How To Repair Beading On New Wooden Flooring

What causes beading on my new wood flooring and how can I fix it?

Perma's Fast Answer

1.  Stay off the floor and let the beads harden
2.  Remove beads with a putty knife or scraper
3.  Screen the floor smooth and apply another coat of finish

Don’t Panic!
The Beads Will Harden And Can Be Easily Removed

Don’t worry – beading is a common issue in a new wood floor installation and does not indicate a problem with the wood finish. It is simply extra floor finish that is being pushed to the surface to be removed. The normal procedure is to allow the finish to rise, stay off the floor, and let the finish beads harden. Once they’re hardened and cured, remove them with a putty knife or other scraper, screen the floor smooth and apply another coat of finish.

What is Beading?

Beading is floor coating that settled between floorboards that has been pushed up, due to the natural expansion of the wood during times of higher humidity. The finish is pushed up in beads, hence the term beading. It is often tacky as it has not cured.

What Causes Beading?

Installing a new wood floor is a balancing act. Wood flooring contracts and expands with changes in humidity and temperature. The balancing act involves determining the moisture content of the wood, calculating the humidity range at the installation site, and then allowing sufficient contraction or expansion room between the planking.

For example, if humidity is low at the time of installation, additional space may need to be left between planks to allow for expansion in case the humidity increases – which can happen during the spring and summer months.

When wood finishes are applied to a new floor, it is normal to have some finish flow down between the spaces in the planking. Drag bars and T-bars that are commonly used to apply finishes tend to push the finish between planks.

If the humidity increases and the wooden floor planks expand, the finish is pushed upwards to the surface in beads.

Getting Technical

Polyurethanes form a film through a combination of evaporation of the carrier material, generally mineral spirits in solvent-based systems or water in water-based materials. As the carrier evaporates it initiates cross-linking or film formation of the coating. As the finish dries at the surface, it can trap the carrier in the material that has flowed between the planks, causing it to stay in a semi-liquid or gelled state for an extended period of time. The carrier will usually continue to evaporate out very slowly, but it often takes months before it reaches a solid state.

Note that this doesn’t indicate a problem with the wood finish; it is simply the nature of the way they behave. As the humidity and temperature increase, the planking expands and like a tube of toothpaste, the finish is compressed and squeezed from between the boards, often in the form of little beads. Because it hasn’t cured, it comes out tacky and will pick up dirt and soil causing black lines to appear between the planks or it can adhere to footwear and be tracked throughout a facility.

Unfortunately, wood finishes often continue to be forced up between the planking as the humidity increases, until the wood reaches its maximum level of expansion. However it will settle once the excess has risen, and you can enjoy your beautiful wood flooring.

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