Bought a 30 year old house that has glued, reclaimed oak strip flooring. One room was not floored but carpeted. We want to replace the carpeting with the same type of flooring.
On removing the carpeting, we found 1/4″ plywood screwed with drywall screws every 4″ in a grid pattern on top of the original subfloor. When you initially walk on the floor it sounds like it is “crunching” (sorry, best that I can describe it) throughout the whole room. It isn’t squeaking from the floor joists. After walking over it for some time the sound subsides a fair bit but still noisy.
Could the plywood be de-laminating or ??
Would gluing the oak flooring remedy the noise? The rest of the rooms don’t have this problem even though it appears the same subflooring was used.
If we removed and replaced the 1/4″ plywood and glued the new sheets down, would the original subfloor be compromised by all the empty screw holes or would the new glued plywood support it.
Am hoping both layers of subflooring don’t have to be removed.
Any info or suggestions would be greatly appreciated.
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take up a sheet or two of that plywood. You might find something between it and the subfloor that is making these noises. If you pulled it all, you can then screw down the subfloor b/4 laying the new flooding.
Are you needing to bring this area to a level to match the height for the new flooring?
Yes, I need the 1/4" to match
Yes, I need the 1/4" to match the height.
One reason for your "crunching" would be if there is a significant humidity difference between the room and the space (crawl? basement?) below it. The humidity difference (and, more importantly, "cycling" between humidity levels) would cause the plywood to kind of puff up between screws, and then make noise until it's "tromped down" completely.
I think you may be right. The basement is 4' below grade. We haven't heated the basement year round and in summer it was pretty damp in there. The basement room below the carpeted room has no windows or doors and was the worst for humidity.
We don't really use the basement other than storage so don't want to heat it. Any suggestions on how to keep out the dampness without heating or running a dehumidifier? We do keep the upper floors at 60-63 degrees during winter.
If the basement humidity issue is resolved then what would be your recommendation for the subfloor issue? Will it just correct itself and we can go ahead and just glue the oak flooring down on what is there now or should we be removing/replacing one or both of the subfloor sheets prior to applying the oak ?
It's really hard to predict. I'm guessing that, short of heating the basement like the rest of the house, it would be hard to "stabilize" the situation.
Likely simply putting a new floor over it will help somewhat, by being sort of an insulation layer, but you hate to do that only to discover that the problem is still there and still annoying.
Would applying sheetrock to the celiling in the basement room below help?
All I can say is that it might.
You'll likely never eliminate the effect entirely (short of replacing the flooring). In their attempt to eliminate what presumably was some floor squeeking the previous owners drove so many screws as to create the crunching problem.
One might consider something slightly crazy such as pulling every other screw and drizzling wood glue down the screw holes. But it's hard to say whether this would make it better or worse, and it would complicate things if you then decided to pull and replace the entire layer.
(The screw holes in the bottom layer are no big deal, other than you will inevitably hit some of them when screwing down a new layer, unless you lay out the screw pattern very carefully.)
Hi there,
I agree with Calvin that the sound could be coming from debris trapped between the 1/4" underlay and the subfloor. I have seen/experienced this phenomenom and remedied it by pulling the underlay and vacuuming the subfloor very well before re-laying the underlay. Then screwing the underlay down thoroughly while NOT screwing into the joists. I think in your case, the debris could be creating a void between the layers and stepping on it is what is causing the "crunching". The sand, dirt, grit, etc. is crushing into the wood with every step.
Depending on the size of the room and how many fasteners you would have to pull, you may want to start by just adding a bunch of screws to a particularly "crunchy" sheet and see if that alone solves your issues. Flooring cleats or staples for the reclaimed flooring should pull the layers together a bit too, but I wouldn't count on it, and wouldn't install the finish flooring until all was quiet.
There's approximately 350 drywall screws in each sheet of 1/4 plywood so there isn't much room to add more... lol.
Am I understanding correctly that if I replace the 1/4" ply after cleaning the original subfloor thoroughly that I don't have to worry that the original subfloor is damaged by 350 screw holes that will not have screws in them?
Should I also be glueing this new 1/4" ply with new screws?
Thank you everyone for your responses
Oh boy, that's more than 10 screws per square foot. I still think the issue is the 2 layers have a gap between them despite the amount of screws. Maybe the first round of screws caused the plywood layers to bridge and the additional screws were an attempt to pull things together. It sounds like the job was not professionally done as drywall screws are not the right fastener for the job. Are the 1/4" sheets butted tight to one another? If so, this may be where the crunch sound is coming from - the edges grinding against each other. The short edges should have a 1/8" gap between sheets and the long edges should have a 1/16" or so. As for the integrity of the subfloor given the zillions of sheetrock screws, I would say it is highly unlikely that the tiny screw points could compromise the subfloor. Maybe pull a sheet of the 1/4" that has the crunch happening and see what happens then, does the crunch go away when the 1/4" goes away? If so, then you have alot of work unscrewing sheets. Call some buddies, tell them you have beer, then casually ask them to bring their cordless screw guns, then apologize for ruining their night...
Later, put down new 1/4" with either ring shank nails, staples, or a screw that will set flush without bridging the layers. The only way I would recommend glue would be if it was a mastic that was troweled over the entire subfloor. Beads of construction adhesive will only keep the layers from pulling together tight. Good luck