VSEC Seminar March 26, 27 2008 Virginia Beach, VA Richmond, VA David DeSutter, P.E.

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts

EFCO UNIVERSITY 2008

VSEC SeminarMarch 26, 27 2008

Virginia Beach, VA

Richmond, VA

David DeSutter, P.E.

Director of Engineering and Customer Service

EFCO Corporation

Mitch Snead

The Snead Company

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Virginia Beach, VA

Richmond, VA

Better Communication = Better Overall Structure

Pondering Point:

During a “design event,” the typical commercial “window” will fail due to either improper anchorage or under-designed surrounding

conditions.

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



•Curtain Wall vs. Storefront (General, Construction, Connection and Anchors)

•Curtain Wall Performance – Wind, Snow, Seismic, Thermal, Impact, Blast

•CW/SF Manufacturer’s Design Considerations (What We Need)

•CW/SF Manufacturer’s Design Considerations (What We Get)

•CW/SF Manufacturer’s Design Considerations (What We Assume)

•CW Analysis, Rules of Thumb

•Reference Information

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Curtain Wall vs. Storefront - General

Available in three basic variations (“plane of glass”):

•outside set, •center set (a.k.a..flush glaze), •and inside set.

Storefront

OUTSIDE SET(S945)

CENTER SET(S403)

INSIDE SET(S433)

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Most Storefront is available in three (3) configurations (“glazing method”):

Outside glazed Inside glazed Vertical SSG glazed


Storefront

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Most Storefront is available in two (2) types of connections (“installation method”):


Storefront

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Most Storefront is available in limited widths and depths:

• 2” – 3” in width• 4” – 6 ½” in depth


Storefront

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Curtain Wall

Primarily available in one basic variation (“plane of glass”):

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Curtain Wall

Primarily available in three (3) basic configurations (“glazing method”):

Outside glazed Inside glazed Structurally glazed

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Curtain Wall

Primarily available in two (3) basic connections (“installation method”):

Shear Block Screw Spline “Unitized”

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Curtain Wall

Options, Options, Options

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Water Performance

System Water Control

Curtain Wall “Zone Pressure Equalized”

Storefront Diverting Water through entire system

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Water Performance – Curtain Wall

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Water Performance – Storefront

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Curtain Wall Anchors – Head & Sill

Anchor Bolts Control!

Direct Load Path to MWFRS

RwlMovement Allowances

Unlimited (?)

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Anchor Bolts Control!

Curtain Wall Anchors – Head & Sill

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Curtain Wall Anchors – Intermediate/Slabs

Rwl

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Curtain Wall Anchors – Intermediate/Slabs

Rwl

“Wind Load” Anchor = Roller Support

“Dead Load” Anchor = Pin Support

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Connections Control!

Storefront Anchors – Head, Sill & Jambs

Indirect Load Path to MWFRS

Rwl

Limited Movement

(1/8” max)

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts










Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Curtain Wall Performance

Wind, Snow, Seismic/Drift, Thermal/VM, Impact and Blast

Wind Considerations

•“Components and Cladding” provisions of ASCE 7 or Appropriate Building Code

•Corner Zones are Important! $

•Industry Standard Deflection Limits: L/175 (span <13’ – 6”), L/240 + ¼” (span >= 13’ – 6”)

•Accurate span information (dimensions), location of appropriate anchors! $$$$

•Aluminum Association ASD/LRFD

Goal: Transfer all wind forces to MWFRS

WL Reactions: 200 lbf to 3,500 lbf per anchor is typical

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




Snow Considerations

•Flat Roof Snow Loads + Drift Surcharge on Bladed Sunshades is (?)

•Mullion Attachment Typical for Sunshades

Goal: Transfer all snow forces to curtain wall system, then to MWFRS

Effect of Snow on Reactions: Little effect to MWFRS

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




Seismic Considerations

•Racking of CW – Engineer of Record Must Provide Calculated Interstory Drift!

•Controlled “Fallout” is the Standard (Fallout in ASCE 7)

Ps

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts





•Shear Forces per ASCE 7

• Calculate Fp = .4ap(Sds)Wp/(Rp/Ip) (1+2(z/h))

• Fp= Seismic force acting at centroid of mullion, with load evenly distributed along length of mullion

– Fp acts the same as the wind load

– Varies for perimeter anchors

– Determine Deflection, Stress of frame member

– Can be problematic for intermediate

wind load anchors

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts





•Racking of CW

•Shear Forces per ASCE 7

Goal: Transfer all seismic forces to MWFRS

Seismic Reactions: Usually 50% of WL (200 lbf to 3,500 lbf per anchor is typical), but in-plane along weak axis

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




Thermal/Vertical Movement Considerations

•CW Mullions Buckle Easily

•Must Account for all Vertical Movement (Thermal + Building Movement) $$$$

•Must Maintain Integrity of Perimeter Sealant Joint and Satisify Architectural Aesthetics

•Sealant Joint RoT = ½ x Joint Width (Compression/Tension)

•“Standard” System (no “Bells & Whistles”) good for +/- ¼” to ½” +/-!!

