Renovation 4th Edition
Page 14
for standard 5⁄8-in. anchor bolts. On the hammer
ally 20 cu. yd. You’ll also pay for the dumping fee
setting, the tool punches as it turns, somewhat
the company must pay to your municipality.
like a jackhammer. Get a model with padded
handles as well as vibration reduction.
tools
57
Building
4 Materials
This chapter offers an overview of the mate-
rials needed to frame and sheath a house. The list
includes standard lumber, engineered lumber,
sheet materials such as plywood and particle-
board, and fasteners, including nails, screws, and
construction adhesives. Finish materials used in
cabinets are discussed in chapter 13, and finish
trim choices can be found in chapter 17.
There’s never been a wider choice of building
materials or more accessible information on
using them, whether you need to size ceiling
joists or find an environmentally safe adhesive.
Just type your requirements into a website calcu-
lator or ask your lumber supplier for a recom-
mendation. Framing techniques are discussed at
length in chapter 8.
Standard Lumber
Wood is a superb building material. It is strong,
economical, and easily worked. In tree or lumber
form, wood can withstand great loads, yet it’s
resilient enough to regain its shape when loads
are removed. Standard lumber is lumber sawn
from logs in the traditional manner; engineered
lumber is often an amalgam of peeled, shredded,
or reassembled wood pieces and strong adhesives.
Lumber grades
After lumber has been milled, each piece is visu-
ally graded according to established performance
standards and then stamped. This grade stamp is
important because building inspectors won’t
approve structures built with unstamped lumber.
Otherwise, they’d have no way of knowing what
loads the wood can support.
Dimension lumber is sawn from logs and milled to a thickness and width slightly less than its
nominal end cross sections. For example, the ends of these 2x6s actually measure 11⁄2 in. by 51⁄2 in.
58
In brief, grading is based on the presence of
ing that when trees arrive at a sawmill, they still
warping, knots, holes, decay, or other imperfec-
contain a lot of moisture. Lumber that’s too wet
tions that could weaken the lumber and reduce
is heavy, difficult to work, and dimensionally
its load-bearing capacity. Generally, dimension
unstable—it will shrink excessively and perhaps
lumber grades are based on strength, appear-
warp as it dries. So after sawmills rough-cut logs,
ance, or both. The more imperfections the wood
they air-dry or kiln-dry (KD) the newly milled
has, the lower the grade.
wood before planing it into finish lumber.
Grade stamps indicate lumber grade, tree spe-
The degree of dryness is expressed as mois-
cies, moisture content when the lumber was sur-
ture content (MC). According to the Western
faced, sawmill, and regional agency certifying the Wood Products Association, “Moisture content is
grading standards. Lumber that is stress-rated by a weight relationship . . . for example, if a piece
machine will have additional information.
of wood has a moisture content of 21%, it weighs
21% more than if all the moisture were removed.”
Structural framing lumber grades run from
Select Structural (the best looking and strongest)
through No. 1, No. 2, and No. 3. An architect
might specify Select Structural 4x8s, for example,
when beams will be exposed in a living room.
In most grading systems, No. 1 and No. 2 are
Select
equally strong, although No. 1 has fewer cosmetic
structural
flaws. Thus, if appearance is not a factor, you can
quality
order “No. 2 and better” without sacrificing
strength. No. 3 is the weakest and least expensive
Certifying
grade in the structural category; you won’t save
agency
much by using it because you’ll have to order
larger dimensions to carry the same loads as
Kiln dried
No. 1 and No. 2 grades.
Light framing lumber,
Mill number
which is used for plates,
sills, and blocking, has lower strength require-
Douglas fir
ments than structural framing members. Light
(northern
framing members are 4 in. (thick or wide) or less.
species)
Grades are Construction (the best), Standard,
Lumber grade stamps.
and Utility. Contractors often order “Standard
and better.”
P R O T I P
Stud lumber is graded Stud or Economy Stud.
