exterior walls (wood)
DESCRIPTION
Exterior Walls (Wood). Framing Techniques in Light Frame Construction. General Terms & Methodology Platform Framing Balloon Framing Post & Beam. Wind. Forces on Exterior Wall Construction. Wall had their own dead load Walls support vertical loads (LL + DL) from roof ceiling floors - PowerPoint PPT PresentationTRANSCRIPT
Exterior Walls (Wood)
Framing Techniques in Light Frame Construction
General Terms & Methodology Platform Framing Balloon Framing Post & Beam
Forces on Exterior Wall Construction
Wall had their own dead load Walls support vertical loads (LL + DL) from
– roof– ceiling– floors
Must also resist lateral forces due to
Wind--Horizontal/Lateral Load
Wind causes both horizontal & vertical movement with vertical forces called uplift– Use of wind speed
map to determine wind speed (70 to 110 miles per hour)
Palm tree pierced by plywood missile, Hurricane Andrew
Wind Forces
Horizontal forces are treated like seismic
Vertical forces are called uplift– Wind blowing across the
structure creates a negative pressure (sucking force)
– Wind blowing thru an opening increases inside pressure (lifting force)
Suckingforce
Liftingforce
Earthquakes
Shock waves cause lateral and vertical motion in a building
Usual design, for vertical forces, will take care of the vertical seismic forces
Major factors effecting seismic forces:
– The type of structure (material its made of)
– Nature of soil under the building Building are not designed to be earthquake-proof, but
to be earthquake resistant
Exposed Earthquake Module
Connections called “ductile” are designed to give the building the ability to move, bend or stretch without snap and breaking apart during earthquakes
Typical Wall Construction
One and two story framing– 2” x 4” @ 16” O.C.– Occasionally 2” x 6” @ 24” O.C.
Three story framing(load bearing walls)– lower floor = 2” x 6” @ 16” O.C.– other floors = 2” x 4” @ 16” O.C.
Window Framing Terms
Header– supports structure above
windows
Header Jack– supports header
Cripple Studs Double Plate Rough Sill Trimmer
– additional stud to trim out window
Double Plate
Cripple Studs
Header
Header
Jack
Cripple Studs
Rough Sill
Trimmer
PlatformFraming
Foundation
Sill (Mud Sill)
Floor Joist
Girder
Subfloor isPlatform
DoublePlate
Blocking
Sway Bracing
(cornerbracing)
Rafter or Truss
Also called
Western
Framing
Sheathing
Ledger
BalloonFraming
Studs extend
from sill to
roof line (full length)
Also called
Eastern Framing
Terms similar to Platform Framing
Balloon Framing
Used primarily for 2 story construction Less chance of shrinkage or movement
– recommended for masonry veneer & stucco 2nd floor supported by wall with
– let-in 1x4 called a ribbon Less overall material Longer members usually more costly Firestop blocking required
Balloon Framing Terms
Ribbon Firestop
Framing Construction at Corners 3 full studs
– good with super insulated buildings
3 full studs and blocking
3 full studs and 1/2” shim
Post & Beam
Relatively new
and less
common in residential
construction
Used in heavy
timber const
for years
Beam and Posttypically 4’-8’ OC
beam
post
T&G planks2x6 or 2x8
Tongue & Groove Planking Used for Roof or Floor when structure is space 24” or more O.C.
Shear Wall Design
Resistance to lateral forces resulting from earthquakes or wind
Connections:– 1 sheathing to joist– 2 joist to top wall– 3 edge nailing– 4 tie-down straps– 5 anchor/shear bolts
Detailing areas of Shear Walls
Diaphragm transfer
Exterior Finishes
Siding– Wood Siding– Metal Siding
» Steel» Aluminum
– Vinyl Siding Stucco Exterior Finish System--a nylon mesh & plaster
over insulation board
Wood Siding
Various sizes and Shapes– Solid wood– T1-11
(plywood)» 4’x8’ sheets
– Masonnite Lap board
» 8-12” x 16’
Steel & Vinyl Siding Higher in Cost Lower in Maintenance
– no painting Long lasting Concerns when using this siding
– expansion– denting– cracking– rusting
Cement Stucco
Least expensive
building paper
wire fabric lath
furring nails
drip screed
sheathing vs. open frame
3 coats of plaster
brownfinish
scratch} 7/8”
Interior Finishes
Plaster & Lath Wood Paneling Dry wall
Plaster & Lath
Old technique - not in common use today– 3/8” - 1/2” thick lath– 1/2” coat plaster– uses a ground board at edges
Wood Paneling
4’ x 8’ sheet panels vertical/horizontal/angle pieces solid boards wide range of wood types and colors
Drywall
Commonly called sheet rock, gypsum board (GB), or plaster board
typically 1/2” on wall, 5/8” on ceiling Nail directly to studs, nails commonly 8”
OC Tape - 3 coats/ texture Green/blue board or cement board for
bathrooms
Assignment Sheet A-4 Dimension the enlarged entry plan Add restrooms to match A-1 & A-2 Reference door and window (A-1 & A-2) Hatch or poche’ as needed Using elevation 1/A-4 create elevations for
A/A-4 and B/A-4
Drawing Assignment Wall Section
5/8”dia x 12”AB @ 32” 8” Min from backfill to top FDN 4” concrete slab w/ 6x6 10/10 wwf
or wwm (wire welded fabric or mess)
Blocking 6-8”compact fill 95% density foundation wall 8” with normal
footing size (w x 2w) 30” frost depth
Foundation insulation
Drawing Assignment Wall Section Cont.
2”x4” wood studs Treated wood plate Found. (2) #5 bars top and bottom
and (1) #5 @ 18” o.c. vertical 12”x18” cont. conc. footing w/ (2)
#4 bars x cont. #4 ties @ 18” o.c. (50% 2’-6” &
50% 1’-6”) T&G plywood subfloor (second
level)
Wall Section Drawing Cont. Slope 3:12 5/8” GB inside wall Beam bearing @ 8’-0” Roof beam 3x10 3/4” CDX plywood sheathing 3/4” T1-11 siding (brick,
stucco, etc.) Overhang 18” 2x2 starter board 1-1/2” from
edge