The maximum deflection of a fully loaded residential floor allowed by most modern building codes is L/360. In this formula, L is the span of the joists and 360 is a factor that's been determined to result in the maximum acceptable deflection. For example, if floor joists span 14 ft., or 168 in., the most that floor would be allowed to deflect when fully loaded would be 15/32 in. (168 in./360 = 16/32 in.). Building codes establish minimum standards, not best...
Hardwood flooring in San Jose is classified by grade, species, and type. The grade generally describes the surface characteristics of the wood, lengths of the flooring, and milling tolerances. There are several grading systems for hardwood flooring. Various associations create these systems, and use of the systems by manufacturers is voluntary, so caveat emptor. Two of the more common systems are those created by the maple flooring manufacturers Association (MFMA, maplefloor.org) and the National Wood flooring Association® (NWFA,
Although it is common to install wider boards much like strip flooring, they are more sensitive to changes in moisture content because their greater width allows for more dimensional change per board. Consequently, you need to take some extra measures to ensure a durable installation. Before nailing down the first wide plank board, make sure the flooring has been acclimated within 2% of the sub-floor moisture content. Pay special attention to plainsawn planks, as they are more susceptible to cupping than...
Whether you opt for manual or pneumatic, either kind is less work than fastening flooring by hand, and either kind is available to rent. Although some old-timers claim they installed more by hand than we do today with all our new electric saws and nailing guns, for most of us a flooring nailer is the way to go. Whether manual (bottom) or pneumatic (top), both kinds of nailer beat doing it by hand—and either kind is available to rent. As 15-gauge finish...
Today most craftspeople install wood flooring with flooring nailers—either manual or pneumatic models. Flooring nailers drive the fastener at the correct angle through the flooring and into the subflooring. The nose of the nailer hooks on the top inside corner of the board's tongue, and striking the pad on top of the nailer with the rubber face of a flooring mallet drives the fastener home. Some craftspeople prefer manual flooring nailers to pneumatic ones. Manual nailers have fewer parts to break...
Blind-nailing means the nails go unseen in the finished job. With flooring, this happens by nailing at an angle through the tongue so the head of the nail ends up well below the floor surface. Face-nailing is just that—you nail through the top face of the flooring and putty the hole before finishing. After installing the first row, it's more efficient to set out all the flooring before continuing to install, rather than selecting a board and nailing it down, selecting...
Engineered floors behave somewhat differently than solid wood flooring. Although engineered wood flooring changes less dimensionally than solid wood flooring, engineered floors are notorious for developing gaps between the butt ends of boards. This is because most engineered wood flooring expands the same amount in all directions. The lengths of the boards are many times their width, which magnifies any dimensional change along the length. For this reason, it's important to leave the same amount of expansion clearance around the...
How much clearance should be left between the wall and flooring generally coincides with the thickness of the flooring material. Typically, 3/4 in. of lateral movement is enough to pull the fasteners from the subfloor, so the National Wood Flooring Association (NWFA), the Wood Flooring Manufacturers Association (WFMA), and most manufacturers require a 3/4-in. expansion gap left in all vertical obstructions when installing 3/4-in.-thick solid wood flooring. This is a safe and simple rule across the grain, though it is...
Solid wood flooring will expand or contract with any changes in its moisture content. The main issue isn't, as people tend to think, the floor pushing on the wall and buckling upward. That's primarily an aesthetic problem and, in fact, upward buckling is a sort of relief mechanism. The real concern is that if a floor gets wet and expands, it can exert sufficient pressure to move walls outward and create a structural problem. To address this concern, leave clearance between...
As well as being stiff, subfloors must be reasonably flat or areas of the wood floor would not consistently contact the subfloor, causing squeaks if fasteners don't suck the flooring down tight or adhesives aren't able to bridge the gaps. For wood flooring that requires fasteners l/^ in. or longer, the subfloor must be flat within 3/i6 in. over 6 ft. This is approximately the thickness of two quarters and a penny together. Wood flooring installed using shorter fasteners or...
