Construction Flashcards
1
Q
In low sloped roofs, drains should be placed-?
A
At midspan between structural supports (natural weak point that could cause ponding)
290 slope 1/4” / 12”
2
Q
Intensive green roof
A
Soil directly on roof- usually want a flatter roof
3
Q
Extensive green roof
A
Trays of plants that sit on a roof
45 degrees max for green roofs
4
Q
Blue roofs
A
Intentional holding water on roof for slower release
5
Q
Steep roof
A
2” per foot or greater is a steep roof - sheds water quickly - overlap small units to shed water ( shingles)
6
Q
Low slope roof
A
Slower drainage, higher likelihood of ponding. Membranes -for larger buildings
7
Q
Bituminous roofing
A
Asphalt based
Mod bit
Multiple layers of overlapping felt (built up)
Oldest type “
8
Q
Single ply roofing
A
Plastic membrane
EPDM
9
Q
Fluid- applied roofing
A
Sprayed membrane
Best for difficult geometry
10
Q
Pitch pan
A
Often leaks
Metal hole around a penetration, filled with sealant, supposed to shed water away
11
Q
Albedo
A
Solar reflectance
High albedo = high reflectance (light colors)
Min 0.65 to spec
12
Q
Emissivity
A
Infrared ; shedding heat - higher is better
13
Q
Sapwood
A
Carries nutrients to branches and leaves (sugar and water)
14
Q
Heart wood
A
Dead but contributes structurally _ hard wood part
15
Q
Rot resistant wood
A
Redwood, Cyprus, cedar, heartwood
16
Q
Cambium
A
Produces new bark and cells, under dead bark
17
Q
Pith
A
Center of tree
18
Q
Summerwood
A
Grows slower, more strength, darker rings
19
Q
Springwood
A
Grows faster, less strength, lighter rings
20
Q
Wood trim is made from?
A
Softwood
21
Q
Hardwood
A
Fine woodworking - deciduous broadleaf trees, encapsulated seeds like acorns
22
Q
Softwood
A
Structural, coarser, uglier gram, pine trees - non encapsulated seeds
23
Q
Deciduous trees
A
Hickory, maple, birch, beech, oak, ash, Black cherry, Black walnut, butternut, aspen, basswood, balsa
All hardwoods
24
Q
Coniferous trees
A
Spruce, white pine, yellow pine, larch, Red cedar, hemlock, redwood, Douglas fir
Softwoods
25
Modulus of elasticity
Measure of stiffness- means its a stronger species
26
Plainsawn wood
Cheaper- cuts are all made parallel to grain, more likely to warp, minimal waste, no need to reorient tree
27
Quartersawn wood
Wears better, stronger, harder, more expensive, some waste, more labor - cut in 1/4 then saw toward center
28
MC (wood)
Mc= moisture content ( (wet - dry ) / dry), x 100%
MC 15=15 % moisture, high structural quality
Mc 19=19% moisture
Dry wont warp
29
Green lumber
Not dried, dimensions will change
30
Wood check
Where the tree cracks as it dries
Like straws - fibers are long/lengthwise
31
Wanes
Irregular edges from sawing too close to perimeter of log
32
Wood strength
Compression is strongest
Bending less
shear least
33
Wood grades
A is structural - headers etc
A-low - blocking
Studs
Graded at strength and look
34
Flitch
Log used for veneer
35
Plain sliced veneer
Nicer looking, smaller pieces, like plain sawn
36
Quarter sliced veneer
Used for fine wood working, parallel grain, cut like quarter sawn
37
Rotary sliced veneer
Unroll like toilet paper - least expensive, can be used for plywood
38
Most likely to be used for wood decking and outdoor railing
Wood plastic composites (wpc)
39
Made from overlapping dimension lumber pieces adhered together
Glue laminated wood (glulam)
40
Made into large panels for floor, roof, walls
Cross-laminated timber (clt)
41
Web typically made from OSB
Wood i-joists (stc)
42
Strongest wood type
Parallel strand lumber (psl)
43
Least strong wood type
Laminated strand lumber (lsl)
Oriented strand lumber (osl)
44
Least expensive wood type
Laminated strand lumber (lsl)
Oriented strand lumber (osl)
45
more flexible than solid wood (needs closer - spaced supports)
Wood-plastic composites (wpc)
46
GIulam
Joining smaller strips together, stronger , can make longer, treated for outdoor
47
Cross-laminated timber (clt)
Alternating lumber at 90°, can make really strong big panels
Can cut any kind of large holes because of 2 way structure
48
Laminated strand lumber (lsl)
Not super strong, inexpensive, used for rim board, short span header - shredded wood strands glued together and compressed
49
Parallel strand lumber (psl)
Stronger, heavier, relatively expensive
50
Wood i-joists
Longer and stronger, use dimension lumber and OSB as web
51
Laminated veneer lumber
Layers of veneer until its as strong and thick as we need
52
Wood plastic composite
Less likely to shrink or warp more weather resistant, more flexible, shorter spans between beams required, stains easily
53
Board feet
Calculate cubic footage - quantifies amount of wood
54
Plywoods
Odd number of layers- front and back same grain - 4x8 sheets
55
Fiberboard
Smallest wood fibers glued together with resin - interiors only, dimensionally stable, stiffer, and can handle fasteners without splitting
Mdf-medium density fiber board
56
Oriented strand board (osb)
Long strands of wood compressed and glued _ similar to plywood, brittle, can have resin coating for ext. Use.
