayment. Consult your flooring installer or the flooring instructions for the recommended underlayment type.
You may be able to get away without underlayment if you use a thick laminate flooring.