Wood Flashcards
<p>Structural/rough carpentry includes</p>
<p>structural framing, sheathing, blocking, anything to prep for finish work</p>
<p>Wood/lumber/timber</p>
<p>wood = comes from treeslumber = product of sawing, planing, etc.timber = at least 5 in. min. section</p>
<p>Adv./Disadv. of lumber</p>
<p>good: low cost, low footprint, easy to work, good insulator</p>
<p>bad: non-uniform, low strength, susceptible to moisture</p>
<p>Softwood vs. hardwood</p>
<p>soft: conifers (used for rough)</p>
<p>hard: deciduous (used for finish)</p>
<p>Lumber strength</p>
<p>depends on grain direction relative to load; best when load and grain parallel (eg., load on wood column); worst in bending</p>
<p>Lumber defects</p>
<p>knots (branch/limb), checks (growth rings are separated, pulled apart), pitch pocket (same as check, but filled w resin), shake (like check, but lengthwise instead of across grain), split (like check, but goes through piece of lumber, often at ends), wane (where bark was, or where chunk is just gone, usu. at corners)</p>
<p>warping: out of plane; bow warp - parallel, crook warp - side to side, cup = along width</p>
<p>Lumber grades</p>
<p>made by American Lumber Standards Committee; yard lumber: for structural/rough; factory/shop lumber: for finishing</p>
<p>Yard lumber</p>
<p>boards (less than 2), dimension (2 to 5), timber (more than 5)</p>
<p>2x2s, 2x4s (subdivided), 2x6s+</p>
<p>beams/stringers: 5" wide, 2"+ depth</p>
<p>posts/timbers: 5x5, depth not more than 2" than width</p>
<p>Factory lumber</p>
<p>grade B/better (best), C/select, D/select</p>
<p>common grades:Âno.1-no.5 (1 = best, usu. based on knots)</p>
<p>Nominal/Actual dimensions</p>
<p>1"=.75"</p>
<p>2-6=2.5-6.5</p>
<p>8-12=7.25-11.25</p>
<p>Moisture content</p>
<p>expressed as fraction of the overall weight of oven-dried wood; 30% = fiber saturation = when no water in cell cavities, but cell walls saturated = pt. when shrinkage starts to occur</p>
<p>Wood seasoning</p>
<p>Putting lumber on site, so it has time to shrink/swell to local/prevailing moisture content levels</p>
<p>Dry lumber</p>
<p>moisture content below 19% (req'd for structural lumber design values)</p>
<p>kiln dry = below 15%</p>
<p>Wood shrinking/swelling</p>
<p>occurs most perpendicular to grain, very little parallel to grain, most tangentially to growth rings, half as much radially</p>
<p>Wood stud construction</p>
<p>aka light frame wood construction, 2x4s or 2x6s, with a few heavier beams of built-up/heavy timber/steel members; can be platform (easier to construct)Âor balloon framing (less vertical shrinkage, stays parallel to wood grain)</p>
<p>Wood to masonry wall</p>
<p>hung by wood ledger + metal joistÂhanger or use fire cut (to prevent masonryÂfrom being pushed up/out when beam burns out)</p>
<p>Plywood ratings</p>
<p>thin wood veneer sheets glued together, usu. 4'x8', in .25"-.75" thickness, graded by span (measures stiffness/strength of parallel to face grain - eg 32/24, max dist. roof supports/max dist. floor supports, average residential conditions), also graded by wood species (I = group I woods, II = woods 2, 3, 4), graded by quality of face veneer (N natural finish, heartwood/sapwood, free of defects, A, B plugged knotholes, C small knothole/splits, D large knotholes); can have special glues/finishes for tough environments</p>
<p>Types of plywood</p>
<p>sheathing = attached to framing to provide structural support</p>
<p>particleboard = small wood particle/fibers/chips (low/med/high density), mostly for backing</p>
<p>OSB = oriented strand board - precision cut wood strands of 4" length, .0027" thick, layered at right angles, comes in bigger panels, subject to delamn.</p>
<p>MDF = medium density fiberboard - fibers made by steaming wood, most dimensionally stable panels, smooth face for finishing</p>
<p>hardboard = inter-felted fibers, can be tempered for hardness</p>
<p>Blocking, bridging</p>
<p>blocking = pcs btwn framing for rigidity or nail base</p>
<p>bridging = bracing btwn joists to prevent joist buckling (can be wd blocking or metal cross braces), usu 8' + o.c.</p>
<p>firestops = barriers in concealed framing spaces, can be 2"+ wood, gypsum, mineral wool</p>
<p>Engineered wood</p>
<p>smaller/waste woods to make stonger, bigger members; glue/metal fasteners/insulationÂused; includes plywood web joists (TJIs) (less wasteful, stronger, less shrinkage), laminated veneer lumber/structural composite lumber (thin lams parallel to length), trusses, SIPs panels, composite decking, CLTs cross-laminated timbers, glulams</p>
<p>Wood truss types</p>
<p>king post, queen post, Fink, scissor, Warren, Howe Pratt</p>
<p>SIPs</p>
<p>structural insulated panels: usu. OSB + EPS (expanded polystyrene)</p>
<p>other facings: plywood, Al panels, cement board, gypsum wallboard</p>
<p>other insulation: extruded polystyrene (XPS), urethane foam, compressed straw</p>
<p>thicknesses btwn 4.5"-12.25", usu. 4'x8' to 9'x28'</p>
<p>reduce construction time, improved insulation values bc reduced air infiltration, higher strength, flatter surfaces, dimensional stability</p>
<p>problems w/seismic anchoring, vapor barrier placement, insect damage</p>
<p>Composite wood decking</p>
<p>wood-plastic composite - planks formed from ~50%Âsm. wood fibers or wood flour mixed w ~50%Âplastic (polyethylene), along w/ colorants, stabilizers, fungicides</p>
<p>lasts longer than dimensioned lumber, stronger, splinter-free, recycled materials</p>
<p>hotter underfoot, warp prone</p>
<p>Cross-laminated timber</p>
<p>CLT, layer dimensioned lumber at right angles to make panel, very strong, resist bending, racking, act as strong diaphragm, can use smaller diameter trees since acting togther (green)</p>
Heavy timber construction
Main framing members of bldg from large dimensioned wood or engineered wood
Glulams
Glue-laminated wood members; depths are multiples of 1.5" (2xs), higher allowable stresses bc members defect free, dried, etc.; specified by stress rating; grades are industrial (rough), architectural (medium), premium (finest)
Wood decking
aka planking, solid or lam timber spanning btwn beams, usu. TNG, spans more than sheathing (4'-20'), can be both structural & finish floor/ceiling (but hard to conceal insul, services
= heavy tiber constr.!
