I’m getting ready to put down a new floor. I’ve taken up the old floor and the underlayment, and am down to the subfloor (hope I’m using these terms correctly). I have squeaks galore to deal with.
I’m planning to put down new 3/4″ underlayment, glued and screwed with screws long enough to go into the joists below. Then I’m adding 3/4″ hardwood flooring. There is an unfinished basement underneath the whole floor, so I have access from below if I still have squeaks when I’m done.
Given all this, I was thinking that I should not worry about trying to fix my squeaks before I put down the new floor.
Does this make sense?
Replies
I'm not really sure, but just before screwing the new underlayment, I would try to go underneath and force some glue between the old subfloor and the joists. If nothing else, the glue would stop the rubbing between the two, which is probably where the squeaks are coming from. I guess you could hope that the screws through to the joists from the new underlayment will hold everything tight enough, but I have my doubts. See what others say, but I would probably not glue the underlayment and put something like tar paper or rosin paper between it and the subfloor to also prevent squeaks. I know from experience that replacing underlayment that has been glued to the subfloor is a real pain! At any rate, use deck screws, not drywall screws!
BTW, now is the time also to make sure that the floor is sturdy enough and joists are not deflecting too much and floor is not bouncy, etc.
Go to the basement and squirt a good polyurethane adhesive into any spaces that you can see between the joiosts and the subfloor. PL Premium is a good one. Liquid Nails is not suitable cuz it sets too fast. You need to have time to squirt adhesive, then go back upstairs and sink screws. Might be a good idea to get help.
After the subfloor is glkued and screwed tight, lay the underlayment. 3/4" Advantech is a good choice, or Plytanium.When you install it, don't try to get screws through the subfloor and into the joists. Just screw the top layer to the bottom layer. Stagger the joints.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Why wouldn't I want to put screws down into the joists?
I don't even have to read this post (although I did) before saying: Fix the squeaks now. You are down to the subfloor right now, best to address the squeaks while you have the floor partially opened up, rather than waiting until after you add more wood on top, adding more factors to the equation.
I have my doubts about trying to squeeze construction adhesive into the gap between subfloor and floor joists. The best answer (and worst news) is that you should probably take this opportunity to remove the old subfloor, stripping the floor right down to the joists. Otherwise you are adding expensive new flooring on top of something that will still be causing squeaks. That's the kind of thing that will sour the whole project because it won't be perfect when you are finished.
At least consider stripping down the joists, you are already close...and if you have squeaks it's a good indication that there probably isn't any glue holding the panels down, so the old subfloor will come up pretty easily.
...if you do go this route, then we can give you lots of good advice on how to install the subfloor squeak free in the first place.
Justin Fink - FHB Editorial
> I have my doubts about trying to squeeze construction adhesive into the gap between subfloor and floor joists. The best answer (and worst news) is that you should probably take this opportunity to remove the old subfloor, stripping the floor right down to the joists.
If the subfloor material is OK, how about just pushing it up maybe 1/2" to get an accessible gap, squeeze in the adhesive, and drive it back down again? If the nails are ring shank, or the heads pull thru, that won't work. But given that it squeeks all over, that's not likely.
-- J.S.
I suppose that could work John, but wouldn't you be nervous about lifting the subfloor up and possibly causing other problems? I realize the attraction of working with what is already there, but you could also rip it up, and then just apply that 3/4" ply right over the joists, instead of over a (possibly) shoddy, and definitly squeaky existing subfloor.Justin Fink - FHB Editorial
To me, the biggest problem with removing the sub-floor is where the sheets of ply go under walls. Sure, you can run a saw along the wall and cut it loose, byut then you have to provide somew way to support the ends of the new plywood. And of course DW is going to get impatient just as the first piece of old ply is pulled up ...
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
I'm sorry, but I don't recognize DW. What is that?
DW = dear wife aka The Boss
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Oh. Well, I guess I have to worry about the DH then.
