What Causes Squeaky Floors?

Unless you are the parent of a teenager, a squeaking hardwood floor is a nuisance. Once a floor starts to voice its opinion about being stepped on, it’s unlikely to stop unless persuaded to do so.

In older homes, the presence of squeaky floors is simply a part of the charm and comes with the territory.

In new construction homes, squeaking hardwood floors can become a frustrating situation with every participant in the construction process blaming another person.

There is however one core cause of a squeaking floor: movement.

It’s pretty rare for a wood floor to squeak on its own. In order for the floor to squeak, it requires some impetus to move and a place to move to.

This is usually the act of being stepped on.

Movement is the cause of squeaks. But that still leaves the million dollar question: what’s allowing the floor to move?

Movement can be caused by a number of factors:

Seasonal Movement

In northern climates, when the outside climate becomes very cold, homes heat the air inside the home. This heating cycle creates very dry conditions inside a home and additional humidification is required to maintain a comfortable humidity in the home.

If the home does become very dry, the wood floors of the home will shrink. This shrinking of the floors will cause tension in the fasteners, causing them to pull.

After the home returns to a normal humidity level, the floors will expand back, but will be more loosely held in the subfloor. This loose hold, combined with friction in the flooring will cause squeaks; either between flooring boards or within the fastener and subfloor.

This process is reversed in homes where the humidity becomes very high, but the stress on the flooring and fasteners is the same, along with the ensuing squeaks.

Subfloor out of level

An out-of-level subfloor has many causes. The essence here is the presence of voids.

To completely avoid squeaks, you must eliminate movement in the wood floor.

If there is a void under the wood floor, of any size, you allow the possibility of movement, which can create a squeak. Eliminate voids; you’ll eliminate movement and squeaks.

Where are the voids in your subfloor?

• Residue on the subfloor. Construction residue on the subfloor (drywall mud, adhesive, unseated fasteners, etc.). Install the flooring over this residue and part of your floor will be suspended in air. Bring on the squeaks!
• High/low areas in the subfloor seams. (Good wood flooring installers will sand the seams of plywood flat). If the subfloor isn’t perfectly flat, parts of the flooring are suspended in air.
• Joists out of level.
• Settling in the home.
• Heaving beams.

Spacing between the subfloor and joists

Just like any void between the wood flooring and the subfloor can allow for movement, any void between the subfloor and the joists can allow for movement.

Realistically, there can be many reasons for voids between subfloor and joists. There’s really only one way to eliminate the chance for voids: to glue and nail the subfloor to joists, and to do it carefully. Unfortunately, this isn’t as common a practice as the flooring professional would like.

Frequently contractors only nail the subfloor down. But nails frequently miss joists and cannot permanently hold and fill the voids where joists don’t meet the subfloor. By gluing and nailing the subfloor, all possible voids between subfloor and joists can be eliminated.

Subfloor seams off center of joists

Hopefully this is an incredibly rare occurrence, but in a rush, a contractor might meet subfloor up off center of the joists. This means that seams of flooring are over a void. When stepped in this area, nothing solid it is resisting the movement of the flooring and subfloor.

Inadequate fastener size or fastener frequency

Very small fasteners will not hold the flooring in the subfloor adequately.

Over time the stress of walking on the floor will cause the small amount of hold of these small or short fasteners to loosen and squeak within the subfloor. This goes the same for inadequate numbers of fasteners.

We’ve put together a video and article that explains the importance of proper fastener use and how to make sure that you’re using the right now. Learn more about it here.

Over seating of fasteners

This is a very common cause of squeaks. When a fastener is over seated into a wood floor, wood material is pushed out of the bottom of the wood floor, raising the overall floor into the air (even ever so slightly).

Wherever there is a void between the flooring and the subfloor, there is possibility for movement, and squeaks.

Poor quality subfloor or degraded subfloor

Subfloors come in varying grades, and experience different elements along the construction stages.

A low-quality subfloor or one that was subjected to rain and/or flooding will be degraded (no matter what the salesman said about it being waterproof). Waterlogged wood chips glued into sheets will not hold fasteners like higher quality plywood that was carefully kept dry.

Too high a quality subfloor

Now this one might get folks riled up.

Is it possible to have too high a quality OSB?

In reality, the use of the word quality was probably not accurate, but I thought it would get your attention.

In some of the OSB’s today, the resin content is so high that the subfloor can be too hard. This makes the product too brittle. Fasteners barely penetrate and once through, the material is too rigid to maintain a hold.

Imagine nailing through sheet metal. The nail might hold for a little while, but once broken loose, the nail’s not just moving, it’s also screaming at you like nails on a chalkboard.

What’s missing from this list?

You may have noticed one particularly commonly held view is absent from this list: “Manufacturer defect.”

This is because manufacturer defect is almost never the cause of simple squeaking in hardwood floors.

Squeaking could be the symptom of a much deeper defect, but the squeak is not the only symptom. The following are commonly held, but mistaken, beliefs about manufactured caused squeaks:

Loose Tongue And Groove

Manufacturers mill the tongue and groove of flooring to fit flooring together and allow for blind nailing of flooring and to ease installation. Manufacturers design the tongue and groove to fit together somewhat snug but allow for enough room to be fit together by hand. This is tested constantly while the flooring is being manufactured.

The important consideration to understand here is that as soon as the moisture content of the flooring changes, the fit of the tongue and groove will change.

If the flooring becomes drier, the tongue and groove will be looser.

If the flooring grows in moisture content, the fit becomes snugger.

The manufacturer cannot guarantee the fit of the tongue and groove in every installation environment.

At the end of the day, it is the responsibility of the installer to ensure that the fit of the tongue and groove is appropriate at the time of installation.

If is squeaking out of the box, then the manufacturer should be contacted.

If it starts squeaking even 24 hours after installation, you can be assured the cause is something other than manufacturing. If it was manufacturer related, it would squeak out of the box.

Delamination

Engineered hardwood flooring rarely delaminates.

The typical cause of flooring separation is extremely dry conditions that tear the flooring apart. But in the case of delamination, squeaks can be a symptom, but the underlying problem is much more severe.

Boards become raised up, curling and no longer stay flat. In this case, the squeaks aren’t usually mentioned because the other issues are too severe.

Conclusion

As you can see, squeaks can be a frustrating puzzle to solve. But once it is understood that movement is the primary cause, and that eliminating movement is the only solution, decisions can be made to remedy the issue.

Experience has taught some possible solutions for squeaks:

• Squeak No More: http://www.oberry-enterprises.com/ this method will allow for top screwing boards, but counter sinking the screws.
• Squeak Ender: http://www.squeakender.com/ this cures the issue of voids between subfloor and flooring joists. Shimming the voids can also help here, but might cause squeaks in other areas.
• Lubricants: This may sound a little hokey, but talcum powder, graphite and WD-40 are all solutions that have helped squeaking floors. This is usually somewhat temporary. One NWFA certified inspector we know swears by WD-40 as a solution. In these cases, the movement is causing friction between the flooring boards. When this is the case, lubricating the friction points will eliminate the sound.
• Screws from underneath to seat the flooring to the subfloor in problem areas.
• Hollow spot repair: drilling a hole in the flooring and filling the void with epoxy is a possible solution:  https://www.woodfloordallas.com

Post used with permission and was originally created by Caleb Unruh with The Master’s Craft Flooring Company. Get more cleaning and care tips at www.themasterscraft.com/resources. See the original post at https://themasterscraft.com/causes-squeaky-floors/.