perimeter of the room, along cabinet bases—in
short, any place that would be difficult to edge
with a large applicator. Pour finish into a sloping
flows toward the inside of the room so you can
paint tray with a replaceable liner so you can eas- spread it out on the return pass. The ballet comes
ily reload the paint pad, brush, or large applicator. at the end of each turn, as you sweep the applica-
If you’re applying a slow-drying finish, you
tor pad 180º, spread the finish evenly, and set up
can edge the whole room before switching to a
for the next pass. It’s easier to do than to describe.
large applicator. However, because water-based
Periodically pour more finish in a long puddle
finishes dry quickly, it’s best to edge one section
to maintain a wet edge. Having a second person
of a wall at a time so you can use a T-bar applica-
to pour the finish and touch up missed spots is
tor to overlap edged borders while they’re still wet. helpful but not essential. If you see a missed spot
Maintaining a wet edge is the key when applying
after the finish has started to set, let it dry and be
water-based finishes: Edges that dry before they’re
sure to coat that area the following day, when
overlapped have a distinct lap mark.
you apply the next coat. Once each coat is dry,
screen-sand it lightly, vacuum, and dry-mop it
Working the floor with a T-bar applicator is
with a tack rag over the mop. Then apply the
like a ballet with chemicals. After cutting the
next coat.
edge, pour a thin puddle of finish along one wall,
In general, don’t walk on the floor until the
parallel to the floorboards, but stop the puddle
final coat has cured at least three days, and—
3 ft. to 4 ft. shy of the far wall. Holding the appli-
because this finish is water based—do not damp-
cator pad at a slight angle—somewhat like a
mop it for a month.
snowplow blade—pull the applicator through the
finish. Angle the applicator so that excess finish
Instal ing Strip Flooring
T&G strip flooring, 3⁄4 in. thick and 21⁄4 in. to
31⁄4 in. wide, is by far the most commonly
Fil ing HOlES And GAPS installed wood flooring. Installing it requires
P R O T I P
flooring stores carry color-matched spot fillers
few specialized tools and, with a modest amount
of prep work, it goes down fast and lasts a
and trowel fillers. spot filler is basically wood-
long time.
as you install strip flooring,
worker’s putty, applied with a spackling knife to
use wood from several different
fill nail holes and obvious cracks. trowel filler,
PrEP StEPS
bundles or cartons to ensure a
which is thinner, is poured onto the floor in
varied mix of color and grain. if
small amounts and worked into the narrow gaps
Wood absorbs water and swells, so don’t bring
strips are noticeably lighter or
between floorboards, using a large squeegee or a
hardwood flooring on site until the building is
darker, distribute them through-
closed in and “wet work” (such as plumbing, til-
smooth-edge trowel. done on your knees, apply-
out the floor to avoid obvious,
ing, drywalling, plastering, and painting) are
ing trowel filler is hard work, requiring pressure
odd-color sections. Stagger
complete. Allow paint, plaster, or joint compound
board ends in adjacent rows by
to force the filler into gaps and to scrape off
several days to dry. If necessary, turn on the heat-
at least 6 in. because random
excess. consequently, although spot-filling is
ing or air-conditioning so indoor conditions will
joint patterns will be visually
common, trowel-filling is not. note: if you’ve
less intrusive.
be close to normal (60ºF to 80ºF) for a week
got wide pine planks, which expand and contract
before installing flooring. Open the bundles of
seasonally, don’t fill the gaps between them.
wood flooring and allow them to acclimate
brag about their rustic charm instead.
indoors for 72 hours before installing them.
Flooring
571
Square-edge wood-strip
Use a moisture meter to check interiors if your
flooring is face-nailed, so use a
region has high humidity. Home centers and
straightedge to line up the nails
electronics stores carry reliable, inexpensive
for a neat, professional
meters. Ambient humidity indoors should be
appearance. Because tongue-
35% to 55%; if readings are higher, consider
and-groove flooring is nailed
through the tongues, those
installing a dehumidifier. Also check the moisture
nails are hidden.
content (MC) of wood subfloors and flooring,
using a moisture meter with probes. Typically,
wood flooring’s MC is 6% to 10%. The subfloor’s
MC should not vary more than 4% from that of
the flooring’s.
If you’re installing floors over a basement or
crawlspace, check the humidity of that area, too.
If it’s too high, correct any contributing factors
before installing wood floors; high humidity also
encourages mold. Crawlspaces with dirt floors
should be covered with plastic and sealed to limit
moisture and air infiltration, as described in
chapter 14.
