Five-story Building in the Pacific NW
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This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.
Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.
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© The Wood Products Council 2012
Learning ObjectivesAt the end of this program, participants will be able to:At the end of this program, participants will be able to:
1. Recognize requirements of the Portland, Seattle, and Washington State Building Codes that allow 5-story, Type VA construction.
2. Identify framing and detailing solutions for mitigating shrinkage effects and related details at interface between wood and other building materials such as brick veneer steel concrete and masonryas brick veneer, steel, concrete, and masonry.
3. Recognize solutions that wood can provide as an energy efficient framing solution.
4. Recognize requirements to provide sustainable “green” roof systems and demands this can place on the vertical and lateral structural system and wood solutions to meet these demands.wood solutions to meet these demands.
MID-RISE WEBPAGE
http://www.woodworks.org/woodBenefits/mid-rise-construction.aspx
MID-RISE WEBPAGE
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FIVE-STORY WOOD BUILDINGS IN THE PACIFIC NWPACIFIC NWJONATHAN SIU, PE, SE
(PRINCIPAL ENGINEER/BUILDING OFFICIAL, CITY OF SEATTLE)
JEFF REIBMANN, AIA, LEED® AP(SENIOR ASSOCIATE, WEBER THOMPSON)
CHARLES GRIFFES, JR., PE, SE, , ,(PRINCIPAL, CT ENGINEERING)
PLAYING BY THE PLAYING BY THE RULES (2009)( )
JON SIU, PE, SECity of Seattle, Department of Planning and Development
BASIC CODE ALLOWANCEIBC TABLE 503
TYPE OF CONSTRUCTION
TYPE III TYPE V
A B A
HEIGHT (feet) 65 55 50HEIGHT (feet) 65 55 50
GROUP STORIES (S)AREA (A)
R 1 S 4 4 3R-1 SA
424,000
416,000
312,000
R-2 S 4 4 3R-2A 24,000 16,000 12,000
R-3 SA
4UL
4UL
3ULA UL UL UL
BASIC SPRINKLER BONUSIBC SECTION 504.2
One extra story plus 20’ of height allowed, provided NFPA 13 sprinkler system throughoutAll R occupancies required to be p qsprinklered => automatic increase from 3 to 4 stories and 50’ to 70’
SEATTLE AMENDMENT SBC TABLE 503
TYPE OF CONSTRUCTION
TYPE III TYPE V
A B A
HEIGHT (feet) 65 55 50HEIGHT (feet) 65 55 50
GROUP STORIES (S)AREA (A)
R 1 S 4 4 ((3)) 4R-1 SA
424,000
416,000
((3)) 412,000
R-2 S 4 4 ((3)) 4R-2A 24,000 16,000 12,000
R-3 SA
4UL
4UL
((3)) 4ULA UL UL UL
WA STATE AMENDMENTWSBC SECTION 504.3 (ADDED)
One extra story allowed (in addition toOne extra story allowed (in addition to sprinkler bonus), provided:• Group R-1 and R-2 occupanciesGroup R 1 and R 2 occupancies • Type VA construction
NFPA 13 i kl t th h t• NFPA 13 sprinkler system throughout• Interior exit stairways and ramps are
i d i d i h S ipressurized in accordance with Sections 909.20 (smokeproof stair) and 909.11 (standby power)(standby power).
PORTLAND ALTERNATIVEIBC TABLE 503
TYPE OF CONSTRUCTION
TYPE III TYPE V
A B A
HEIGHT (feet) 65 55 50HEIGHT (feet) 65 55 50
GROUP STORIES (S)AREA (A)
R 1 S 4 4 3R-1 SA
424,000
416,000
312,000
R-2 S 4 4 3R-2A 24,000* 16,000* 12,000
R-3 SA
4UL
4UL
3ULA UL UL UL
* Reduced for special 5-story wood-frame
PORTLAND ALTERNATIVE
M b t d f R 2 ( t
ADMINISTRATIVE APPEAL (DRAFT)
• May be granted for R-2 occ (not guaranteed)
2• Table 503 area reduced to 12,000 ft2
• Max 75’ to parapet from FD access + 1 facade meets FD aerial access req’mts
• Exterior walls rated for exposure from pboth sides—fire-retardant treated wood not req’dq
• Other provisions….
PORTLAND & SEATTLE
Special inspection for seismic resistance
CH.17 – INSPECTION & OBSERVATION
• Special inspection for seismic resistance req’d (IBC/SBC 1707.3)
• Structural observation req’d (SBC 1710 2• Structural observation req d (SBC 1710.2, Portland 24.95.080)
SMOKEPROOF STAIR (WA)( )IBC/WSBC SECTION 909.20
• Naturally orNaturally or mechanically ventilated vestibule
• Activated by local smoke detectorssmoke detectors
• Other details….
