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?

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    What is it under this floor? If you ask me that is the crucial question. Solution depends a lot on this information. Also is it a ground floor or upstairs? Mar 5, 2015 at 10:55
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    One other thing: you can change floor that's for sure; but first things first we must know what is under it? Mar 5, 2015 at 10:57
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    The only thing under the hardwood is floor joists. My question applies to both a ground floor and second floor, however the ground floor is in much worse shape and a much higher priority. Mar 5, 2015 at 17:42

8 Answers 8


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.


Yes you can use the existing floor as a subfloor, but I humbly submit, that the brittle cement based self leveling underlayment would not do well sandwiched between two wood surfaces, and a slew of fasteners driven through it. I seems to me the vibration, the fastener shooting through the cement would start cracking up the poured underlayment. I believe it is done a lot as a standard operating procedure, so it is accepted. I would not want a bunch of cement chips holding up my floor. But once it is done, it is always out of sight, out of mind, I guess has been the norm too. I am not trying to slam anybody out there, I see that the accepted "norms" are changing. If I am wrong please say so.

If your floor is under the interior walls and most of the damage is in the middle of the rooms where all the foot traffic has been, and you know your existing floor is 3/4", I would cut out the sections of damaged floor and leave the existing intact flooring, as much as possible, to pass under the walls. Wall supported by joists (perpendicular) are not as critical, you can remove the flooring as close to the wall as you like. It's the flooring where the walls are supported in the direction with the joists. Keep the existing flooring intact for at least two joist spans and cut out the rest, replacing it with 3/4" CDX for 16" centers or 3/4" T&G for 24" centers. You could use T&G for all of too if you like. If your existing flooring is 7/8" or 1" thick, add an appropriate shim on the joists before you lay the new subfloor. Where the plywood meets the second joist back from the parallel wall, at minimum, add a 2X4 nailer, slightly elevated to make the new and old surfaces flush. Glue the nailer in place, using screws or nails to hold it until the glue sets.

Using an adaptation of this process, you can even flatten the floors a bit while the damaged floor is up, you could sister the existing joists with 2X4's to eliminate the sag that the existing joists have created over their years of service. You will not need to add the shims then, just raise the sistered joists high enough to make up the difference in the thicknesses as well as creating a new flat surface. A scrap of 3/4" plywood will set the ends right, and a string line through the middle, raised slightly above the nailers at the ends will get the center of the room flat. There is a little more to it, but I am trying to keep from writing a novel. This should get you going in the right direction.

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    And yet you are probably surrounded on three sides by the same material, with nails or screws driven through it. There is a reason that gypsum cement (pretty much the same thing as the middle of drywall) is used for this application, not a portland cement-based product.
    – Ecnerwal
    Mar 4, 2015 at 18:30
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    Since I am only familiar with the cement based self leveling underlayment, which is obviously not gypsum based, is it safe to presume that the nature of gypsum based levelers, which I think are only trowel grade, can handle the nails driving through it with out having chunks flying out with the flooring nails being driven at an angle? It sounds to me like a prime candidate for chips to get dislodged and getting up under the flooring that is just been laid. Can't see it, the flooring paper is hiding it. There is the movement between each piece of the original floor too. Sorry about the running
    – Jack
    Mar 4, 2015 at 19:49
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    Patent, US004075374, page 7, column 2, lines 22-25: When fully dried, nails or other fasteners can be driven through the poured floor into the subfloor without causing the poured floor to chip or crack or otherwise deform. In short, you're making up a problem that does not exist in practice. Pure F.U.D.
    – Ecnerwal
    Mar 4, 2015 at 20:16
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    I wouldn't trust a patent to be a reliable source of information. It's only someone's idea that they hoped to profit from. There's nothing in the patent process that says the idea has to work. The expert reviewer is mostly looking for duplicates, not feasibility.
    – AaronD
    Mar 4, 2015 at 22:00
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    But, if you know that a patent refers to something that is independently known to work, then it can be useful.
    – AaronD
    Mar 4, 2015 at 22:01

can I just treat the existing floor as a subfloor and do what I like once I get it level?

Got it in one. Look at gypsum cement "self leveling" floor compound for one approach. "self leveling underlayment" is another name of a product with similar applicability.