Yard TaLk
In general, avoid Economy grade lumber of any
different species have differ-
kind. Although it’s OK for temporary use, its infe-
Here’s some standard lumberyard lingo:
ent densities, elasticity, and
rior quality makes it unreliable in any sustained
BoarDS are less than 2 in. thick and are used
load-bearing capacities, so their
load-bearing situation.
as trim, sheathing, subflooring, battens,
lumber grades are not inter-
doorstops, shelves, and so on.
changeable. For example, a no. 1
Lumber species
Hem-Fir 2x10 may not have the
LuMBer (dimension lumber) is 2 in. to 4 in.
same load/span capacity as a
Species are denoted by abbreviations such as PP
thick and is used for framing: studs, posts,
no. 1 southern pine 2x10. that’s
(ponderosa pine), DF (Douglas fir), and HEM
joists, beams, headers, rafters, stair carriages,
why structural engineers rou-
(hemlock). Often, manufacturers will group spe-
and so on.
tinely specify both the grade and
cies with similar properties. S-P-F (spruce, pine,
FaCtory or SHop LuMBer is wood milled
species of lumber (or species
fir) is by far the most common Canadian group-
into window casings, trim, and other elements.
group) needed to satisfy require-
ing, and HEM-FIR (hemlock, fir) is common
ments in building codes.
throughout the United States. Because lumber is
tiMBer is at least 5 in. thick in its smallest
heavy and expensive to ship, lumberyard sources
dimension.
tend to be from nearby mills. Since your lumber-
StoCK applies to any building material in its
yard is likely to carry only a mixed stock of sizes
unworked form, as it comes from the lumberyard
and grades, your choice may be limited to what’s
or mill.
on hand.
a StiCK is jargon for a piece of lumber, such
moisture content
as a 2x4: “if that stick is too
warped, go get
another.”
A mature, living tree can pump a ton of water
into the atmosphere each day. So it’s not surpris-
building materials
59
Once it has been dried, lumber is graded accord-
ing to its moisture content:
softwoods aren’T aLwayS
S-GRN has MC greater than 19%.
Most construction lumber is called
S-DRY/KD/KD-HT has MC less than 19%.
softwood,
which is the lumber industry’s term for wood
MC-15/KD-15 has MC not greater than 15%.
from conifers, needle-leaved evergreens such as
Kiln-dried lumber tends to cost more because
pine, fir, spruce, and hemlock. For the most part,
kilns use energy; consequently, most builders use
these softwoods are softer and less dense than
air-dried lumber for new construction. After a
most hardwoods, which come from broad-leaved
structure is framed and sheathed, the wood contin-
deciduous trees such as maple, oak, and walnut.
ues to dry anyway. Thus, S-DRY or MC-15 grades
that said, some softwoods, namely southern yel-
are fine for renovation framing, although if you’re
framing interior walls inside a tight building enve-
low pine, are much harder than some hardwoods,
lope, spending a bit extra for KD-15 might be a
such as basswood.
smart move. The lumber in old houses is often very
dry. In any event, avoid S-GRN: Shrinking lumber
can wreak havoc with finish surfaces.
measuring 11⁄2 in. by 31⁄2 in. Still, you pay for the
Lumber sizes
P R O T I P
nominal size.
Lumber’s final size depends on milling processes.
Another way to size wood, especially hard-
never assume that a piece of
In smaller mills, lumber is often sawn, stickered,
wood and Select finished woods, is by 1⁄4-in.
lumber is straight or that its ends
and allowed to air-dry for four to six months. If
increments: 2/4, 3/4, 4/4, 5/4 , 6/4, and so on. The
are square. at the lumberyard,
it’s not milled further, it’s called rough-cut lumber. nominal actual difference is present here, too:
eyeball lumber along its length
Depending on the accuracy of the sawyer, the size For example, a nominal 5/4 stair tread is actually
and refuse badly cupped or
may vary slightly, but the nominal size of, say, a
1 in. thick.
warped stock. then, before mea-
rough-cut 2x4 is usually a full 2 in. by 4 in.
suring and cutting lumber, use a
However, most lumber is rough-cut and then
pressure-treated Lumber
square to check the ends.
surfaced (run through a planer to achieve uni-
Lumber may also be marked as pressure treated.
form thickness) before being kiln-dried. At each
Such wood, after treatment, may be left exposed
stage, the lumber size decreases. When you
to weather, used near the foundation, or other-
order a 2x4 (nominal size), you receive a piece
wise subjected to moisture, insects, or extremes
of climate. If the wood will remain in contact
with the soil, be sure that it is also rated for
Ground Contact. Note, however, that any wood
sitting on the ground, even redwood, will rot
nominal and actual eventually.
sizes of softwood
At one time, roughly 90% of all pressure-
treated lumber was treated with chromated cop-
NoMiNaL
aCtuaL (in.)
per arsenate (CCA). But the U.S. Environmental
12
3⁄411⁄2
Protection Agency (EPA) determined that CCA
leaches arsenic into the soil. As a result, industry
14
3⁄431⁄2
leaders agreed to stop using CCA treatment for
16
3⁄451⁄2
most residential applications by the end of 2003.