Before installing (or even bringing) the wood flooring into the room, I inspect the subfloor to be certain it's up to par. With board subflooring, check to be sure the board ends are fully supported on joists and are fastened with at least two 8d ring-shank or rosin-coated nails per joist. If it's an old floor and the nails are loose, add more so the boards don't move. At the ends, the boards might need to be predrilled so new...
Structural wood panels such as plywood and oriented strand board (OSB) are the most common sub-floor materials today. Plywood is composed of thin sheets of veneer, or plies, laid up in cross-laminated layers to form a panel. Cross-lamination minimizes dimensional changes, making an extremely stable product. Plywood always has an odd number of layers, with the face layers' grain usually oriented parallel to the long dimension of the panel. Plywood is stronger along its length than its width so should always...
It's common to think of the stiffness of a floor as being simply a function of the joists, but the joists work in concert with the subfloor. The subfloor helps to distribute point loads between multiple joists, and it stabilizes the joists so they don't roll under load. And whereas joists provide strength and stiffness along their length, the subfloor provides these qualities between the joists. There are three main types of acceptable wood subflooring material: plywood, OSB, and solid boards....
All wood floors have one thing in common: they are only as good as the subfloor beneath them. There are gaps between the boards, and the floors always squeak when you walk on them. The reason? The builder installed the wood flooring over a subfloor consisting of one layer of V2-in. plywood. This subfloor isn't thick enough to hold the flooring nails, so the wood flooring moves constantly. This story is typical. Many flooring problems have more to do with what's...
One in 10 Americans has a hearing loss severe enough to affect their ability to understand speech. It's more common among wood flooring contractors. Nearly everyone I know in this trade has hearing loss, which has made me all the more adamant about hearing protection. Noise is measured in decibels, or dB. The dB scale is logarithmic rather than linear. An increase of 10dB isn't additive; it represents a tenfold increase in noise. Consequently, even a small increase in dB can...
Installing wood floors requires an incredible amount of cutting and nailing, but the most important equipment I own doesn't cut or fasten anything. Nothing comes before safety equipment. With all the cutting, nailing, and chemicals flooring installers work with, it is only a matter of time before an injury will occur if you don't have the proper protection. Many old-time wood flooring contractors are partially deaf because they didn't protect their hearing when using nailers and power tools. Before I started wearing...
You need to be careful when removing old resilient flooring. Many linoleum and vinyl floors from the 1970s and earlier contained asbestos in their backings or adhesives. Various federal, state, and local government agencies have regulations that require special licensed abatement contractors to remove material containing asbestos. (You can find these contractors online or in the Yellow Pages.) I never remove old resilient flooring without having it tested for asbestos first. it is just not worth possible health problems, breaking...
If you're installing a hardwood floor in new construction, all you have to worry about is the condition of the subfloor. But if you're working on a remodel project, you'll likely have to remove an existing floor covering, which might be carpet, linoleum, or vinyl. Removing old floor coverings is my least favorite part of installing wood flooring. REMOVING CARPET No matter how many times a carpet is cleaned throughout its life, removing all the animal dander, dirt, and dead bugs is...
COLOR Wood flooring is available in a variety of colors that can change the feel of any room, making color one of the most critical aesthetic design elements. The palette of colors seems limitless. American walnut provides deep rich brown tones, hard maple has white with tan hues, and purpleheart really is purple. You can stain wood floors, but with the availability of so many colors, I generally try not to—when a stained floor is scratched, it can be hard to...
Even Drying Promotes Straight, Flat Flooring. Because wood dries and shrinks first at the outside, the outer surfaces tend to be in tension while the inside is in compression. Keeping these forces balanced is crucial to keeping the wood flat and straight. That's why even airflow is so important during acclimation. One edge drying faster than the other can result in crooked wood, because that edge exerts more tension on the board. Similarly, one face drying faster than another can cup...