Survey subfloors to make sure they’re solid, flat,
and clean. If floors are excessively springy, stiffen
them by adding blocking between the joists, add-
ing plywood or OSB panels over existing sub-
floors, or sistering new joists to old ones, as
described in chapter 8. In older houses, floors are
Subflooring And UndERlAymEnT rarely level; so if they’re solid, it’s more important
subflooring is usually cdX plywood or osb panels whose long edges run perpendicular
that they be flat—within 1⁄2 in. per 10 ft. Use a
to floor joists—although in older houses, subflooring may be 1-in. boards run diago-
rental edging sander or a woodworker’s belt
nally. to allow for expansion and to minimize squeaks, leave 1⁄8-in. gaps between
sander with coarse sandpaper to lower high
square-edged panels, nailing the panels to joists every 6 in.; ring-shank or spiral nails
spots; use strips of building paper (15-lb. felt
hold best. (t&g panels have integral expansion gaps, so butt their edges tight.)
paper rather than rosin paper) or wood shims to
undersize subflooring often sags between joists, creating high spots over the joists
build up low spots. In general, masonry floor-
leveling compound is too inflexible to use
and floors that are springy and squeaky. adding blocking between the joists may
beneath wood flooring because flooring nails will
stiffen and quiet floors.
fragment it and bo
ard flexion will fracture it.
Underlayment is a layer placed over the subfloor and under the finish floor. there
If you notice protruding nail heads, not
are several types of underlayment. rigid types such as particleboard or hardboard can
enough nails, or squeaky spots, correct these con-
stiffen the subfloor and level out irregularities—especially important when thin
ditions now. Squeaks can usually be silenced by
flooring such as linoleum
screwing down subflooring to joists near the
would telegraph gaps or an
squeak or by nailing it down with ring-shank or
uneven substrate. other
spiral nails. Vacuum and sweep the floor well. If
types of underlayment act
zzzzzz anatomy of a Floor
the floor is over an occasionally damp basement
as a cushioning layer, such
or crawlspace, staple 15-lb. building paper to
as the padding used
the subfloor, overlapping roll seams by 6 in.
beneath carpeting or the
However, don’t bother with building paper if
foam layer specified
the subfloor areas are dry or if the floor is on an
beneath engineered wood
upper story.
flooring. felt paper is
Finally, remove the baseboard molding if you
can do so without damaging it. Baseboards hide
sometimes used as under-
the expansion gap between the perimeter of the
layment in dry, above-grade
flooring and the base of the wall. At the very
applications. underlayment
Finish floor
Joist
least, install a piece of quarter-round shoe mold-
intended for below-grade
ing to cover the gap if you can’t remove the base-
use often combines a vapor
Underlayment
boards. If door casings are already installed,
barrier with some kind of
Plywood subfloor
undercut (trim the bottoms of) each side jamb by
foam cushioning.
the thickness of the flooring; an undercut saw is
specially designed for this task. An oscillating
572 Chapter 20
Floor nailing Schedule*
size and tyPe
flooring
size nail to use
sPacing
t&g strips†
2-in. barbed flooring cleat,‡ 7d or 10 in. to 12 in. apart;
(3⁄4 in. 11⁄2 in.,
8d flooring nail, or 2-in. 15-gauge
8 in. to 10 in. preferred
21⁄4 in., 31⁄4 in.)
staples with 1⁄2-in. crowns‡
t&g† strips
11⁄2-in. barbed flooring cleat
10 in. apart
(1⁄2 in. 11⁄2 in.,
or 5d cut-steel or wire-casing nail
2 in.)
t&g strips
11⁄4-in. barbed flooring cleat
8 in. apart
(3⁄8 in. 11⁄2 in.,
or 4d bright wire casing nail
2 in.)
square-edge strips§ 1-in. 15-gauge barbed
2 nails every 7 in.
(5⁄16 in. 11⁄2 in.,
flooring brad
2 in.)
square-edge strips§ 1-in. 15-gauge barbed
1 nail every 5 in. on
(5⁄16 in. 11⁄3 in.)
flooring brad
alternate sides of strip
Planks
2-in. barbed flooring cleat,‡ 7d or 8 in. apart
(4 in. to 8 in.)
8d flooring nail, or 2-in. 15-gauge
staples with 1⁄2-in. crowns‡
A pneumatic floor nailer will drive nails or staples at the
* Adapted from the NWFA: The National Wood Flooring Association, all rights reserved © 2004.
correct depth all day long, once you’ve calibrated its
† Tongue-and-groove (T&G) flooring is blind-nailed on the tongue edge, with face-nailing
pressure. You don’t need to hit the rubber strike cap hard
required on the starting and finishing runs.
to make the nailer fire.
‡ NOFMA Hardwood Flooring™ must be installed over a proper subfloor.
Use 11⁄2-in. fasteners with a 3⁄4-in. plywood subfloor on a concrete slab.