57
Particle board
Smaller fibers than OSB - typically used under wood veneer or plastic laminate, not strong, not good wi moisture
58
32/16 rating wood
16" spacing for floor, 32" for rafters
59
Exterior wood rated
Better for exterior than exposure -1
60
Hardboard
High density fiberboard - can be used as exterior sheathing - Masonite
61
Insulating fiberboard sheathing
Law density fiberboard, can be used as ext. Sheathing typically coated in asphalt (water resistance) ) non-structural, has an r-value ( air pockets)
62
Hardwood plywood
Nicer looking - used for finewoodworking
63
Agrifiber panels
Agricultural waste products - wheat board, strawboard, riceboard- can be thick and structural
64
FSC
Forest stewardship council
Certifies wood that is grown using renewable practices
65
When is treated wood required?
Wood joists less than 18" above grade
Wood beams/girders are less than 12" above grade
Plates, sills sleepers are in direct contact with masonry or concrete that is in direct contact with earth
Wood framing members or sheathing are less than 8" from solo
66
Naturally decay resistant wood
Heartwood only
Black locust, Red mulberry, Osage orange, pacific yew
Slightly less - cypress, catalpa, cedar, chest nut, white oak, redwood, Blackwood
No decay under freshwater (saltwater is different)
67
Termite resistant naturally
Heartwood only
Eastern red cedar and redwood
68
Flathead nails
Common, sinker, box, roofing
69
Nails with tiny heads
Brad, finish, casing
Sink into wood, seal and paint
70
Nail gauge
Penny (d)
71
Nail connections
Face nail - strongest
Toe nail - angled, next
End nail - weakest
72
Nails are steel
Bright nails - no weather resistance
Hot-dipped galvanized - weather resistant
73
Word fasteners
Rafter anchor, just hanger, Beam hanger, Post base / post cap, gang nails
74
Platform framing
' Frame per level
75
Balloon framing
Tilt up /bypass floor - requires fire stopping
76
Wood corner framing
Overlap double top plates - ties walls together
77
Rimboard (Band jost)
Sits on top of header , below next floor - seals all just
78
Mild steel
Most steel members - i-beams, rebar, etc. - hot -rolled
79
Cold-rolled steel
(Formed) - stronger, cables, metal studs - extra strength and extra thin
80
Cast iron
Lots of carbon, strong, brittle
81
Wrought iron
Less carbon, weaker, malleable
82
Girder
A larger beam that supports smaller beams (perimeter)
83
How deep should a steel beam spanning 60' be?
1/20 *60 ft = 3ft
Beam depth is 1/20 the span
84
Beam depth
1/20 the span -depth
85
Girder depth
1/15 the span
86
Steel decking depth
1/40 the span
Decking and concrete: 1/24
87
Open web depth
1/20 the span
88
Stainless steel
Resistant to weathering - add nickel and chromium
89
Tempered steel
For greater strength or elasticity - hammers, springs etc
90
Castellated Beam
Use a wide flange, cut, lift, left, creates openings and extends length and strength
91
W12x45
12= nominal depth (inches)
45 = lbs/ft
92
Plate girder
Take a steel plate and customize or taper for the loads - match shape of beam to required forces
93
Bar lasts
Span between supports
94
Open web steel joist types
LH - long span - 96'
DLH - deep long span - 150'
K-most common/spans to 60'
95
Shear connection
Web is bolted, flanges not engaged Or vice verse
Bend is ok-lateral forces are not good
"Pin connection"
96
Moment connection
Web and flanges are engaged
Connection is so rigid forces to the beam cause columns to bend (bad in seismic)
Resists lateral forces better and passes bending from beam to column
97
Seated beam shear connection
Pin connection - web not engaged -flanges bolted and seated on angle
98
Stiffener plates
Use where added strength is needed at a connection
99
Dog bone cuts
Used for seismic, allows bend without breaking the joint
100
Eccentrically braced frames
Used in seismic zones, resists lateral forces without breaking
101
Shear wall
Rigid wall that keeps building from wanting to fall from lateral forces
102
What is a staggered truss system?
