Renovation 4th Edition

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Renovation 4th Edition Page 18

by Michael Litchfield

T-straps and L-straps are face-nailed to members

  joining in a right angle.

  Framing angles are used extensively to reinforce

  Caps and bases: 1. A CBSQ44 post base anchors a 4x4 to concrete; 2. BC6 post cap and base;

  wood connections at 90° intersections. For seis-

  3. AC6 post-to-beam connector, which can be attached after the members are in place;

  mic strengthening and on shear walls, framing

  4. BC460 half-base; 5. BC46 post cap and base

  angles help prevent floor framing from slipping

  off walls and supports during an earthquake.

  hold-downs are massive steel brackets that

  anchor framing to foundations and, when used

  with long threaded rods, join framing on differ-

  ent floors. When retrofitting to a foundation, use

  epoxy to attach hold-down bolts to concrete, as

  shown in the right photo on p. 252.

  Clips vary by function. H-clips are an alternative

  to solid blocking when installing roof sheathing.

  They also act as 1⁄16-in. spacers so roof sheathing

  can expand. Drywall clips allow you to eliminate

  some blocking in corners, but it’s best to use

  these clips sparingly; solid blocking is much

  sticky nameS

   CauLKiNG was the first on the market, so

  that’s the default word for materials that fill

  gaps and keep out weather.

   SeaLaNtS generally refer to high-performance

  compounds such as silicones and polyurethanes.

   aDHeSiVeS stick things together; their fancy

  name is quite a mouthful: elastomer-based

  Made of 16-gauge steel, nail plates protect plumbing pipes and electrical wires from being

  extrudable mastics. eLaStoMer indicates that

  punctured by nails.

  the product will stay flexible and rubbery, and

  MaStiCS is a general term denoting any pasty or

  gooey adhesive. that noted, adhesives also seal

  and sealants adhere, although that’s not their

  main mission.

  74

  chapter 4

  stronger. Deck clips are nailed to deck joists, and

  A number of factors should determine your

  P R O T I P

  then 2x4 decking is driven onto the sharpened

  choice of adhesives: the materials being joined,

  point of the clip. You can lay down decking with-

  strength, durability, flexibility, shrinkage, job-site

  choosing the right adhesive

  out having to face-nail it; the clip also acts as a

  conditions (especially temperature and humidi-

  is tough. these compounds

  spacer so that water can clear.

  ty), workability, curing time, ease of cleanup,

  are cutting-edge chemistry.

  odor, and—increasingly important—an adhesive’s

  Post bases and caps provide strong connections

  Formulations of familiar brands

  toxicity and green profile. Accordingly, there is

  while eliminating the need to toenail posts,

  change often—and often with-

  now a wide selection of solvent-free, low-VOC

  which tends to split them. Post bases are typical-

  out warning. so here are four

  adhesives that are nontoxic. To help you make

  ly set in concrete, with posts then bolted or

  commonsense tips: (1) use

  your choice, many manufacturers now offer

  nailed to the base. Bases also reduce post rot, for

  manufacturers’ online product

  interactive, online product selectors.

  selectors to narrow your choice

  their raised standoffs elevate the post and double

  As a rule of thumb, both solvent-free and

  of adhesives. (2) get friendly

  as a moisture shield. Post caps resemble a pair of solvent-based adhesives have the same holding

  with the resident adhesive expert

  U-brackets set at right angles to each other: One

  power once they’ve cured. However, it should be

  at the lumberyard, who may have

  U, upside down, straddles the top of the post,

  noted that solvent-free adhesives, which cure by

  gotten a lot of feedback from the

  while the other, right side up, receives the beam

  field. (3) test a tube before you

  evaporation, can be affected by rain and job-site

  on which the joist will sit.

  buy a case. (4) “but it’s cheap” is

  temperatures outside a range of 40°F to 100°F.

  Miscellaneous metal connectors are often

  always a fool’s bargain.

  Also, solvent-free adhesives may set poorly

  needed. Where you absolutely must notch stud

  between two nonporous surfaces and won’t bond

  edges to accommodate plumbing, a metal shoe

  to some metals. On the other hand, solvent-based

  plate reinforces the stud and protects the pipe

  adhesives, which cure via a chemical reaction,

  from errant nails. Speaking of protection, this

  discussion would be incomplete without men-

  tioning nail plates, which protect wires and pipes

  from stray nails when finish walls go up.

