Chapter 6 Wood work Flashcards Preview

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Flashcards in Chapter 6 Wood work Deck (75):
1

Bark

Outermost protective layer (A: dead, B: living)

2

Cambium Layer

Source of new wood cells

3

Sapwood

Living cells that store and transport nutrients

4

Heartwood

Dead cells that contribute to structural strength

5

Pith

Innermost, first year’s growth

6

Annual Growth Rings

Result from differences in rate of tree growth and density of cells, from spring to summer

7

Soft Woods

-From cone-bearing (coniferous) trees
-Generally, plain figure (pattern of grain and surface features)
-Mostly originating from North American forests
-Fast-growing, plentiful, relatively inexpensive
-Generally soft, easily worked
- Not all softwoods are soft Douglas Fir is harder some hardwoods

8

Softwood uses

-structural wood products
-finish trim, shingles and siding
-flooring

9

Hardwoods

-From broadleafed (deciduous) trees
-Often more interesting figure
-Harvested from around the world
-Slower growing, generally more expensive than softwoods

10

Hardwoods Softer

Denser, with greater variety of colors and figure
fine trim, paneling
flooring
fine cabinet work, furniture

11

Certified Wood

-Sustainable forestry management
-Protect forest ecosystem
-Maintain long term forest economic viability
-Some programs also address social responsibilities, for example, the land rights of indigenous peoples.

12

Forest Stewardship Council (FSC)

Only certifying organization currently recognized for LEED certification

13

Plain Sawn Cut

growth rings roughly parallel to wider face of board

14

Quarter Sawn Cut

growth rings close to perpendicular to wider face of board

15

Rift Sawing Cut

cuts made radially to center of tree

16

Plain Sawn Lumber

-Broader grain pattern on wide face
-Greater distortion during drying
-More uneven surface erosion or wear
-More efficiently sawn from log; less costly
-Also called flatsawn, flat grain

17

Quarter Sawn Lumber

-More narrowly spaced grain pattern on wide face
-Less distortion during drying
-More even surface erosion or wear
-More costly to saw from log

18

Rift Sawn

-Riftsawn (left): angle of grain falls between perfectly quarter sawn and plainsawn
-Also called edge sawn, edge grain, vertical grain

19

Seasoning

-After lumber is sawn, it is seasoned (dried), either in air or in kilns.
-Seasoned lumber is lighter, stronger, and stiffer than green (unseasoned) lumber.
-Decay causing fungi cannot survive in wood with a moisture content (MC) below 20%.

20

Equilibrium Moisture Content

Wood eventually dries to equilibrium with the surrounding air, reaching its equilibrium moisture content (EMC).
EMC for exterior uses: 15% - 19%
EMC for interior uses: 5% - 11%

21

Surfacing

Lumber is surfaced to make it smooth and more dimensionally precise.
-Framing lumber: usually surfaced four sides (S4S)
-Finish lumber: may be S4S, or surfaced two sides (S2S), the other sides to be sawn and surfaced by the woodworker
-Surfacing after seasoning (S-DRY): removes some drying distortions
-Surfacing before seasoning (S-GRN): sometimes more economical; best for wood species that don't distort excessively as they dry
-Construction planking: unsurfaced, resulting in a plank that is stronger (no material has been removed) and more slip-resistant

22

Structural Properties of Wood

-Wood has both useful tensile and compressive strength.
-Strength varies significantly with direction of grain, species, and presence of knots or other defects.
-Defect-free wood is close to the strength of steel on a per-weight basis, but typical grades are weaker.
-Strength also varies with duration of load, moisture content, chemical treatments, temperature, size and shape of piece.