A concrete slab with sleepers every 12 in. on center does not always require a subfloor.
multitool with a wood blade is even faster.
§ Square-edge flooring is face-nailed.
Remove doorway thresholds if they’re nailed
down. But if they’re glued down or set in mortar,
simply butt the flooring to them.
Pneumatic flooring nailers are more expensive
EquiPMEnt
than manual nailers, but they don’t depend on
your strength to drive flooring nails to the correct
Sawdust or debris trapped under a board can
depth. Nailers aren’t foolproof, though. Take a
mean uneven, loose, or squeaky floors later on,
sample of the flooring to the rental company to
so be obsessive about keeping subfloors clean as
ensure that the pneumatic nailer will correctly
you install flooring.
engage the flooring edge profile. That is, the tool
Installation tools include safety glasses, hearing may need an adapter to avoid damaging the
protection, knee pads, chopsaw or small table-
boards’ tongues. On site at the start of the job,
saw, hammer, nail set, tape measure, chalkline,
calibrate the nailer’s pressure by nailing a “prac-
flat pry bar to remove trim, large flat-bladed
tice row” of flooring to the subfloor. Typically,
screwdriver to draw board edges tight to each
pneumatic nailers are set at 70 psi; adjust the
other, flooring mallet, and a manual or pneumatic pressure up or down until the tool sets nails cor-
flooring nailer. For the little bit of face-nailing to
rectly, as shown in “How Deep Can You Sand?”
be done, use a pneumatic finish nailer; if you
on p. 563. Once the setting is correct, pull up the
haven’t got one, use a 1⁄16-in. bit to predrill holes
practice row.
for the face nails. You’ll need white glue to secure
floorboards under toekicks and in other odd
laYout, StartEr
spaces where it’s difficult to reach with any nailer.
roWS, and BEYond
Finally, rent a shop vacuum if you don’t own one.
And be sure to have a good-quality broom and a
There are two places to install a starter row. The
dustpan.
first and most obvious place is along a long wall.
Flooring
573
The second place is down the center of the room,
which is recommended when rooms are wider
than 15 ft., when rooms are complex, when sev-
zzzzzz Concealing Floorboard Edges
eral rooms converge, and when walls are out of
parallel by 1 in. or more.
Framing
Flooring usually runs parallel to the length of
a room, so start by measuring the width of the
Baseboard
room at several points to see if the walls are par-
allel. If the walls aren’t parallel, split the differ-
Drywall cut 1 in.
&nbs
p; ence eventually by ripping down the final row of
above subfloor
boards on both sides of the room.
Use baseboards to conceal the expansion
Adding a spline, as shown on the left,
Flooring
gaps. If baseboards aren’t thick enough to con-
creates a tongue-and-groove board
ceal the gaps, add molding shoes, or cut back the
with two tongues so you can nail
outward from that board in two
drywall as shown in “Concealing Floorboard
directions. Use a spline when you
Edges” at left.
want to start an installation in the
Installing the starter row along a long wall.
middle of a room.
At both ends of the room, measure out from the
wall the width of a floorboard plus 3⁄4 in. for expan-
sion. Snap a chalkline through those two points
Subfloor
so you’ll have a straight line to align the starter
3/4-in.
row to. Place the groove edges of the first row
expansion gap
toward the wall, so the boards’ tongues face into
the room. If you pick straight boards for the
When walls are out of square, baseboards
starter row, successive rows will be more likely
or shoe molding may not be wide enough to
to stay straight. Face-nail the boards in the starter
cover the 3/4-in. gap wood floors require. In
row, driving pairs of 6d or 8d nails every 10 in.
that case, trim the bottom of the drywall
to 12 in., and placing them in 1 in. from the
about 1 in. to gain additional space.
boards’ edges.
If you use a pneumatic finish nailer to face-
nail the boards, you’ll be unlikely to split them. If
you hand-drive the face nails, use a 1⁄16-in. bit to
predrill for 6d spiral nails. In either case, sink the
nail heads below the surface of the wood, and
eventually fill holes with wood putty. Next, use
the pneumatic flooring nailer to blind-nail (nail
through tongues) boards every 10 in. to 12 in. To
further avoid splits, don’t nail within 2 in. to 3 in.
of a board’s end. Once the starter row is secured,
blind-nail subsequent floorboards until you reach
the opposite wall and run out of room to use the
pneumatic nailer.
Installing the starter row in the middle of the
room. Measure out from both long walls to find
the approximate center of the room. If walls
aren’t parallel, the centerline should split the dif-
ference of the measurements between the two
walls. Snap a chalkline to indicate the centerline;
Renovation 4th Edition Page 132