NWFA Tip Sheet: Remediation of Noisy Wood Floors
The first objective is to determine what is producing the noise. Any connection within the floor system can be a potential candidate. The two main flooring systems are either a wood framed system or the concrete slab.
The wood framed system connections·The supporting joists and their flexibility can produce movement and result in noises. The subflooring to joist connection can be a source of noise where the subflooring is not fastened properly. This can include such items as not enough nails into the joist, the wrong type of nail, and improper or lack of bond from the subfloor adhesive.
·The subflooring itself can contribute to noises. Particle board is well known for fastener movement and resulting squeaks. Some OSB products have shown low fastener retention as well (Photo 1). When coupled with typical moisture events during construction, OSB subflooring is at risk for producing noises related to moisture-induced thickness swell associated with reduced density and irregular flatness. Plywood on the other hand may show some delamination which affects fastener holding.
·The actual flooring fastener can contribute to noises if improperly placed or an incorrect fastener is used. Over driving the fastener has been shown to split the flooring tongue away from the board and compromise the fastener connection (Photos 1 and 2). Smooth shanked brads and other small stick nails don’t hold well and can contribute to noises.
·The flooring itself can contribute to noises where the match (the tongue and groove fit) is improper (Photo 3). Typically the offender is that the groove is too wide for the mating tongue and movement is allowed. Movement can also occur when the match is not properly aligned and one edge is raised above the other. Another source can be when the lower groove lip is too thin for the mating space under the tongue.
The concrete slab connectionsThis system involves either a subfloor system for nailing the flooring or a flooring adhesive application. Where the naildown system is used, the connections into the subfloor are the same as with the framed system as shown above.
·With the nail down system, the sleeper/plywood-to-slab connection can be a noise source. With sleepers or plywood, the fastening system, typically concrete pins/nails may not hold and allow movement (Photo 4). The pins may be improperly driven, not properly seated, and/ or even break the concrete (Photo 5).
·Improperly spread adhesive can compromise the adhesive bond and allow movement.
With all the systems improper components such as: too thin subflooring/sleeper, too wide spacing of sleepers, incorrect subflooring/sleeper species, incorrect adhesive, incorrect fasteners, and others can contribute to noises. Improper site environmental conditions as well as improper flooring moisture content, and resulting movement from too-wet or too-dry conditions, can contribute to noises.
So what about remediation? Remediation can begin by avoiding the improprieties in the first place. Chose the correct system components and properly use them. Check the site conditions and flooring for proper acclimation. Flatten the slab as necessary. Check subfloor for proper fastening. Check the flooring product for the normal fit.
Despite our best efforts noises develop. What are some of the options for repair and remediation?
A single board that produces noisesThis board can be individually replaced and or refastened. If the board depresses too much, replacement is the rule as refastening will likely create a low board. When replacing, make sure the new board finishes out at proper height. This requires dry fitting before final fastening. Use a fast setting epoxy for fastening as this avoids the fastener hole. If refastening is the choice, using #1 square drive trim screws driven into a pilot hole will almost always fix the noise. Chose the proper grain and use a blending color wood filler to cover the screw hole. Remember, the proper repair is not noticeable from a standing position.
A generally noisy floorFor an older floor that is going to be refinished, face nailing can be an option. Most of the time noisy flooring has resulted from years of abuse, gapping, and older fasteners. Cleats are generally the best choice for face nailing as they are serrated and hold well. The aforementioned trim screws can also work though they will take more time and are generally more obvious. Determine where the noise is coming from such as the groove side or at ends. Then pay particular attention to those areas and pick the darker open grain for placing the fastener as they will be easier to hide. Fill the holes and refinish the flooring. I have used as many as a small box of flooring cleats for a 250-square-foot repair of this nature. For this repair set customer expectations by reporting that the noises can be reduced but likely not eliminated.
If the noises are a result of joists to subfloor connection, there are brackets that can refasten and pull the subflooring to the joist. If there is space between the joists and subfloor, shims driven into the space and glued can eliminate the movement. Generally, don’t use tapered wedges as they have a tendency to work out.
Where the noises are determined to be directly associated with flooring movement (Photo 7), whether from improper fastening such as split tongues or a loose match fit, (besides face nailing) screwing from below can be an option for repair. Of course, with this repair you have to have access to the subfloor from below. Screws should extend into the flooring to the plane at the top of the tongue. Screws should be backed by a washer on the subfloor surface and pilot holes make for better draw down onto the subflooring. Using drywall type screws may be counterproductive as they tend to break or not pull the flooring tight to eliminate the noise.
When the noises are general and associated with subflooring performance, match or fastening, another option is to remove and replace the flooring. If the subflooring is a part of the problem and or a loose match is suspect, using a flooring adhesive during installation is suggested. This can eliminate the loose fastener associated with a low strength subfloor material and or the movement associated with a loose match. With the low strength subflooring, a full trowel application of adhesive is suggested. This eliminates relying on the long term fastener performance. With a loose match or where the tongues were broken, installing with proper attention to seating the fastener and using a bead of adhesive along the groove edge will eliminate groove edge movement. In this case the nail/cleat holds the tongue edge and the glue holds the groove edge and is somewhat more cost effective than the full trowel method. Remember, with any subsequent repair or replacement, damaging the subflooring is a likely result.
Noises associated with the slab systemWith an adhesive application where specific areas show movement and noise, the typically cause is from uneven slabs. In this case the glue injection systems offered can effectively eliminate the noises.
Another option is to replace affected areas. Where the general adhesive bond is inadequate this is a likely option. Where too much trash/contaminate or a loose subfloor system was the culprit, the only way to get an adequate bond is to remove the trash (Photo 8) and or refasten the subfloor which obviously requires removing the flooring.
Noisy floors are tough to address and as noted above can be expensive and require extensive time to repair. With any new floor, the best treatment is to eliminate the possibility in the first place. Follow correct procedures and manufacturers’ directions. Be sure site conditions are correct and elevated or excessive moisture will not lead to fastener failure and resulting noises. On the other side, improper acclimation can also be a culprit if the flooring is expected to shrink and result in disengagement of the match. If during installation you notice movement and noises right away, stop and assess the system. Contact the distributor if the problem is not associated with your installation procedures. The distributor can help support you in determining the problem and finding a solution.