23

Lumber Dimensions

-Actual sizes are less than nominal size. E.g.:
-1x4 actual size is approximately ¾" x 3½"
-2x4 is 1½" x 3½"
In U.S., lumber is priced by the board foot, based on nominal, not actual dimensions:
-12 sq. in. nominal cross-section, 1 foot long = 1 board foot

24

Standard Wood Sizing

-As woodwork lumber is made in standard thickness, reducing waste by using standard sizing is good practice.
-Lumber for millwork is measured in ‘quarters’, which refers to ¼” increments.
-Example: 5/4 lumber is nominally 1-1/4” thick

25

Plywood

Panel product made from an odd number of layers of thin veneer glued together under heat and pressure
-Each layer is laid perpendicular to the previous one, providing much greater strength than a solid wood piece of similar dimension
-Commonly used in finish carpentry, sometimes in millwork construction
-Graded based on quality of face veneer
-Grades N, A, & B used in interior construction, only N is suitable for natural finishes; A is used for painted finishes, and B is used for utility work, etc.
- Composite and laminated wood products are much more dimensionally stable than solid wood

26

Molding

- Trim used for decorative or functional purposes
- Hundreds of profiles available, Fig. 6.1 shows some common shapes

27

Gluing for Width

- Gluing for width requires either a ‘tongue and groove’ (shown) or a ‘spline joint
- ‘reveal’ detail is incorporated into design. This is common practice, as it reduces splitting of the corner fibers of the pieces, and allows for minor alignment imperfections

28

Veneer

- Thin slice of wood, glued to backing material; particleboard, MDF, and plywood used to hold it flat, provide solid substrate

29

Flitch

individual veneers that come from the same piece of a log.

30

Methods of Cutting Veneer

-Rotatry Slicing
-Plain Slicing
-Quarter Slicing
-Half-Round Slicing
-Rift Cut

31

Rotary Slicing

log is spun on lathe, very pronounced grain, least waste

32

Plain Slicing

growth rings roughly parallel to wider face of board

33

Quarter Slicing

growth rings close to perpendicular to wider face of board

34

Half- Round Slicing

: similar to rotary slicing, log is cut in half; characteristics similar to rotary, plain-sliced veneers

35

Rift Cut

: log is quartered, then sliced at slight angle to growth rings; accentuates growth rings, vertical grain

36

Cabinetwork

Includes custom-manufactured built-in base and upper cabinets, freestanding fixtures, custom shelving
Many types of joints used for millwork construction to increase strength, improve appearance
In most cases, it is possible to eliminate mechanical fasteners (nails, screws) with good joinery design

37

Countertop Construction

-Each layer is laid perpendicular to the previous one, providing much greater strength than a solid wood piece of similar dimension
-Commonly used in finish carpentry, sometimes in millwork construction
-Graded based on quality of face veneer
-Grades N, A, & B used in interior construction, only N is suitable for natural finishes; A is used for painted finishes, and B is used for utility work, etc.
-Composite and laminated wood products are much more dimensionally stable than solid wood

38

Drawer and Door Front Construction

Hundreds of profiles available, Fig. 6.1 shows some common shapes

39

Flush Construction

drawer/door face installed flush with face frame; requires extra care in construction, should be installed with adjustable hinges, drawer glides

40

Flush Overlay Construction

fronts of doors/drawers overlap face frame of cabinet; only doors and drawers are visible, all are flush with each other. Should be installed with adjustable hinges, drawer glides

41

Reveal Overlay Construction

door/drawer fronts separated to reveal face frame behind; reveal varies per design preference. Less expensive, typical of ‘off the shelf’ residential cabinets

42

Upper Cabinet Construction


- Not as deep as base cabinets
-Underside must be considered as it is visible
-Residential construction with wood construction allows screws through cabinet back into studs; metal stud systems common to commercial construction require blocking between studs, before framing is covered with gypsum board
-Top of cabinet may be detailed against ceiling, dropped soffit, or space may be left above cabinet
-Doors may extend below bottom, to allow finger pull, or to conceal reinforcing member/light fixture concealment trim below cabinet

43

Shelving

-May be mounted on adjustable metal standards, attached to floor mounted cases, or built into wall-hung cases; can also be fitted with doors
-Many options for edge treatment possible
-Fixed shelving attached with stop dadoes or concealed, interlocking fastening devices in Premium and Custom grade shelving
-Economy grade shelving uses through dadoes for fixed shelves

44

Panel Types

- Flush Panels
- Stile and Rail Construction

45

How are panels generally attached ?

