How to stop floor squeaks?

[Bill Space]

Hi all,

I bought the house next door and am in the process of renovating it. It is pretty much a gut it and redo everything. The motivation was to control the four acres it sits on, but the prospect of rental income is enticing.

The floors are oak over diagonally laid subfloor. They squeak. I do not plan to refinish them, but rather to install a floating engineered floor on top of them. But what about the existing squeaks? I am sure they would remain if I do nothing.

So I am thinking of using a bunch of screws to secure the existing hardwood to the subfloor before doing anything further. The existing oak floor is not that great anyway so nothing lost there. Perhaps a screw every 8" in a matrix would solve the problem?

I do not really have a clue As to the best way to approach this.

Any and all advice greatly appreciated. I am retired and this is a kind of hobby project. I can do things that would not be cost effective in the real world. We bought the property out of fear that a bad neighbor could end up there. We do not have enough life left to want to live it frustrated, if you know what I mean.

Anyway, I am doing my best to do a good job on this renovation as if one of my kids could end up living in it, although that is unlikely.

I generally have success thinking outside the box but in this case I really could use some advice.

Thanks!!!

Bill

[Roy Harding]

I understand your motivation(s).

I'd mark out (on the surface of the floor) where the floor joists are, and drive screws like crazy on that line - everywhere. Then, I'd carry on as you plan (installing an engineered floating floor).

[Lee Schierer]

Make sure your screws have a long enough shank to get through the floor and sub floor so the thread will pull down both layers tight against the floor joist.

[Jerry Miner]

In my experience, floor squeaks usually come from the floor or subloor moving against the fasteners. I'm betting that your squeaks are probably from the subfloor moving relative to the fasteners and floor joists. (subfloor is probably nailed straight down. Finish floor is probably toe-nailed). If you're going to screw it down, I suggest you try to screw through the subfloor into the joists. Alternatively, you could crawl underneath and work some construction adhesive into the space between the subloor and joist.

To diagnose better, you could send someone under the house while someone else walks across the floor and locates a squeak. From underneath, you should be able to see (with a light) some movement in the subfloor (You could then, drill a small hole up into the living space to help locate the joist). HTH

[Bill Space]

Greatly appreciate the input so far!

The house has a full basement so
access to the floor joists is easy from below.

I would not have thought to try to concentrate on
having the screws hit the floor joists but that makes
a lot of sense!

Bill

[Tom M King]

I've done it a lot. Get a 12" bit extension for an 18v impact driver, and 5 pound boxes of star drive deckmate screws the right length. The extension will keep your hands under the joists, and make access easier in a bunch of places. You will also need some wedges to shim under the subfloor in some spots. The wedge goes between the subfloor and the joist. I glue the wedges top and bottom. You can usually see space where there is a subfloor nail squeak. Have someone walk on the floor above while you watch underneath. If a wedge won't do it for subfloor board moving on a nail, pepper the floor to the subfloor with screws from underneath.

I've never had to put a screw down from the top, but every floor I've done this on has been in a fairly old, but reasonably valuable houses (1934 University Park, MD.) where they wanted to continue to use the original Oak floors.

[Bill Space]

Tom,

I understand I would use 1.25 inch screws with your method? Assuming 3/4" sub floor and 3/4" flooring?

i see the advantage of going up from below when wanting to keep the existing hardwood flooring, but also see how this could be an advantage even if installing a floating floor on top of the existing hardwood... With the exception of not having the solid connection to the floor joists that screws from above would offer.

Thanks is for your help!

Bill

[Mel Miller]

One of my kids used special screws for this purpose that had a head that you broke off after driving the screw, which left a smaller mark in the wood where the screw went in. His went in from the top. The oak floor was then refinished and you had to look to notice the screw holes.

[Tom M King]

Tom,

I understand I would use 1.25 inch screws with your method? Assuming 3/4" sub floor and 3/4" flooring?

i see the advantage of going up from below when wanting to keep the existing hardwood flooring, but also see how this could be an advantage even if installing a floating floor on top of the existing hardwood... With the exception of not having the solid connection to the floor joists that screws from above would offer.

Thanks is for your help!

Bill

Yes. I used inch and a quarter Deckmates from Home Depot.

[Terry Therneau]

Be careful about going in from the top. You want to pull the subfloor down tight to the joist. A screw which has threads all the way to its head won't do that because it won't "spin" in the top boards when the screw pulls into the joist. This is why deck screws finish with a plain portion of shank, the unthreaded portion is the thickness of the decking. If you could find screws whose unthreaded portion was equal to subfloor + oak you would be golden: snap a chalkline on the floor and aim to get 2 screws in per diagonal board. I did this for my squeaky living room when the carpet was up; that had only a layer of 1/4 ply over the diagonals though so screws were easy to find.

An alternative from below is to use the Kreg mini jig (R3, Junior, ... they keep renaming it). Google "kreg jig squeaky floor" and you will get several hits.

[Bruce Wrenn]

Another job for "Pocket Screw Man!" Because floor is open from bottom, have someone walk on floor above to locate where the squeak actually is. Then while they are standing on offending board, pocket screw it from the bottom. A couple of Kreg's portable jigs can be screwed to side of joist for drilling pocket holes, FYI.

[Michael Weber]

One of my kids used special screws for this purpose that had a head that you broke off after driving the screw, which left a smaller mark in the wood where the screw went in. His went in from the top. The oak floor was then refinished and you had to look to notice the screw holes.
Saw Norm use those on "Ask This Old House" a few years back. Homeowner seemed satisfied