MATERIALS - WOOD Flashcards
WHAT WOOD DEFECT IS A KNOT
BRANCH OR LIMB
WHAT WOOD DEFECT IS A CHECK
Result Of Improper Seasoning. Checking is cracking that develops along the radius of a log. It rarely extends through the beam to the other side,
WHAT WOOD DEFECT IS A PITCH POCKET
OPEN AREA BETWEEN GROWTH RINGS THAT CONTAINS RESIN
WHAT WOOD DEFECT IS A SHAKE
LENGTHWISE SEPARATION OF WOOD USUALLY OCCURS THROUGH THE ANNUAL GROWTH RINGS heart shake, star shake, ring shake Shake is a timber defect. It occurs around the growth rings of a timber and is often found in older trees that grow in wet areas.
WHAT WOOD DEFECT IS A SPLIT
SIM TO CHECK EXCEPT SEPARATION EXTENDS COMPLETELY THROUGH PIECE OF LUMBER, USUALLY AT THE ENDS.
WHAT WOOD DEFECT IS A WANE
PRESENCE OF BARK OR ABSENCE OF WOOD ON THE EDGE OF CORNER OF PIECE OF LUMBER
WHAT ARE the FIVE SIZE GROUPS OF YARD LUMBER
- 2 to 4 inch thick, 2 to 4 inch wide
- 2 to 4 inch thick, 4 inch wide, category for 2 x 4
- 2 to 4 inch thick, 5 inch wide and wider
- more rectangular …Beams and stringers, 5 inches wide and wider, min of 2 inches more than width deep
- more square ..Post in Timbers, members 5” x 5” and larger with the depth max than 2 inches greater than the width
What Are Select Grades For Board Lumber
Select grades:
A - Does not exhibit knots, splits or visible defects.
B - A few small visible defects.
C - Small knots, but one side may be completely clear of defects.
D - May contain pin knots and other small blemishes.
actual dimension of 2x4?
1-1/2 x 3-1/2
actual dimension of 2x10?
1-1/2 x 9-1/4 (changes from 1/2” to 3/4” at 7” wide)
Sheathing
thin panel material attached to framing to provide lateral support, increased rigidity, provide base for applying exterior finishes.
Oriented strand board OSB
engineered panel product from cut wood strands maximum 4 inches long.
Plywood
manufactured from thin layers or “plies” of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another.
Plywood graded in two ways
-First is by span rating 2 numbers: 32/24 first for roof second for floor, spanning perpendicular to the direction of supports and if panels are continuous over 3 supports. -Second by Quality of face veneer.
Particleboard
composed of small wood particles, fibers, or chips of various sizes mixed together in a binder informed under pressure into a panel
Hardboard
panel product composed of inter-felted fibers consolidated under heat and pressure. Available sanded on one or both sides either tempered untempered.
Medium density fiberboard MDF
from wood particles reduced to fibers. In a moderate pressure steam vessel then combined with the resin and bonded together under heat and pressure. The most dimensionally stable of the mat-formed panel products.
Plywood web joists
For the same depth they have a much higher load carrying capacity then wood joists, very efficient. Minimal shrinkage, ease of handling, uniformity of size and shape
Cross-laminated timber (clt)
layering dimension lumber is right angles to form structural panel. Like plywood CLT is formed from odd numbers of layers typically 3, 5 or 7. Panels are custom manufactured in range from 2 feet to 10 feet wide and up to 50 feet long. Very strong. Resist axial bending and wrecking loads and provide time from action for lateral loads spans up to 25 feet.
Parallel strand lumber ( PSL)
made by bonding long, narrow would strands together on the heat and pressure using waterproof adhesive. Proprietary product PARALLAM
Laminated veneer lumber (LVL)
thin glue laminated framing. Gluing thin veneers of lumber together to build up strong with your dimensionally stable framing member
Glued laminated construction / glulams
individual pieces or lumber glued together and finished on the factory conditions for uses beams, columns, purlins and other structural components. Heavy loads and long spans. In most cases 1-1/2” actual depth pieces are used so overall depth is some multiple of 1-1/2”,
Planking / decking
solid or laminated timber. Available in nominal thickness of 2, 3, 4, and 5 inches (actual sizes vary - manufactureD OF solid or laminated). tongue-and-groove edging, unlike sheeting, planking is intended to span greater distances between beams rather than between closely spaced joist. Common spans range from 4 feet to 20 feet.