PRESSURIZATION ALT (WA)( )IBC/WSBC SECTION 909.20.5
0 10” 0 35” t• 0.10” – 0.35” water column relative to buildingbuilding
• Activated by local k d t tsmoke detectors
• Other details….
STAIR PRESSURIZATION (SEA) ( )SBC SECTION 909.21
For low-rise buildings:For low rise buildings:
• Min. 0.15” water column relative to buildingg
• No specified max –meet Ch 10 door opening force
• Activated by fire alarm anywhere in building
• Other details….
PODIUM BUILDINGS (WA & PORTLAND)PORTLAND)IBC/WSBC SECTION 509.2
• Separate buildings for area, # of stories—overall height not increasedg
• Type IIIA, IIIB, VA above, Type IA below (1 story) 3-hour separation between(1 story), 3 hour separation between
• 2-hour rated shafts penetrating 3-hour separationseparation
• Limitations on occupancies above and below 3-hour separation (no R below)
PODIUM BUILDINGS (SEA)( )SBC SECTION 509.2
Si il t IBC/WSBC i i tSimilar to IBC/WSBC provisions except:• Specifically permits wood stairs in exit
enclosures penetrating 3-hour separation• Allows same occupancies above and
below 3-hour separation• Roof decks >10 occupants or occupied
floors not allowed more than 75’ above lowest fire access
AND
PODIUM BUILDINGS (SEA)( )SBC SECTION 509.2
2 stories above grade plane allowed below 3-hour separation provided:• Max. 7 stories above grade plane• NFPA 13 sprinklers above & below 3-hourNFPA 13 sprinklers above & below 3 hour
separation• Exit enclosures to be pressurized per• Exit enclosures to be pressurized per
SBC 909.21k “5 2”• a.k.a “5 over 2”
FIRE WALLSIBC/WSBC/SBC SECTION 706
• Separate buildings for area • Needed for large developmentsg p
• Max. area ≈ 108,000 ft 2(Type VA R-2 occupancy)(Type VA, R-2 occupancy)
FIRE WALLS – ISSUESIBC/WSBC SECTION 706.2Structural independence vsDiaphragm continuityy
SAW CUT OR NOT?
FIRE WALLS - ISSUESIBC/WSBC/SBC SECTION 1025.1
Number of stairs vs Horizontal exitsNumber of stairs vs Horizontal exits
Fire Wall (typ.)
Corridor
Horizontal Exit?Exit?
Required Stair?
ARCHITECT’S ARCHITECT’S PERSPECTIVE
JEFF REIBMAN, AIA, LEED APWeber Thompson
Solara, 2008 Pine + Belmont, 2011
West Seattle Junction, 2012 Mercer View Apartments, 2007Axis, 2010 Sunset Electric, 2012
2-hr wall
3-hr wall
Staggered 3-hour separation stepping with grade
•5 stories Type V over 2 stories Type 1 + 1 Basement •Reuse of a Historic Façade•Courtyard for daylight, circulation, and cooling•Meets 2030 Challenge w/ 40% energy reduction•Metal Clad exterior over Wood Frame Construction
Historic brick façade
3-hr. separations
Sunset Electric Building – Seattle Sunset Electric Building – Seattle
7/17/08 Fire retardant wood7/17/08 Fire retardant wood infill begins to appear in the Type 1 Construction
Infill Framing at Type I construction with Fire Retardant Wood and Light Gauge Steel top trackGauge Steel top track
Large Air Handling Unit atop the Aljoya Project. Equipment Loads
6/16/09 - Approaching Occupancy6/16/09 Approaching Occupancy
The Completed Project
ENGINEER’S ENGINEER’S PERSPECTIVEPERSPECTIVE
CHARLIE GRIFFES, SE
CT ENGINEERING
Capitol Hill, Seattle
THE BRAEBURNALLEGRO
University District, Seattle
APARTMENTS
CHIN ALOHA
Queen Anne Hill,
APARTMENTS
Seattle SCHEMATICSCHEMATICDESIGNDESIGN
SCHEMATIC DESIGN SE INPUT
•Stacking unitsStacking units•Minimizing dead load, but get real values before lateral load designvalues before lateral load design•Avoid hard spotsG d di t ib ti d l th f h•Good distribution and length for shear
walls
LATERAL LOAD LATERAL LOAD DESIGNDESIGN
LATERAL LOAD DESIGN• Holdowns are the big deal.Holdowns are the big deal.• MBR System – early 90’s.
C ti d t t i l• Continuous rod system typical for 4 and 5 story wood frame structuresstructures.
TWO STAGE ANALYSIS• Concrete base structure – wood above.Concrete base structure wood above.• Stiffness of Concrete Base to be 10x of
wood.wood.• Period of entire structure less than 1.1x of
upper (wood)upper (wood)• We assume to be all true (unless asked!)
