|Wood Flooring Q&A
Answers to common plank and strip-flooring questions.
Wood floors go hand-in-hand with old houses.
|Narrow boards create the refined floors of
Mrs. Bell’s bedroom in the 1881 Isaac Bell House in Newport,
Rhode Island, a fitting complement to the sophisticated gridwork
motif behind the rest of the room’s woodwork and finishes.
Photo Courtesy of Bret Morgan
They’re traditional and functional—as well as having finishes
highly valued for their rich historic character and warm beauty. Little
wonder then why the phrase “hardwood floors” is such a
magnet in the real estate market, especially given that the generation
of wall-to-wall carpet houses from the 1960s and ’70s were built
without any finished flooring at all. Enduring as they are, wood floors
bear tremendous amounts of use, abuse, and changes and, after many
decades of service, they often need repairs or replacements. Since
most folks don’t wonder about the specifics of wood-floor construction
and care until it’s time to act, here’s a rundown of the
common issues that surface in the quest to keep up old floors or blend
in new flooring seamlessly.
What’s the history of
The most common kinds of wood flooring in old houses can be divided
into two general categories: wide-plank floors (boards typically
8" and wider) often seen in early buildings, rural areas,
or secondary spaces like bedrooms and kitchens; and strip floors
(narrow boards typically 2" to 4" wide), at first
reserved for better rooms but nearly ubiquitous in most houses by
the 20th century. Wide-board floors are the oldest and simplest
type. In most areas they were originally constructed of softwoods
like pine that were durable but easy to hand-saw, then face-nailed
to supporting beams or joists.
True strip floors are a product of the Industrial Revolution, and
started to become widely affordable and reliable in quality in the
1880s. Steam-powered machinery, which made the milling of dense
hardwoods like oak and maple practical, also enabled edge-matching
the sides of each board into a sophisticated system of tongue-and-groove
joints. This system not only integrates hundreds of small boards
into a wood “skin” that shares loads among many boards,
but it also makes possible blind-nailing where nail heads are recessed
below the surface for better appearance and durability.
The woods used for flooring have always depended upon what species
were available and affordable locally, as well as what was attractive
or fashionable. Though softwoods like pine (of which there are many
kinds) have always been popular for wide-board floors, hard pine
and fir are regularly used as strip flooring, and hardwoods like
ash, elm, and chestnut have also been employed for wide-board floors.
What is quartersawn flooring?
When it comes to spec’ing new flooring for repairs or replacements,
the cut of the wood is as important as the species. Like many other
wood building materials, flooring is commonly either flat-sawn,
or quartersawn. In flat sawing, the simplest method, all boards
are sawn from the log in the same manner, like slicing bacon strips
(see previous page). The more sophisticated cut particularly coveted
for flooring is quarter-sawing. Though sawmills can choose among
several methods of quarter-sawing depending upon their needs, the
basic practice is to first saw the log into equal quarters, then
to reposition each quarter and flat-saw across the quarter. This
method produces boards that are more dimensionally stable with a
more uniform appearance.
What are the cuts on the bottoms ?
Called undercutting or relieving, grooves have been milled into
the undersides of some flooring since at least 1900 to both allow
the flooring to rest more solidly on a subfloor and/or to minimize
the potential for warping. Other nuances of construction that are
important to look for when buying replacement flooring are end-matching
(tongues and grooves on board ends, particularly on random-length
flooring), and the matching dimensions (better quality flooring
of the past had more wood above the tongue than below it to allow
for finish scraping). Note that modern prefinished flooring is often
made with a “micro-bevel” along each side of the top
surface that eliminates the need for finish sanding, but may not
be compatible with traditional strip flooring.
Can I install flooring the day it arrives?
Whether you are repairing an existing floor or laying a new one,
it is critical to have the flooring materials at the same moisture
level as the room before they are installed. This means leaving
the materials stacked with spacers in the room they will occupy
for as long as possible—two weeks at a minimum. Without this
time, there is a real chance the flooring will dry out and shrink
after it is installed, resulting in unsightly gaps between boards,
or pick up moisture and expand, creating the potential for buckling.
