Floating a Wood Floor

A wood floor may be installed in three methods:

1.) nailed-down, 2.) glued-down, or 3.) floated. A wood floor that has been nailed- or glued-down, has, as the method insinuates, effectively been attached to the subfloor. When installing a wood floor using either of these methods, the primary objective is to ensure the floor never detaches from the subfloor and remains a permanent fixture within the structure.

With floating-floor installations, flooring panels are not aached to the substrate. they are only attached to themselves. the entire area of wood flooring becomes one independent, monolithic unit that has been designed to float freely, without restraint.


The Feeling: Walking across a floating wood floor is different from walking across a nailed-down or glued-down wood floor. For starters, a floating floor is floating. this means that it has the capability of moving below your feet. Not laterally, but vertically. It is common to feel vertical movement, or a spongy feeling when walking across a floating wood floor. Many people specify and prefer living on a floating wood floor due to this “soft” feeling you get from walking across them.

The Sound: The other unique quality of walking across floating wood flooring is the “hollow sound” you may hear as your shoes come into contact with the surface. There is no getting around the fact that a floating floor sounds hollow. Walking across a floating wood floor will sound and feel different from any other type of wood floor installation method.


Regardless of how the engineered floor is constructed and designed for installation, several items need to be addressed and followed during any floating-floor installation. Engineered wood flooring may be floated over most subfloors, as long as it meets the minimum requirements as detailed in the NWFA Installation Guidelines. When available, the flooring manufacturer’s instructions should always be followed. This includes all recommendations and requirements that instruct preparation, installation, or use of the wood floor.


When installing a floating floor, engineered flooring is the only type of wood floor that can be used. Solid wood flooring should never be installed using the floating-floor method unless otherwise recommended and warranted by the flooring manufacturer. In general, solid wood is not dimensionally stable enough, when exposed to seasonal changes, to withstand this installation method. Solid flooring includes solid strand woven flooring products.

Engineered wood floors that are intended to be floated, are attached through either an edge-glued tongue-and-groove construction, or through edges with a locking mechanism.

Edge-glued floating-floors

Apply the specified glue as recommended by the flooring manufacturer. Amount, placement, and type of glue will vary from one wood flooring product to another. Poly vinyl acetate (PVA) glue generally is recommended for floating-floor installations. Glue takes time to dry and will require additional time before foot traffic is allowed. Strapping the boards will help to avoid the installed flooring coming out of alignment before the glue completely dries. The tongue and groove must be engaged snugly. Use of tapping blocks, straps, or a scrap piece of flooring may be necessary to get the flooring tight. Do not damage the edge, butt-end, tongue, or the groove while tapping the product into place.

Clean any excess glue from the surface of the planks as necessary. Some suggest leaving any excess glue beads that have pushed up from the seams to completely dry, and then remove them much easier the following day. This method helps avoid smearing glue across the surface of the plank.

Locking mechanism floating-floors

There are three basic types of locking systems referred to by how the boards are attached to each other, along the length of the plank and at the ends of the plank:
Angle/angle-locking systems: The plank must be angled upward to engage the locking mechanism along the length of the plank as well as the ends of the plank before lowering it to complete the connection. This must happen at the ends first (normally along the entire row), then along the length of the planks.
Angle/hook-locking systems: The plank must be angled upward to engage the locking mechanism along the length of the plank, but the ends of each plank have a hook-lock connection. e ends are not locked in until the next row has been installed.
Angle/fold down-locking systems: Also called “single-action locking” as it locks the floor in one single motion often with an audible click sound. The plank must be angled upward to engage the locking mechanism along the length of the plank, but the ends are equipped with a mechanical locking function that locks the ends in place. Ensure you lock the lengths and the ends of the flooring together correctly as per manufacturer recommendation of the particular locking mechanism being used.


One of the most critical aspects of floating a wood floor is maintaining adequate expansion space at all vertical obstructions to allow for movement within the flooring unit. Unless otherwise directed by the flooring manufacturer, expansion space left between the flooring and vertical obstructions is generally equal to the thickness of the material being installed.

Transition pieces (t-moulding, overlap reducers, thresholds, etc.) allowing for expansion space must be installed to allow the flooring system to remain floating. These transitions should be built into the floating-floor system at any doorways less than four feet in width, and within any flooring system that spans greater than 20 feet in width or greater than 40 feet in length (in comparison to flooring installation direction), unless otherwise directed by the flooring manufacturer.