If, like @Jack, you are afraid of nailing though it (not a problem with the right product, can be a problem with the wrong product), you can use either a floating or a glue-down approach for a (usually "engineered") wood floor surface. I myself have a good deal of glued-down solid-wood parquet flooring - quite nice, but not as easily/cheaply available now as it was before laminate floors came on the market, which is a pity.

Once the acrylic adhesives (low VOC) came on the market solid-wood parquet was a joy to work with - the old solvent method was not much fun (stank to high heaven and had very rigid timing to follow. Stressful.)

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    Don't know if a self leveling product would be a good fit here because of the gaps. Mar 4, 2015 at 16:37
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    Easy enough to tape or caulk the gaps before underlayment.
    – Ecnerwal
    Mar 4, 2015 at 18:28

In addition to the prospect of using the existing flooring as a subfloor with adequate leveling, which would be suitable for basically everything besides tile, you could additionally add lay 3/4" plywood over it to make that a new subfloor, and then lay tile or any other kind of flooring you want over it.


What you're describing sounds similar to my parents house. They had a thin layer of plywood (1/4"?) installed over the original hardwood floor to level it, and then put a new hardwood floor on top of that with the new boards laid perpendicular to the original flooring. It's been a half dozen years since the work was done, and the new floor is still completely level and non-creaky.


If your ceiling height allows it I would screw down 3/4 plywood over the existing flooring (after screwing down all the creaky pieces I could find) and then put down wood flooring over that.

I would skip over the self-leveling products as much as possible.

  • why 3/4" plywood instead of something closer to 3/8"?
    – warren
    Mar 11, 2015 at 13:34
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    3/4" plywood is standard for flooring. Chances are some of the wood flooring is cupped or warped and the 3/8 would "transfer" some of those problems. It would be better to pay a little more and eliminate any potential problems.
    – Mayo
    Mar 11, 2015 at 14:11

First on squeaking: Try to figure out what the cause of the squeaking is before trying to fix it. I advise you at least figure out the cause before putting in a new floor on top of the old one, as access to the old floor may be helpful. Most common cause for squeaking (as far as I know) is that the floorboards aren't fastened perfectly to the joist anymore and can move when you walk on them. This can be fixed by screwing them into the joist (from above) or shimming (from below). Given the weirdness of your interior walls, the squeaking could also be caused by having the floorboards bent under stress. In that case you could remove the source of the stress (for example the walls) or add support to the floorboards. Whether this is a problem depends on the strength of your floorboards and the stress placed on them. I had this for example with an aluminum frame interior wall that was fit too tightly so it pushed up the floorboards.

I had a similar problem to yours, except that my existing floor wasn't as damaged. I sanded my floor level, treated it against bugs (just to be on the safe side) and then put laminate on top of it. The laminate placed perpendicular to the existing floor. This was enough to solve the squeaking and give me a nice new floor. Sanding it made it level enough to support the laminate without additional leveling agents (I checked this with the supplier).

So if your floor is level enough, you could try the same.


Ok, since you said that only floor joists are under floor, I’m guessing that they are lied down in a layer of sand? If that is the case you have more problems than bad wooden floor. Firstly, I don't suggest that you put anything over existing floor, because it is like building house on a poor foundation, every new floor will sunk down together with its "foundation"-existing floor. Since you said that floor goes under the walls, that’s not really mayor problem: you just take grinder or similar tool and cut the floor on the edge of the wall. This maybe takes some skill, but can be done. Then, for the ground floor: if you don't have concrete slab under floor joists you should pour some gravel, compact it, then pour reinforced concrete slab (10-15 cm thick 4-6 inches),then apply some hydro insulation coating. Next layer is thermal insulation (Styrofoam 5cm 2 inches),and on top of that cement screed (round 5 cm 2inches).Than you can put whatever floor you like, doesn't really matter. Now, if you have a concrete slab on the ground it is easier; assuming that slab is kolas no craks, slopes etc. If not I suggest that you put insolation layers and cement screed. For the upper floor it is even simpler: cut the floor like I explained; most likely you have a screed under, and then just replace with new one...If you have any questions just ask.

  • Oh sorry, I didn't understand your question earlier. Under the ground floor there is a full basement, concrete block with a poured floor. Mar 9, 2015 at 15:28
  • Well, great then.....it's much easier that way. I have seen houses where floor joists were placed in a sand, that's why I asked.... Mar 9, 2015 at 15:31

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