Wood fasteners
nails (weakest, most common - box, common wire, wire spikes), screws (flat/round head, threading makes stronger cnxn, lead holes make stronger, lag = pointed end but head like bolt), bolts (use washer at head to distribute load), metal fasteners (lightweight connectors, timber conn., split rings, shear plates to transfer loads, gang nail plates), etc.
use nailing schedule for size, number, spacing, penetration type
Wood treatments
preservatives brushed, dipped or pressure applied to fight moisture + insects
creosote (coal tar, water proof, RR ties, marine structr.), oil-borne (penta/pentachlorophenol, for utility poles, pilings, bridges, long spans over swimming pools), water-borne (ACQ/ammoniacal copper quaternary, sodium borate/SBX, etc., lesser VOCs, paintable, but don't use w Al bc corrosive); treat all cuts w 2% copper in copper naphthenate
no longer used: CCA/chromated copper arsenate, ACZA/ammoniacal copper zinc arsenate bc of arsenic content, but were less corrosive
Finish carpentry includes
factory finished items like finished cabinetry &Â shelving, wall paneling, custom doors; also exterior siding, interior trim, stair framing, door &Â window framing
Common hardwoods
red &Â white oak, mahogany, birch, ash, walnut, cherry, poplar, maple
Finish carpentry grading
by Western Wood Products Assn (WWPA): selects (B/better, C/select, D/select), finish (+superior, prime, E), paneling, commons, alternate boards (+ VG = vertical grain)
Lumber cutting
plain sawing = cutting straight across the end of the log, makes 'cathedral' shape, least expensive quarter sawing = cutting into quarters, then relatively perpendicular to grain rift sawing = quartering, then radially cutting to stay 90 to saw cut, stays parallel to grain, most expensive
Wood siding
bevel (shingle), shiplap (bad at moisture drip), rabbeted bevel, square edge TNG, v-TNG (good at moisture drip), channel rustic - usu. softwoods bc of natural insect repellent (redwood, cypress, cedar)
Architectural woodwork
items made in factories where control is greater than in the field (machines!) - graded by the American Woodwork Institute (AWI): grade I, II, III, also premium, custom, economy grade for construction standards
Types of veneer cuts
plain slicing = plain sawing
quarter slicing = quarter sawing
rotary slicing = oblong shapes (least waste)
half-round slicing = less oblong shapes, as log it cut in half before (less than even plain slicing)
rift slicing = quartered, cut at 15 deg, reduces medullary rays (radial cells in oaks)
source log = flitch
Cabinetry door/drawer types
flush (expensive, need field/shop skill & good materials), flush overlay (millshop needs to be skilled), reveal overlay, reveal overlay
Types of veneer matching
bookmatching = most common, as if a book opened, slip matching = consecutive sliced placed side by side, random matching = no particular sequence, even from separate flitches
running match = bookmatches finish wherever, uneven ends
balance match = each veneer pc is equal in length
center match = ends of panel have equal veneer pcs
Types of veneer panel matching
not matched/premanufactured = least expensive, field cut around openings
sequence matching = panels made for job, attempts to keep grain continuity (loses at openings a bit)
blueprint matching = made for job, at openings, very litte grain continuity lost
Stile & rail panels/doors
vertical = stile, horizontal = rail, may have grooves to hold panel = sticking, center = panel, may have rim around it, held on by wood clips, z-clips or screwed to grounds (battens)
Plastic laminates
common = plam, HPDL, high pressure decorative laminate, phenolic resins w/ melamine resin on top
types of plam = colorthrough (no visible backing), fire-rated (adhesive, substrate less flammable), chemical-resistant (lab-grade, non-corrosive), static-dissipative (for high traffic, electronics, non-conductive), metal-faced (look like metal, v fragile), natural wood (thin veneers of actual wood)
Thermoset decorative paneling
surface is fused into backer, aka low-pressure laminates, melamine, don't delaminate (so, restroom stalls), but lower quality, so don't use in high traffic areas
Code reqmts for woodwork
limit the use of wood panels, ceilings, but not cabinets, based on occupancy, etc.
Finish on woodwork
field or factory finished; sanding &Â fillers for flatness, bleached or distressed to achieve a look
lacquer: nitrocellulose, hard & shiny;Â varnish: resins in a volatile, can be opaque; polyurethane: hard, durable, variety of solid/matte; polyester: hardest, most durable, difficult to repair
water-reducible acrylic lacquer, conversion varnish (most common transparent finish), catalyzed vinyl: very chemical & abrasion resistant, penetrating oil, stains (water & solvent based - water raises the grain, solvents dry quicker so do not raise the grain)