Baseboard, base shoe, quarter round, and other trim pieces also must allow the flooring system to remain floating. They should not come into contact with the wood floor, allowing it to remain floating. Door jams and trim pieces should be cut and held off of the floor about 1/16” and should never be fastened to or through the flooring system.

Floating-floors should never be installed where future fixed cabinetry (such as kitchen islands) will lock the floor in place, as these are considered “fixed vertical obstructions.” Additionally, any heavy furniture or appliances such as pianos, pool tables, entertainment centers, or refrigerators can affect the ability of the floor to remain free-floating. The flooring manufacturer should provide specific point-load requirements for the flooring being installed, so that you can adequately align the flooring selection with the space requirements. These pieces of information can help you advise the end-user of this condition prior to the product selection or installation.


There are many underlayment systems available for floating-floor installation methods when specifying the project.

Acoustical underlayment materials may include cork, recycled rubber or cork/rubber blends, foam pads, recycled cellulose fiber materials, and dimpled or peel-and-stick membranes. these materials may be attached to the flooring itself, floated over the subfloor, or adhered to the subfloor. Follow the underlayment manufacturer’s instructions for the proper application and installation of any underlayment material being used on the project.

Underlayments can impact wood flooring performance. When installing a floating floor, the underlayment material functions may provide sound control and/or moisture control. Check with the flooring manufacturer or Homeowner Association’s Covenants, Conditions, and Restrictions (CC&Rs), for specific underlayment requirements.

Over concrete substrates, when the acoustical underlayment material does not include a vapor retarder, installation of a separate Class I vapor retarder underneath the acoustical underlayment is often necessary. Over wood substrates above unconditioned spaces, when the acoustical underlayment material does not include a vapor retarder, installation of a separate Class II vapor retarder underneath the acoustical underlayment may be necessary.

Any underlayment materials used below a floated wood floor should have a published compression resistance that meets all minimum requirements of the flooring being installed over it. It is important to check with the flooring manufacturer for minimum compression resistance requirements.

For sound control underlayments, determine the Impact Insulation Class, Delta IIC, or Sound Transmission Class requirements, and then work with the builder, architect, and specifier to identify a flooring and underlayment combination that aligns with the facility requirements. The acoustical underlayment should have a published Delta IIC rating. The Delta IIC rating provides the flooring product’s contribution to the entire assembly in terms of isolating impact footfall noise. The Delta IIC rating can be used to compare the performance of different underlayment materials.

Pressure-sensitive peel-and-stick underlayments may include one-sided peel-and-stick underlayments with the sticky-side faced down, which are used as an acoustical underlayment or moisture retarding membrane. One sided peel-andstick underlayments with the sticky-side faced up are used as a method to mechanically adhere the flooring to the underlayment material and must be installed per flooring and underlayment manufacturer instruction.

Regardless of the flooring system or the underlayment requirements you are using on a floating floor installation, you will need to ensure all manufacturer instructions are closely followed from the jobsite conditions to maintenance requirements. A floating wood floor can be a great installation method in many scenarios. How you sell the unique qualities of living on a floated wood floor, how it is put to use, and how it is installed, will affect the longevity of how it performs. A properly installed and maintained floating wood floor should provide many years of enjoyment for the occupants.

4 thoughts

  1. Many thanks for doing this article Brent, floating floors are definitely gaining momentum in the USA and hopefully one day we can do a Tech Tuesday on the subject. I’d love that…

  2. Thank you very much for the excellent article Mr. Miller, it was very instructive to read it.
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    for more info please visit http://www.arbiton.com
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  3. Thank you for your excellent article. I would like to install a Kahrs floating engineered wood floor in a freestanding office/workshop space that is 12×24′ and will be climate controlled most of the time. There will be one cabinet filled with supplies that weighs about 1500 lbs and a small printing machine that weighs about 350 lbs. Would these equate to the “kitchen island” example you mention above? There will also be a sofa and other smaller cabinets placed in the room. Is a floating floor a bad idea for this space or are there any suggestions you might have to combat these heavy items? Would a traditional 3/4″ hardwood floor nailed to the subfloor (1/5″ plywood) be a better choice or might that result in cupping and gaps due to relative humidity fluctuations? We are in central New York if that helps. Thank you!

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