Every other floor is a truss supporting floor above and culling below - allows to be column free, minimizes floor to floor heights
103
Rigid core vs rigid perimeter
Rigid perimeter is more stiff
104
Cambering
Pre-curving a beam so when inflection it straightens and is more stable and wont bend / deflect down
105
Composite steel and concrete column
W-flange surrounded by concrete or tube filled with concrete - reduce steel in half - works for columns, not beams
106
Shear stud
Stud welded to metal floor pan to connect beams to concrete
107
Girt's
Metal Z channels that span between columns - usually holds panels, facades
108
Tag line
Ropes tied to steel used to Get it in the right place
109
Drift pin
Tapered steel pin used to hold steel in place to set bolts
110
Does steel burn?
No, just softens
111
Fabric used as enclosure
Polyester coated with PVC - low cost and low durability
Glass-fiber coated PTFE (Teflon) - DIA - medium cost and durability / good at keeping self clean
Glass - fiber coated with silicone - highest cost and durability
Long spans, luminescent
112
Pneumatic structures
Tennis bubble - air continuously pumped in - cost and energy intensive
113
Galvanic action
If surface is cathode and fastener is anode, it will react
Anode (most active)
Zinc
Aluminum
Steel
Iron
Stainless steel-active
Tin
Lead
Copper
Stainless steel-passive
Cathode (least active)
Provide insulator (rubber) to prevent reaction
114
Concrete
A composition of Portland cement, aggregate ( rocks and sand), and water- add other chemicals for certain uses
115
Portland cement _ type l
Normal concrete
116
Portland cement _ type IA
Normal, air entrained
Allows freeze I thaw - 5% air bubbles
117
Portland cement _ type 2
Moderate resistance to sulfates
Sulfates break down concrete
118
Portland cement _ Type 2A
Moderate resistance to sulfates and air entrained
119
Portland cement _ type 3
High early strength
120
Portland cement _ type 4
Low heat of hydration (dams)
121
Portland cement _ type 5
High resistance to sulfates
122
How big should aggregatebl?
Less than 3/4 the space between rebar and no larger than 1/3 thickness of slab
123
Pervious concrete
Aggregate all same size
124
Lightweight aggregate
Geological popcorn - expanded shale
125
Admixtures
Workability agents, air entraining, water reducing superplasticizers, accelerating retarding, shrinkage -reducing , corrosion inhibitors, freeze protection, extended set control, coloring
126
Self consolidating concrete
When rebar is crowded inform, you want crisp edges- more pourable, smaller Ag. - needs strong forms
127
Fly-ash concrete
Can reduce embodied energy 1/3
Uses ash from coal plants
128
Where do we place reinforcing bars?
Where the largest forces are
129
What is the diameter of *8 rebar?
1' - 8 /8 "
#6 = 6/8 or 3/4
130
Grade 60 rebar
Rating of 60K psi
131
Welded wire reinforcing (wwr)
The "mesh" typically in the bottom of slabs 2 "- 12" spacing- resists tension forces in 2 ways - comes rolled in a grid
132
How do you splice rebar?
Overlap 30 x the diameter and tie wire or reinforcing bar couplers
133
Stirrups
Resist moderate diagonal twisting forces of the beam
Slabs don't require stirrups because of their surface area
134
Shrinkage temperature steel
Used in slabs, wire/steel reinforcing, perpendicular - the steel helps control cracking as the slab shrinks
135
Bars vs ties
Bars - compression with concrete taking the rest - tensile strength, provide flexibility with lateral
Ties-smaller, resists outward buckling, concrete prevents inward
136
Concrete creep
Over time concrete gets squished downward
137
Pre-stress, pre-tensioned, post- tensioned concrete
Pre-stressed - squeezes concrete together
Pre-tension and post- tension are types of pre-stressed
Pulls cables or rods tight to push concrete together to make it stronger (gives camber)
Pre-tension-infactory
Post-tension - cast in place
138
If a concrete beam is one foot wide, how deep should it be?
