Renovation 4th Edition

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Renovation 4th Edition Page 14

by Michael Litchfield


  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

  12

  

  3⁄411⁄2

  Protection Agency (EPA) determined that CCA

  leaches arsenic into the soil. As a result, industry

  14

  

  3⁄431⁄2

  leaders agreed to stop using CCA treatment for

  16

  

  3⁄451⁄2

  most residential applications by the end of 2003.

  More benign types of pressure-treated lumber,

  18

  

  3⁄471⁄4

  such as alkaline copper quat (0.40 ACQ) and

  copper boron azole (CBA) are available. Both

  110

  

  3⁄491⁄4

  biocides are arsenic-free.

  112

  

  3⁄4111⁄4

  Whatever lumber treatment you consider,

  consult its product data sheets for the relative

  24

  

  11⁄231⁄2

  safety of the chemicals used and whatever care

  26

  

  11⁄251⁄2

  you should take when handling, storing, and

  cutting it. In fact, it’s smart to capture and safely

  28

  

  11⁄271⁄2

  dispose of the sawdust.

  210

  

  11⁄291⁄2

  212

  

  11⁄2111⁄2

  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

 

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