Most Popular Questions
First, there is no standard for determining if a crack of a particular size is not acceptable or excessive. Cracks are considered "normal cracks" if they close during the humid season of the year. If the cracks close, the natural wood product is simply absorbing the environmental moisture available, expanding, and filling the gap. To prevent unsightly normal cracks, the environment must be modified to minimize the difference between the "Humid" and "Dry" seasons. De-humidification above and below the flooring in the summer may be necessary, conversely, humidification during winter heating may also be required. Permanent cracks may be filled with an appropriate filler and/or by recoating the flooring. This should generally be done during the Spring or Fall when conditions are not extreme and more average. For much of the USA, October and April are the preferred months for remedial action.
1) The most common cause for cupping is excess moisture, which originates from the subfloor, crawl space, basement, and/or slab. Excessive moisture is usually indicated when the average moisture content of the underfloor materials (checked in several places) is more than 4% higher than the average expected EMC (equilibrium moisture content) for the area. (Ref. Behavior of Flooring and Cupping & Crowning*) If excessive moisture is the cause, identify the source, remedy the problem, then allow the flooring to re-acclimate to the new drier environment (this may take a heating season). After drying to normal conditions, the flooring should flatten. If the floor flattens with no significant cracks, movement between pieces, or noises (crackles and squeaks) no further action may be required. Along with the drying, shrinkage cracks, movement, and/or noises may result. For new floors with prominent cracks, movement, and/or noises throughout; re-installation and/or replacement may be indicated. For a floor with the occasionally occurring larger crack (up to 3/32") , with occasional movement and/or noise, with smaller shrinkage cracks (less than 1/32") and little or no additional movement or noises; a good choice for repair is to:1) re-fasten the flooring in those areas which exhibit movement and noises; 2) properly fill the cracks (fill from tongue level to surface, filler should not simply bridge the crack); and 3) re-coat or re-finish. 2) Cupping can also be caused by the flooring acclimating to the area or space environment which has a higher EMC than the average moisture content at installation. This cupping is generally permanent and changes little with the seasons. For permanent cupping (cupping that has not changed noticeably in 12 + months) sanding the floor flat is the most common option, followed by refinishing. In order to maintain the "before refinishing" environment the same type of finish materials and number of coats should be used. After finishing, the floor should remain flat as long as the environment does not change from the previous norm. For the permanently cupped floor which shows a small difference in the cupping with the seasons (i.e. cups more during the humid season) sanding at mid season (spring, fall) mediates the expected change. 3) For minor cupping (cupping which is not prominent and generally only noticeable in reflected light from large windows etc) where traffic wear has not worn the finish on the slightly raised edge, you may have to accept the condition. Over time, 2-4 years, the cupping will probably subside.
The cause(s) of these conditions may be singular or multiple and include one or more of the following. Noises and/or movement may result from: Subfloor to support (joist) connections: i.e.; nail movement in plywood; glue set before plywood installation; laterally moving plywood across glue bead, etc. Flooring to subfloor connections: i.e.; lack of nailing; lack of adequate nailing near ends; improper fasteners such as small wire nails; where staples are used- over driven staples, and broken tongues; etc. Flooring match or tongue and groove fit: i.e., tongue too small for groove or tongue too big for groove, etc. Moisture change: i.e., too much moisture which loosens fasteners, excessive drying which disengages flooring, system stress as moisture tightens a floor, etc. System specification: i.e., inadequate subfloor materials, excessive spans or spacing, etc. Again, any one or all of the above may contribute to a performance problem. Remedies for floors which show movement and/or are noisy: First, if an area of multiple strips move together in unison, a system problem may be the indicated cause. This may require brackets to pull the subfloor to joist from below, and/or face nailing or screwing into joists from above. Second, If singular strips move, a nailing/fastening or match problem may be the indicated cause. When this condition occurs over an entire floor, if accessible, screwing from below with drywall screws with washers to back the head may correct the problem. If the underfloor is not accessible, general face nailing, specifically into joists may correct the problem. As a last resort replacement may be required. For single strip movement in smaller specific areas (not over the entire floor), screwing from below and/or face nailing the indicated areas, most always remedies the movement and noise. Third, if an excessive or high moisture condition has occurred or is present, the cause(s) must be identified and remedied. The flooring should then be allowed to re-acclimate to the new conditions before other remedial repair is initiated.
We have all heard the horror stories about what the sun’s ultraviolet rays can do to our skin. What you may not know is that they can damage hardwood floors and their coatings as well. Hardwood floor are coated for one reason above all others- protection. Coatings help protect wood floors from many elements. Moisture and abrasion are perhaps the most widely discussed, but even sunlight through windows can damage a floor. Ultraviolet rays from sunlight can significantly age wood, much as it does human skin. The more exposure, the more harmful its effects can be. Most coatings help protect the wood from this kind of damage, but ultraviolet light can also cause some obvious and often unwanted changes to the coatings themselves. These changes can alert the look of a wood floor, affecting the appearance of an entire room. Hardwood floors look their best immediately after finishing. Many customers, however, have unrealistic expectations and think the floor will continue to look this way for years to come. In reality, floors yellow considerably over time. If the floor is stained, it may experience significant discoloration. A floor that was once rosewood in color could easily fade to golden brown, given enough time. Whether it’s a commercial or residential job, wood flooring is a significant investment for the customer. Street Shoe Commercial Floor Finish is ideal for a variety of commercial and high- end residential applications, and keeps hardwood flooring as close to that “just finished look” as possible. Street Shoe not only provides greater durability, but it also contains a special U.V stabilizer to minimize yellowing caused by ultraviolet light. It also protects stained floors from losing their original color. After 500 hours in a Q.U.V accelerated weathering tester- standard equipment for this type of test- Street Shoe significantly outperformed all other products tested. For example, when coated over stain, Street Shoe experienced a mere 15% color change while a competitive brand lost 85% of its original color.
Good question. Better question: How many of you have a moisture meter and use it? It is quite common for the installer to check the subfloor and flooring moisture prior to installation, but not as common for people sanding the floor to check the MC. Sanding and finishing should occur when the floor has been acclimated to the proper MC for normal living conditions (temperature and humidity) for that area. It is good practice to record the MC of the floor prior to sanding so you can compare it to the installation MC. It's also important to do this when using waterborne finish because it gives you a baseline value of the MC prior to applying finish; you can tell the finish is dry when the MC reading is at the original reading. Also, it's good insurance to record the MC at all points in the job. There have been situations were the HVAC malfunctioned after the floor was done and the flooring contractor was blamed for the floor problem related to the MC. If you don't have the MC recorded for that job, you cannot prove you checked it.