  Adhesives, Caulks,

  and Sealants

  Common adhesives, caulks, and sealants look

  the same, but their formulations are complex

  and carefully formulated for specific materials

  and expected conditions. They all generally come

  in 10-oz. cartridges that fit into an applicator

  (caulking gun). You simply cut the cartridge

  nozzle to the desired diameter and squeeze the

  long pistol-grip trigger to lay down beads of

  the stuff.

  construction adHesives

  Construction adhesives bond to a variety of mate-

  rials, including standard lumber, treated lumber,

  Four popular adhesives, followed by their chemical names. From left: Gorilla Glue (polyurethane),

  plywood and OSB panels, drywall, wall paneling, Gorilla Super Glue (cyanoacrylate), Weldwood® plastic resin (urea formaldehyde), and Titebond II rigid insulation, concrete and masonry, tile,

  wood glue (polyvinyl acetate).

  metal, and glass.

  Construction adhesives are a boon to builders.

  Instead of nailing sheathing every 6 in. around

  Epoxy resins are typically mixed from

  two components, whether as a paste

  panel edges and every 10 in. in the field, builders

  mixture used to fill sizable areas or as

  using adhesives need nail only every 12 in. Being

  a dual-cylinder injector where the

  flexible, adhesives fill surface irregularities and

  ingredients meet at the point.

  double as sealants. Structurally, panels bonded

  with adhesive are stiffer and capable of bearing

  greater loads than panels that are only nailed.

  Floor sheathing and stair treads bonded with

  construction adhesives are far less likely to flex,

  pop nails, or squeak. Drywall ceiling panels

  bonded with adhesives do a better job of deaden-

  ing sound and cutting air infiltration.

  building materials

  75

  can bond to most surfaces and are little influ-

  seaLants and cauLks

  enced by temperature or the presence of water.

  As noted in “Sticky Names” on p. 74, sealants and
/>   Chronic exposure to airborne VOCs, however,

  caulks do pretty much the same thing: fill gaps,

  can cause serious health problems.

  keep moisture at bay, and reduce air infiltration.

  Sealants tend to last longer, perform better, and

  a potpourri oF adHesives

  cost more. Here’s a look at the strengths and

  Here’s a primer on common adhesives.

  weaknesses of three major types of caulk.

  Although caulks aren’t quite as diverse as con-

  Polyurethanes are a great all-purpose water-

  struction adhesives, they do have varying formu-

  proof adhesive, capable of bonding wood, stone,

  lations and properties. For specifics, go online or

  metal, ceramics, and so on. Strong, versatile, and visit your lumberyard.

  easy to use, polyurethanes such as Gorilla Glue®

  and PL Turbo™ are favorites with builders and

  Silicones are arguably the most durable and

  woodworkers. Because a chemical reaction cures most water-resistant of any caulk. They are espe-

  these glues, they are not affected by moist or oily

  cially suitable for window glazing and slick bath-

  surfaces; they can even join pieces that have

  room and kitchen surfaces.

  been finished. Before polyurethane glues dry,

   Advantages: Silicones are incredibly

  they can be removed by a solvent such as acetone tenacious on nonporous materials such as

  or mineral spirits.

  glass, glazed ceramic tiles, and metal. There’s

  little shrinkage, and they can be applied at

  Polyvinyl acetates (PVA) are a broad category of –40°F. Silicone sealants specified for metal

  glues that range from water-based brands such as flue pipe function at 500°F. And silicones have

  Elmer’s® white glue to Titebond® II and III, yel-

  the best long-term flexibility, UV resistance,

  low glues whose emulsions combine water and

  and weatherability. Also, molds won’t grow

  polymers. PVA glues are further divided into

  on them.

  three types: Type I is waterproof, Type II is water-

  resistant, and Type III is not water-resistant.

   Disadvantages: Silicones are messy to

  Beyond that, all PVA-glued joints need to be

  work with; wear rubber gloves to protect your

  clamped until they cure, and, once dry, they all

  skin. Once silicones have cured, it’s almost

  have about the same holding strength.

  impossible to remove them. Plus, they are

  P R O T I P

  bond breakers—that is, because nothing will

  Cyanoacrylates (CA) are one-part or two-part

  stick to an area they’ve tainted, think twice

  use the same gun to apply

  glues that set in 10 seconds to 10 minutes and

  about trying them on wood, concrete, or other

  caulking and construction adhe-

  include the popular brands Krazy Glue® and

  sive, but use a different tech-

  porous surfaces they don’t adhere well to.

  Super Glue®. Because they set strong and quick,

  nique. because caulks and seal-

  Avoid inhaling acetoxy silicones, and don’t use

  CAs are prized by carpenters working one-handed,

  ants fill gaps, push the gun away

  them on metal because they’ll corrode it. Pure

  say, to hold a miter joint in place until the glue

  from you as you apply them,

  silicones can’t be painted, although siliconized

  sets. More expensive and much faster setting

  pushing caulk into gaps. but to

  acrylics can.

  than polyurethane or PVA glues, CAs are not well

  get an evenly sized bead of con-

  suited to joining large surfaces.

