NWFA Tip Sheet: Wood Flooring Replacement
February 3, 2011
Wood flooring replacement assumes that a wood floor is already in place and there is some issue that initiates the option for replacement.
What are some of the situations that begin the replacement discussion?
• The consumer is not pleased with the look and wants a different floor.
• The flooring is too thin for another sanding.
• The flooring has buckled.
• The flooring is loose and creaks and squeaks.
• Extensive pet stains.
The consumer is not pleased with the look of the floor.If the flooring is new, replacement can be pretty straightforward if the wrong flooring was installed. As contractors we have to admit the mistake and replace the flooring with the correct floor. As an aside, we may try to negotiate acceptance of the original floor, but ultimately we are responsible for providing what the consumer ordered. The other straightforward situation is if the customer wants a completely new floor of a different species or size or construction. Give the customer what they want. Some of the points to consider in this situation are to determine; if the chosen product can perform as intended and if the existing flooring product should be removed before replacement installation. For specialty products such as parquets and engineered wood, always check with the manufacturer for their recommendations for installing over an existing floor. For an existing solid wood floor that is sound, has no performance issues, and a height change is not an issue; a simple change of direction with the new flooring and or plywood overlay can create a proper subfloor for the new installation. With a plywood overlay, install it on an angle to prevent gaping related to edge joints and fasten it well to the existing floor, generally on a 6-inch to 8-inch grid pattern.
In the same category is a new floor with a performance problem. For instance, if there are mis-graded boards or a significant number of defective boards in the new floor; how many boards need replacement is the determining factor. If the replacement number is less than 5% of all the boards then it is likely cost effective to replace the individual boards. In my experience and after asking other professionals, if the number of boards is more than 7% then an entire replacement is the most cost effective procedure. Between 5% and 7% is an individual call based on the particular situation. The tricky part is setting proper customer expectations to assure the customer the replacement will not be noticeable. For a site finished floor, refinishing is also part of the process to blend all the replacements, particularly if the age of the flooring has allowed a color change. For a factory finished floor, the color change will have to be discussed with the consumer, advising that over time the new boards will change to blend with the original boards.
The flooring is too thin.The flooring is to be refinished and during the sanding process the nail heads are exposed by the sander, or the top lip of the groove edge breaks or splinters excessively. Sometimes with an old floor nailed with oval headed casing nails they can be set successfully below the sanded surface and refinishing can be completed. Since the nails have a large oval head they may be exposed before the groove edge of the flooring becomes too thin and begins to break or splinter. A 3/4” thick solid wood flooring product should last the life time of the structure with proper care, even when sanded and refinished 3, 4, even 5 or 6 times. However, during this life time a significant water event may occur and the flooring is over sanded as a repair. Also, a non-professional may have sanded the floor excessively. In any case the thickness of the top lip of the groove edge is the determining factor for too-thin flooring. For oak flooring, when the groove lip reaches about 1/8” thick (8/64”) it becomes fragile and begins to break. At this thickness the flooring is likely to be loose and movement and flexing along the groove edge will help cause the breakage. If the groove lip breaks the flooring should be removed and replaced. Groove lip breakage allows too much movement so the existing floor is not a good candidate for sound subflooring.
The flooring has buckled.The definition of a buckled floor is when the flooring expands excessively and typically raises to a peak. In these buckled areas, the flooring is no longer properly attached to the subflooring. This is different from a cupped floor, which has the long edges of boards raised more than the center of the flooring boards. Also, if excessive moisture is the cause of the cupped flooring the eventual result may be a buckled floor. Since a buckled floor is no longer attached, replacement is the only way to properly reattach the flooring. As previous articles have mentioned, the source of the excessive moisture problems must be found and remedied. Then the existing moisture must be dried to a normal condition before the new flooring is installed.