I recently had the same dilemma as you, and I opted for an entirely new subfloor. If you have that many squeaks, then odds are you have no glue between the subfloor and the glue. And if you opt to try and fix the sqeuaks, you will find that it will be an ongoing thing and the dynamics of the squeaks will change once you put down the wood flooring. Use your circular saw and set it to depth and cut the old floor out. You'll be surprised at how easily it will come out ( I used a wonderbar and framing hammer after cutting and removed 800 square feet worth of subfloor all by myself, in one day. Make sure you use at least 3/4" plywood for the new subfloor, something like plytanium or advantech would be best, but whatever you use make sure it is tongue and groove, and dont forget to stagger the joints at least 16" ( the closer to 4 ft stagger on a 4X8 sheet the better). Fasten each sheet of plywood by using a quart caulk gun and a generous amount of PL400 construction adhesive ( a case of 12 tubes will only run you about 40 - 50 dollars and then get yourself some deck screws ( I would recommend 3 inchers), deckmates would be fine but the bits that come with those sometimes wear out after a while, if they do ( or what you might find better) is to use #2 square bits. Screw maybe every 12 inches or so, and use a chalk line or laser line as you glue joists and drop sheets to speed up the screwing so you reduce misses. I can almost promise you that you will not have any squeaks anywhere ( I couldnt detect a single squeak in mine) and pay close attention to whether your floor has too much float, or bounciness, afterwards. If so block up down below, or run at least 1X4, maybe even 2X4 furring stips perpendicular to the joists down below, and again I would use deckmates. Wether or not you use furring strips vs blocks if needed, factor your decision based on (1) if you plan to finish the basement and (2) if so, how high your ceiling will be down there and will you install a grid ceiling ( which I highly recommend). If you opt not to replace the subfloor and go the 3/4" underlayment route on top of the existing, glue the crap out of it ( at least 1 tube of PL400 per 4x8 sheet, and you will have to put a ton of screws in, at least every six inches across the board. I venture to say that putting that many ( shorter) deckmate screws in will take you almost as long as it would to just cut out the old subfloor. And then you still have to fix the squeaks BEFORE you even start. Good luck and happy holidays
If you want to get rid of all the squeaks, you've got to pull up the subfloor. You won't be able to get them all out later. One house we lived in had a lot and I fought with them periodically for years. Once you get a bunch fixed, another set will start up. If you're not talking about a kitchen with cabinets and an island it shouldn't be a terrible job. A little scary maybe, if you haven't done much of this kind of work, but not too bad. Don't forget supporting blockers between the floor joists for the ends of the new plywood.
So what do I do about the pieces of the subfloor that run under the bottom plates?
"So what do I do about the pieces of the subfloor that run under the bottom plates?"Leave them in because you will be creating a lot more work for yourself because you will have to support the wall and then reframe that whole area under the wall to support the wall and frame for nailers for the sunfloor. It's not worth it unless the subfloor was rotted beyond repair or damaged some how and I don't think that's your case. Just pull the nails out and cut the subfloor 1/2 way on the joist and butt the new subfloor up to that. If you are not going to take off the subfloor than nail or screw off the entire subfloor first. Once you nail the whole floor off there could be some loose nails from when it was nailed in the beginning, then just pull the nails out.Joe Carola
Edited 12/10/2005 9:06 am ET by Framer
Fix the squeaks now!
Even though the amount of squeaks might seem overwhelming, they are most manageable when it's open. You'll have to hunt down each offending nail, one at a time. It will be good fun.
Sometimes the nails are squeaking that go through the plates of the walls. Cut them with a sawzall.
blue
I think it's good to find out what's causing the squeeks while you have all your options open. They're not always due to simple "bouncing" on the nails -- sometimes it's two edges of subfloor rubbing against each other, the floor rising and falling relative to a partition wall, etc.
Besides, screwing down the subfloor is much more reliable/secure than anything you can do from below (though it certainly doesn't hurt to do both).
happy?
Oh, BTW, map out where the joists are and mark them on the subfloor. Transfer the markings to the edges of the underlayment as you lay it. Will save "air screws" if the joists are the least bit wonky.
happy?
Be aware that your squeaks may be coming from bridging or blocking between the joists. Personally I think bridging and blocking causes more problems than it solves, although for very deep joists (> 2x12) it may be required.
Another big squeak offender are 'shiners' or nails that just missed the joist but are touching the side of the joist lumber. They squeak as the improperly fastened subfloor sheathing goes up and down.
Really though I think the main reason for subfloor squeaks is not enough glue, and I have found that satisfactory results can be obtained using a lot of glue and ring shank nails. Since you already have problems though, go with screws.
OMG!!! - I said the N-A-I-L word!!!! the local screw freaks are gonna have a field day!!! :-)
The last time I screwd a subfloor down was about 7 years ago.Joe Carola
That's what I'm saying...