More benign types of pressure-treated lumber,
18
3⁄471⁄4
such as alkaline copper quat (0.40 ACQ) and
copper boron azole (CBA) are available. Both
110
3⁄491⁄4
biocides are arsenic-free.
112
3⁄4111⁄4
Whatever lumber treatment you consider,
consult its product data sheets for the relative
24
11⁄231⁄2
safety of the chemicals used and whatever care
26
11⁄251⁄2
you should take when handling, storing, and
cutting it. In fact, it’s smart to capture and safely
28
11⁄271⁄2
dispose of the sawdust.
210
11⁄291⁄2
212
11⁄2111⁄2
60
chapter 4
ordering Lumber and
Salvaged framing materials may not be worth
caLcuLating board Feet
the effort if they are in small quantities or if, after
removing them, you find that they will be too
The price of long, thin pieces of wood, such as
short. For example, by the time you pry 2x4 studs
molding or furring strips, is based on their length, free from plates, remove nails, and cut off split
or lineal feet (lin. ft.). Sheet materials such as ply-
ends, the studs may be only 7 ft. long.
wood and composite board are sold by the square
Some materials just aren’t worth removing.
foot, which is length × width; sheet thickness
Siding and other exterior trim is rarely salvage-
affects price, but it is not computed directly.
able because it’s usually old and weather-beaten.
Roofing and siding materials are often sold in
Barn board, in vogue years ago, is hardly charm-
squares of 100 sq. ft. Most yard lumber is sold in
ing when it is half-rotted, warped, and crawling
board feet (bd. ft.), according to this formula:
with carpenter ants. If there is any danger of
destroying a piece of salvage by removing it,
width (in.) × thickness (in.) × length (ft.)
leave it alone. Parts of many beautiful old places
12
that were restorable have been ruined by people
In the two examples below, each board con-
who didn’t know what they were doing.
tains 1 bd. ft.:
Moreover, if you have any qualms about the
structural strength of a building, stay out of it.
[EQ]12 in. × 1 in. × 1 ft. = 1 bd. ft.
Dismantling a building is a special skill, and inex-
12
perienced people who undertake the task can get
hurt. Perhaps the best advice for would-be users
[EQ] 6 in. × 2 in. × 1 ft. = 1 bd. ft.
of salvage materials is to buy it from a salvage
12
yard. In this case, somebody h
as already done the
dirty and dangerous work of removal.
In each of the following two examples, the
dimensions given yield 2 bd. ft.:
Engineered Lumber
[EQ]12 in. × 1 in. × 2 ft. = 2 bd. ft.
Like any natural product, standard lumber is
12
quirky. It has knots, holes, and splits, and it
twists, cups, and shrinks. As mature old-growth
[EQ] 2 in. × 4 in. × 3 ft. = 2 bd. ft.
timber was replaced by smaller, inferior trees,
12
When calculating the total board feet of sever-
al pieces of lumber, multiply the numerator (top
part) of the fraction by the total number of pieces
needed. Thus, here’s how to calculate the board
seven steps for on-site salvage
feet of 10 pieces of 2-in. by 6-in. by 12-ft. lumber:
if you are determined to do on-site salvage, here are a few suggestions:
[EQ]2 in. × 6 in. × 12 ft. × 10 = 120 bd. ft.
get a tetanus shot, and wear a long-sleeved shirt, heavy pants, thick-soled
12
shoes, safety glasses, disposable respirator, sturdy work gloves, and hard hat.
always cut electrical power to areas being demolished or dismantled. then use
Salvage Lumber
a voltage tester in outlets, fixtures, and switches to make sure there’s no current
flowing through them.
Salvage materials have striking advantages and
don’t hurry. Look at construction joints closely and disassemble pieces slowly.
disadvantages—the major plus being low cost;
as you free each piece, remove nails immediately. remember, footing on con-
the major minus being prep time. Salvaging
molding, flooring, and other materials from your
struction sites is chancy at best, and you don’t want to land in a bed of nails when
own home is a good way to match existing mate-
descending from a ladder in a hurry.
rials, but be picky in selecting materials from
if the piece is complex, such as a fireplace mantel, photograph it and then
other sources.
label each element before removing it.
Reuse centers are popular these days. For
before cutting into framing lumber, scrutinize it for nails. the best tool for
example the ReStore® resale outlets by Habitat
cutting through both lumber and nails is a demolition blade (see p. 48) in a recipro-
for Humanity® offer tax deductions to donors
cating saw. safety glasses are a must.
and recycled building materials at a fraction of
most salvaged wood is old and very dry, so get it under cover at once. Left