It is possible to salvage buckled flooring if the water was promptly removed and the flooring was not excessively damaged with broken tongues or grooves or does not have excessive staining and mold growth. Most surface staining can be sanded out. If salvage is attempted, the flooring should be sanded perpendicular to the installed direction to scratch the finish to allow better drying. Sanding across the flooring allows the sander to not remove the cupped edges and create a crowning potential. The easiest way to remove nailed solid wood flooring with minimal damage is to cut a run of flooring along the wall that was last installed, the tongue side wall. With a tongue edge exposed use curved claw hammers, not straight clawed ripping hammers, to slide under the nailed tongue edge and pry the flooring up. A hammer in each hand does the trick and goes surprisingly fast with minimal additional damage to the flooring. I have removed severely wetted flooring with a 15% to 20% damage rate. Clip off or drive the nails back out and stack in layers in alternating directions to allow drying. After drying, reinstallation can proceed. If you have to mix new and old flooring the best way is to use complete runs of old or new flooring and randomly mix them to create an overall blended look. As always it is critical to use a moisture meter all through the process to make sure proper drying has occurred.
The flooring is loose and creaks and squeaks.As we reported in the article on refinishing, an old floor can be face nailed or screwed from below to fix these conditions without requiring replacement. Customer expectations are critical since a completely quiet floor is not possible in this case. First it is necessary to determine the cause of the noise. The cause can be any of the connections within the flooring. If it is the subfloor attachment to joist or from too wide joist spacing, or over span, replacing the flooring won’t solve the problem. New joists or supports should be installed and or the subflooring refastened before new flooring replacement. If the cause is the fastener holding ability of the subflooring, such as particle board, removing the particle board is required. If the fastener problem is related to a wetted or low fastener holding of OSB panels, reinstalling new flooring by nailing and gluing has proved adequate to stop the problem. Either a full trowel adhesive application or a squiggle bead along the tongue edge has proven sufficient to reduce the noise to an acceptable level. If the flooring configuration or loose match, flooring tongue and groove fit, is the problem; be sure to reinstall with a properly fitting floor. Gluing and nailing flooring with a loose match can also remedy the problem. In this case the full trowel application is the best but a squiggle of adhesive along the groove edge will most often be sufficient. Remember, any subsequent repair or replacement of a floor that has been glued will result in significant damage to the subfloor.
Excessive pet stains.Most often excessive pet stains are discovered when removing wall-to-wall carpet with the intention of refinishing the flooring. Pet stains of this kind have affected the flooring for a long period of time and are not just surface stains but affect the flooring through the thickness. The only way to get rid of the blackened area is to replace the flooring that is affected. Most of the time the affected flooring is along a wall line away from the traffic areas. Where the affected runs cross the room parallel to the direction of the flooring, removing the runs wall to wall is rather straightforward. If the direction exposes a groove edge, then using a slip tongue and reinstalling is the best option. A more complicated situation is where the stains cross the ends of the flooring. In this case if the affected boards are more than 5% to 7% of the room, replacing the entire floor is the most cost-effective option. If the stains are confined to one area along the end wall, an area replacement can be sufficient. The larger the area to be replaced, the more likely care must be taken to keep the runs oriented so the replacement boards fill the repair with a complete board. When repairing a larger area, use a marker board (a story board) that is marked with the precise distribution of the runs from the old flooring, that is not to be removed. This board is used to position each run as they are replaced. I use a utility knife to mark the location of the runs on the edge of my story board. Then when reinstalling make the board edge along every run fall on the marks. Most often spacing will be required to maintain the board distribution. However, in some cases you may have to use a block plane to shave each board. Of course refinishing the entire room will be required after the replacement repair.
Remember, if more than 7% of flooring boards are affected, complete removal and replacement is the most cost effective option. Where 5% to 7% of boards are affected each situation is different and replacement or repair is an individual call. For 5% or less affected boards, individual replacement is the option of choice. And finally, where the solid wood flooring has less than 1/8” groove lip thickness, it is time for replacement. As always, set proper customer expectations and discuss the options. When repairing, the repair should not be noticeable from the standing position.