Though manufactured flooring is shipped kiln-dried to an industry
standard, this does not mean it cannot pick up additional moisture
later. Storage in an unheated garage or installation in the same
building with fresh plasterwork or poured concrete that is still
drying can have a drastic effect.
How do you patch strip flooring?
While old-house strip floors occasionally suffer isolated damage
from deep burns to animal gouges that require a small, surgical
repair, the more common scenario is an in-fill patch—that
is, adding new flooring to cover the space of a removed wall, say,
or a large duct hole cut in the floor. Here the most unobtrusive
repair involves not only matching the wood and cut of the old flooring
as closely as possible, but also blending the repair into the existing
installation by “fingering in” new boards so they match
the spacing of the rest of the floor as closely as possible. To
do this, you must cut back selected boards at varying positions,
then splice in new boards—all without disturbing the flooring
you want to keep.
Start by thoughtfully planning your repair. Measure the offset of
the joints in your existing floor, then plot out a similar pattern
in the area you need to patch. Do your best to take advantage of
the joints already in your favor so that you minimize the work and
loss of good materials, while making most effective use of your
repair stock (which may be limited if you are recycling flooring).
Typically, you want to have boards no shorter than about 24"
and a minimum cutback of 9" to 12" to maintain the
structural integrity of the tongue-and-groove system.
Next, mark the boards you plan to remove and scribe cut lines at
right angles across the boards where you will make a joint. Bore
a 3/4" hole in each board on the waste side of the line,
positioning it in the center of the board to avoid any flooring
nails. Then, starting from the hole, cross-cut the board with a
saber saw, working tangent to the circle circumference. To avoid
cutting the subfloor underneath, shorten the saber-saw blade by
snapping it with pliers so that its maximum travel just reaches
the bottom of the finished flooring.
Afterwards, working from the hole, saw two kerfs down the center
of the board to cut out a relief strip—wood that once removed
allows you to pry out the groove and tongue sides of the board without
damaging the adjacent flooring. Make these blind cuts with a circular
saw, setting the blade depth to just about the thickness of the
How do you get new boards into the tongues and grooves?
With an in-fill repair, you can often slide some of the new flooring
into place between the existing tongues and grooves. Where this
is not possible, though, you have to “cheat-in” the
new board around the system. One method is to cut off the bottom
groove shoulder of your patch board so you can nose the tongue into
place (usually with a little planing of the bottom corner of the
board), then pop the groove over the existing tongue. To secure
the board, you either face-nail the board with finishing nails (which
are set and filled) or you can glue the board to the cut-off portion
of the shoulder that you have put in place beforehand.
What about strip floors that are basically sound but squeaky?
Squeaks and springy spots in old floors are, strictly speaking,
not normal. Solutions vary with the construction of the floor and
the cause—generally, insufficient contact with the subfloor.
If you can get below the floor, first have someone walk around on
top so you can identify the location and source of problems—often
shrunken or poorly supported subfloor boards. Try adding support
by nailing a cleat (a 1" or 2" stick) alongside a
joist, or driving a wood screw up through the subfloor to secure
a loose floorboard. Where you have no access from below, or the
problem stems from a loose-fitting tongue and groove, try driving
two ribbed finish nails at opposing angles—preferably into
a joist—to secure the floorboards.
After taking the finish off an old floor, can you stain
Yes, but you should know what you’re getting into first. Many
an old-house owner has stained a freshly sanded floor and returned
to find that, contrary to their expectations of a mellow grain pattern,
the floor has become a mess of blotchy patches. This is the result
of uneven stain absorption. What’s the reason? Though most
bare wood takes stain in varying degrees depending upon what part
of the grain structure is exposed—the very effect desired
with stain—a newly sanded old floor presents a different scenario.
Here, some areas of wood are exposed much as they would be newly
milled wood, while others still retain old finish that has deeply
penetrated the surface, effectively sealing the wood pores from
stain penetration. Extreme conditions like sunk-and-filled nails
or spot repairs exacerbate the difference. What’s the solution?
Test the effects of the stain first in a limited, out-of-the-way
area, and if you anticipate any problems, prepare the surface first
with a stain controller—a finishing product that evens the
absorption of the wood.
A Clearer View of Floor Finishes
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