SHEARWALLSELECTION
•Use full height long walls•Use full height, long walls •Avoid plumbing walls•Short exterior walls present challenges
LOAD DISTRIBUTION TO SHEAR WALLS
Fle ible or Rigid Diaphragms?• Flexible or Rigid Diaphragms?• 3-Sided box – 25’ max open side?• Tributary Area Method• Lump into light, medium, heavy wall p g , , y
types
HOLDOWN DESIGNC m lati e forces (OT forces from alls• Cumulative forces (OT forces from walls above included in walls below)D d L d t d• Dead Load to reduce. Be as generous as you can
f f• Max HD force of 25k or so. Get more walls or adjust SW distribution
HOLDOWN SPECEOR to specif loads or rod si e• EOR to specify loads or rod size
• EOR to detail anchorage to concrete per ACI 318 A di DACI 318 - Appendix D.
• Be sure to detail corner and edge anchor conditions.
• EOR to call for shrinkage compensation (or not?) and specify how much per floor (1/4”, 3/8”?)
SHRINKAGESHRINKAGE – THE GRAND
• 4 Story Steel• 4 Story Steel Frame
• Wood• Wood shrinkageR k d• Racked windowsL it• Lawsuit
ROD SYSTEM COMPONENTS
Shrinkage Fastener (typical)Bridge header support at top level
B id T i E h SidBridge Trimmers Each SideBearing Plate – color coded (typical)
Joist Blocking (transfers compression)Joist Blocking (transfers compression)
Compression Members for downloadThreaded Rod (typical)
Standard Rod Coupler (typical)
( yp )
A h B ltRod System Anchor (cast in place shown)
Anchor Bolt
SHRINKAGE EFFECTSWithout shrinkageWithout shrinkage compensation, wood shrinkage will lead to looseness in holdown system.
EARTHBOUND SLACKJACK®
SHRINKAGE DEVICESHRINKAGE DEVICEExpansion Type Device that axially moves with building.Fully color coded for inspectionFully color coded for inspection.Available up to 3 inch travel for six story applications.
SIMPSON CTUD COUPLING DEVICE
SHRINKAGE - HOW MUCH?1/4” to 3/8” per floor T pical Seattle area• 1/4” to 3/8” per floor. Typical Seattle area projectA KD f d TJI t fl• Assumes KD spec for wood, TJI type floor framing, platform framing.
O f• EOR specifies that shrinkage compensation is required and how much is to be accommodatedaccommodated.
“CONSOLIDATION”Looseness in str ct re d e to small gaps• Looseness in structure due to small gaps , not square cuts, warped membersSt t lid t ith li ti f• Structure consolidates with application of dead load
/ ff• Adds 1/8” or so to shrinkage effect• Apply dead load before applying sensitive
finishes
HARD SPOTS
• Steel FramesCMU or concrete• CMU or concrete shearwallsN h i k t• Non-shrink post and beam stacks
RESPONSE TO HARD SPOTS1 Comm nicate ith o ner contractor and1. Communicate with owner, contractor and
architect.2 C t l th i t t t f th d2. Control the moisture content of the wood.
Specify and measure.f3. Floor framing perpendicular to hard spot.
4. Apply Dead Load ASAP.5. Recognize problems early and respond with
fix.
OTHER SRUCTURALCHALLENGESCHALLENGES
COMPRESSION MEMBERSTotal bundled studs required match structuralTotal bundled studs required match structural plans or rod system shop drawings
DRIFT CALCSMa be req ired b b ilding official• May be required by building official
• Not much can be done structurally to alter d i d d d iftdesign and reduce drift
• Shrinkage compensation devices• Rod sizes
DRAG STRUTS OR COLLECTORS
• Get load to heavily yloaded SW’s
• Inside corners
IRREGULARITESNon stacking shear alls ( ertical or• Non-stacking shear walls (vertical or horizontal irregularity)R t t ( l i l it )• Re-entrant corners (plan irregularity)
• Penalty - Increased loads at connections
MASONRY VENEER• Will not shrink with the wood unless gapped at floors• Will not shrink with the wood unless gapped at floors• Multiple stories should be considered a “hard spot”• Support ledgers at each floor an option, with joint to allow pp g p , j
for shrinkage
VERTICAL LOAD DESIGNSt d capacit t picall based on• Stud capacity typically based on crushing of plates.P ibl D Fi l t ith H• Possibly use Doug Fir plates with Hem Fir studs. Whole floor at a time.
• Post loads may have bearing issues.
QUESTIONS?This concludes The American
Institute of Architects Continuing Education Systems Course
Jon Siu ([email protected])
Jeff Reibman ([email protected])(j @ p )
Charlie Griffes([email protected])
Wood Products Council 866.966.3448 [email protected]