  Polyurethanes are versatile multipurpose caulks

  struction adhesive, pull the gun

  toward you, in a “lazy s” motion.

  but are not as tenacious as silicones.

  epoxy resins are famous for their strength.

  

  Where two panels meet over a

  Advantages: Because they attach equally

  Typically mixed from two components, epoxies

  framing member, apply a tight

  well to wood, masonry, and metal, they’re

  can bond to materials on which almost nothing

  zigzag of adhesive so both edges

  good for caulking joints where dissimilar

  else will—that is, when the surface areas to be

  will seat well.

  materials meet. Polyurethanes won’t corrode

  bonded are small or when dampness is extreme.

  metal. They’re easy to work, although polys get

  Epoxy products are especially important in foun-

  pretty stiff as temperatures approach freezing.

  dation repairs and seismic strengthening (for

  Shrinkage is negligible. They’re great for

  more information, see chapter 10). Unlike most

  skylight flashing and metal roofs. And they can

  other adhesives, epoxies also maintain structural be painted. Also, they’re easier to work than

  strength across a gap.

  silicones, even though they’re solvent based.

  Styrene-butadiene is a good all-purpose exterior

   Disadvantages: Polyurethanes have poor

  and interior glue for joining materials of low

  UV resistance, but additives or painting can

  porosity, such as tile and masonry.

  improve that dramatically. Although they are a

  hot-melt glues are applied using an electric

  good all-purpose caulk, they don’t have the

  glue gun and are excellent for tacking surfaces

  durability or shelf life of silicones.

  quickly—they’re the glue of choice for building

  templates out of thin plywood strips (see

  chapter 13).

  76

  chapter 4

  30-lb. Live Load 10-lb. dead Load L/360

  Floor joists*

  S p a n ( f e e t a n d i n c h e s )

  2x6

  2x8

  2x10

  2x12

  Species

  S p a c i n g o n C e n t e r

  or group

  Grade

  12 in. 16 in. 19.2 in. 24 in. 12 in. 16 in. 19.2 in. 24 in. 12 in. 16 in. 19.2 in. 24 in. 12 in. 16 in. 19.2 in. 24 in.

  Douglas sel. struc.

  12–6

  11–4

  10–8

  9–11

  16–6

  15–0

  14–1

  13–1

  21–0

  19–1

  18–0

  16–8

  25–7

  23–3

  21–10

  20–3

  fir–

  no. 1 & btr. 12–3

  11–2

  10–6

  9–9

  16–2

  14–8

  13–10 12–10

  20–8

  18–9

  17–8

  16–5

  25–1 22–10

  21–4

  19–1

  larch

  no. 1

  12–0

  10–11

  10–4

  9–7

  15–10 14–5

  13–7

  12–4

  20–3

  18–5

  16–9

  15–0

  24–8

  21–4

  19
–6

  17–5

  

  no. 2

  11–10

  10–9

  10–1

  9–3

  15–7

  14–2

  13–0

  11–8

  19–10

  17–5

  15–11

  14–3

  23–4

  20–3

  18–6

  16–6

  no. 3

  9–11

  8–7

  7–10

  7–0

  12–7

  10–11

  10–0

  8–11

  15–5

  13–4

  12–2

  10–11 17–10 15–5

  14–1

  12–7

  Douglas sel. struc.

  11–3

  10–3

  9–8

  8–11

  14–11

  13–6

  12–9

  11–10

  19–0

  17–3

  16–3

  15–1

  23–1

  21–0

  19–9

  18–4

  fir

  no. 1

  11–0

  10–0

  9–5

  8–9

  14–6

  13–2

  12–5

  11–6

  18–6

  16–10 15–10

  14–5

  22–6

  20–6

  18–9

  16–9

  (South) no. 2

  10–9

  9–9

  9–2

  8–6

  14–2

  12–10

  12–1

  11–3

  18–0

  16–5

  15–5

  13–10 21–11

  19–8

  17–11

  16–1

  

  no. 3

  9–8

  8–5

  7–8

  6–10

  12–4

  10–8

  9–9

  8–8

  15–0

  13–0

  11–10

  10–7

  17–5

  15–1

  13–9

  12–4

  Hem-fir sel. struc.

  11–10

  10–9

  10–1

  9–4

  15–7

  14–2

  13–4

  12–4

  19–10

  18–0

  17–0

  15–9

  24–2

  21–11

  20–8

  19–2

  

  no. 1 & btr. 11–7

  10–6

  9–10

  9–2

  15–3

  13–10

  13–0

  12–1

  19–5

  17–8

  16–7

  15–5

  23–7

  21–6

  20–2

  18–3

  no. 1

  11–7

  10–6

  9–10

  9–2

  15–3

  13–10

  13–0

 

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