3:1 ratio - 36"
139
One way slab
Cast as one continuous pour - column - primary, girder - primary, beam, - secondary, slab - tertiary
140
One way solid slab
Stab bands (as girders) short and stout wider
Reduces distance between beams, reduces floor to floor height, minimal structure to work around
4-10" deep
141
One-way joist system ( ribbed slab)
Column, beam, joist bands, distribution rib (distributes load between beams)
3-4,5" deep
142
Wide module slab
Thicker slab, half as many joists, slab can span further - wide beams
143
Two way solid stab
Two way are good for square bays
Cantilever 30% of slab around perimeter - reduces bending forces in middle and reduces columns
144
Two-way flat slab
No ribs, no beams - heavily loaded floors (factories) drop panel at column to reduce shear stress -thickened slab at drop panels
145
Two-way flat plate slab
More lightly loaded-multi- family , better floor to floor height, clearance for other trades, extra rebar at columns in lieu of drop panels
5-12" deep
146
Two-way just system (waffle slab)
Most expensive, longer spans between columns, heads at columns, use comes as formwork to create grid of joists
3-4,5" dep plus dome
147
One way stab vs 2 way
1 way is rectangular bays 2 way is square bays
148
Pre-cast concrete
Use type 3 early strength
Can cast new every 24 hours
Size to transport on truck
149
Masonry mortar
Type i-normal cement
type 2- moderate sulfate resistance
Type 3-high early strength
Structurally mortar is most important
Use Portland cement, not masonry cements
150
Portland cement mortar
Cement lime mortar - Portland cement, hydrated lime, aggregate, water
Blended hydraulic cements - Portland + slag / ads
151
Mortar types (by strength)
M a S o N w O r K
Type m- highest strength, belowgrade
Type s- exterior reinforced masonry (most common)
Type N- general use (most common)
Type o - low strength interior
Type k- not strong' or used anymore
152
Efflorescense
Staining of salts / minerals without proper drainage
153
Fly-ash
By product of coal boilers
154
Brick
Fire resistant, weather resistant, water resistant, low maintenance, small size - usually local
155
Clamp of bricks
The way bricks used to be stacked to be fired
156
Brick sizes
Modular, standard, king, utility, Norman, Roman
Hollow brick, solid brick, frogged brick, cored brick
157
Types of brick joints
Flush joint, raked joint, stripped joint, concave joint, vee joint weathered joint, struck joint
Vee and concave - use if rainy or freezes
158
Low lift vs high lift grouting - reinforcing
Low lift - pour 4' at a time, partially cure, then continue
High lift - taller structural well and bricks are omitted to ensure grout gets where it needs to
159
Appearance grade of brick
FBA facing brick (anomaly) -more variation in size and chippage
FBS - standard- some variation
FBX _ exacting - more uniform
160
Brick grade
Sw- (snow brick) ' hardest- underground - any climate
Mw - (Miami /moderate) - weather resistant
NW (interior)
161
Brick walls start in the middle or at the corners
Corners
162
Types of arches
Segmental, elliptical, parabolic, jack, Tudor, Roman ) gothic
163
Granite
Most common - igneous (volcanic) hardest, non porous, most permanent, fine-medium-course grade, can be 3/8" thick +
164
Limestone
Sedimentary, porous and weakest, can be polished (classified as marble but not), contains quarry sap - needs today- select (finest grain) → variegated (coarsest / flaws), can deteriorate in acid
165
Quartz
Sedimentary - includes sandstone, brownstone, bluestone - porous - no polish
166
Slate
Metamorphic, comes from clay , has planes of cleavage (from clay), good for paving, shingles, cladding
167
Marble
Metamorphic, comes from limestone ( recrystallized) I easily carved and polished, can be cut as thin as 3/4", graded from A (uniform) to D (faults) but often most unique and interesting, deteriorates in acid
168
Stone
Higher moisture = weaker
169
Modulus of rupture
Likelihood stone will accept metal anchors
170
Stone types
Field - found infield
Rubble - irregular quarried with 1 + usable face
Dimensional - cut stone, slabs, ashtar-smaller units
Flagstone - irregular shapes _ good for floors
171
Stone masonry vs cladding
Masonry - stacked with mortar like brick-may stain
Cladding-attaches as skin with anchors larger scale, more precise
172
For best strength and weather resistance, stone is laud with grain going -
Horizontally
173
Typical cmu size
8x8x16
174
Dry stacked masonry
(Surface bonded) stacked with no mortar then covered with tuck layer on both sides -like stucco
175
Vapor barriers / retarders
Class I _ less than 0,1 perms
Class 2- 0.1 → 1.0 perms (some plywood, latex paint, kraft paper, rigid foam ins)
Class 3- 1.0 → 10.0 perms (gyp wall w/ latex paint)
176
Vapor barrier placeineert
Warm side of wall
177
Notching in wood beams
Hole can be anywhere as long as diameter is less than 1/3 D
178
Notching in stud wall
Max diameter is 40%, of stud depth, cannot exceed 25% of stud depth, max diameter is 60% it there's a double stud - cannot have a hole and notch in same cross section