-Wood cleats or Z-clips
-Occasionally, screwed to wall, if trim elements cover fasteners, or if exposed fastener system designed as integral to composition
-At ceilings, sufficient space for installation over cleat or Z-clip is necessary; usually 3/4” depending on clip size – can be filled or covered with trim if desired

46

Panel Construction

-Flush Panels: smooth surfaces with little trim
-Edges between panels can be treated as flush joints, which are joined with splines, or with reveals between panels
-Tight joints should have V-joints or reveals cut into panels to make cracks, movement less noticeable; in humid environments, joint should have gap to allow for expansion/contraction

47

Stile and Rail Construction

-Consists of a frame of solid wood that contains individual panels
-Traditionally, each panel was made from solid wood; now, most panels veneered
-Attachment to wall similar to flush panels; sometimes screwed to wall, with molding covering screws, with panels doweled or splined together.

48

Stiles

Vertical frame pieces

49

Rails

horizontal pieces

50

Sticking

Panels are held in place with grooves cut into frame sides, or with individual molding pieces

51

Book Matching

most common; as veneers sliced off log, every other piece is turned over, so adjacent leaves form symmetrical pattern

52

Slip Matching

consecutive pieces placed side by side with same face sides being exposed

53

Random Matching

veneers placed in random sequence, veneers from different flitches may be used

54

Runnning Match

alternates pieces regardless of width

55

Warehouse matching

- least expensive
- assembled from a single flith that yields 6 to 12 panels
- field cut to fit around the doors, windows . and other obstructions, resulting in some loss gain continuity
- doors and cabinets cannot e matched with paneling

56

Sequence match

- uniform width manufactured for a specfic job and job with the veneers arranged in sequence
-trimmed to fit around doors and other obstructions, there is moderate loss of gain continuity
- doors and cabinets cannot be matched with the paneling

57

blueprint matching

-most expensive
- fit the room precisely and to line up with every obstruction so the grain continuiy is uninterrupted
- veneers from the same flitch are matched over door doors, cabinets and others veneer-covered items

58

High- Pressure Decorative Laminates (HPDL)

-often called ‘plastic laminate’
-Commonly uses MDF substrate; flatter, more expensive than particleboard. MDF is dimensionally stable. Specify formaldehyde-free MDF whenever possible.

59

Laminate Type

General purpose (GP50)
General purpose for vertical surfaces (GP28)
Postforming (PF30, PF 42)
Cabinet liner (CL20)
Backing Sheet (BK20)

60

Specialty Laminates

Specialty laminates
Colorthrough laminates
Fire-Rated laminates
Static dissipative laminates
And many others

61

Special Woodwork Items

- Doors
- Upholestered Wall Systems
- Solid Surface Materials

62

Doors

Custom doors, exotic veneers, blueprint matching, specially designed doors commonly constructed by millworkers

63

Upholestered Wall Systems

Acoustic fabric-wrapped panels often fabricated, installed by woodwork contractor

64

Solid Surface Materials

-Homogeneous, polymer-based surface material; made of filler & clear resin binder
-Commonly used for kitchen sinks, countertops, places where plastic laminate used
-Expensive, but quite durable, easy for millworkers to fabricate with same tools as woodwork

65

Finishes

- Opaque Finishes
-Transparent Finishes

66

Opaque Finishes


-Laquer
-Varnish
-Polyurethane
-Polyester

67

Lacquer

-high nitrocellulose content, modified with resins
- easy application, low cost

68

Varnish

resinous material dissolved in volatile liquid
- easy application, low cost

69

Polyurethane

synthetic finish, very hard, but difficult to repair
- most durable finishes; most expensive; dull to full gloss available in polyurethane

70

Polyester

synthetic finish, hardest, most durable finish, difficult to repair
-most durable finishes; most expensive
; polyester is full gloss only

71

Transparent finish

-Lacquer and varnish
- Vinyl
- Oils
- Polyurethane and Polyester
- Stains

72

Oils

- traditional method, easy to apply, darken with age, require periodic re-oiling

73

Vinyl

- more chemical resistance than lacquer & varnish; scratch/abrasion resistant

74

Stains

- applied prior to final finish to change color, appearance of wood; water & solvent based stains available

75

Millwork

Finished carpentry components, such as moldings, doors, cabinets, stairs, etc. manufactured off-site