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts





Total VM = Thermal + LL + CS + Creep + DL

Thermal

Glass contact controls

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




Thermal/Vertical Movement Considerations3 3 33333333

33

33

33

2 2

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts





HL94

STV2STV2STV2

STK4 STK4

WN

E0

WN

E0

WE

EP

WN

E0

WV80STC0

5959

6345

S

ARCH./G.C. NOTE:COPING AT THIS LOCATION WILL SEE POSSIBLE3/4" OF MOVEMENT DUE TO THE THERMALEXPANSION OF VERTICAL MULLION. PLEASECONFIRM AS ACCEPTABLE.

Thermal + Slab Movement

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts





Goal: Avoid all thermal forces to MWFRS

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Curtain Wall PerformanceWind, Snow, Seismic/Drift, Thermal/VM, Impact

and Blast

Impact Considerations

•Large Missile <30’ (ASTM E1996 and 1886)

•Small Missile >30’ (ASTM E1996/1886)

•Large Missile Dependant on Wind Speed!

•Identify Windborne Debris Region

1. Areas within one mile of the coastal mean high water line where the basic wind speed is equal to or greater than 110 mph and Hawaii

2. Areas where the basic wind speed is equal to or greater than 120 mph

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Curtain Wall PerformanceWind, Snow, Seismic/Drift, Thermal/VM, Impact

and Blast

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Part D. Missile GuidelinesLarge and Small Missile Impact per ASTM E 1996 - 06


ASTM E 1996 - 06

Missile Level Missile Impact Speed

A (10) 2 gram steel balls 130 f/s (39.62 m/s)

B 2 lb. 2 x 4 (1’-9”)lumber 50 f/s (15.25 m/s)

C 4.5 lb 2 x 4 (4’) lumber 40 f/s (12.19 m/s)

D 9 lb 2 x 4” (8’) lumber 50 f/s (15.25 m/s)

E 9 lb. 2 x 4 (8’) lumber 80 f/s (24.38 m/s)

Manufacturer

Of

Architectural

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Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




ASTM E 1996 - 06



B 2 lb. 2 x 4 (1’-9”)lumber 50 f/s (15.25 m/s)

C 4.5 lb 2 x 4 (4’) lumber 40 f/s (12.19 m/s)

D 9 lb 2 x 4” (8’) lumber 50 f/s (15.25 m/s)

E 9 lb. 2 x 4 (8’) lumber 80 f/s (24.38 m/s)

Many projects will require level “C” or below

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




ASTM E 1996 - 06



B 2 lb. 2 x 4 (1’-9”)lumber 50 f/s (15.25 m/s)

C 4.5 lb 2 x 4 (4’) lumber 40 f/s (12.19 m/s)

D 9 lb 2 x 4” (8’) lumber 50 f/s (15.25 m/s)

E 9 lb. 2 x 4 (8’) lumber 80 f/s (24.38 m/s)

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




ASTM E 1996 - 06

Assembly Height Enhanced ProtectionBasic Protection

Wind Zone 1 C A D D

Wind Zone 2 C A D D

Wind Zone 3 D A E D

Wind Zone 4 D A E D

< 30 ft > 30 ft < 30 ft > 30 ft

110 < Wind < 120

Basic Wind Speed (MPH)

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Part E. ASTM vs. Florida Building Code

Large and Small Missile Impact per FBC/TAS 201 & 203


Pass/Fail per FBC and/or Dade/Broward Counties, Florida The specimen shall resist the impact and cyclic loading with no tear formed longer

than 5” and 1/16” in width through which air can pass.

All specimens have to be tested at the Florida Approved Lab.

TAS can NOT be tested at EFCO

If any specimen fails to meet the requirements, the set of specimens is rejected. A retest of all (3) specimens is permitted.

Cyclic Loading Identical to

ASTM E 1886

Small Missile Impact

Large Missile Impact

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




Goal: Prevent Loss of Glass Bite

Reactions: Little to no effect to MWFRS due to impact


•Large Missile <30’ (ASTM E1996 and 1886)

•Small Missile >30’ (ASTM E1996/1886)

•Large Missile Dependant on Wind Speed!

•Identify Windborne Debris Region

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




Blast Considerations

•Method 1: DoD UFC 04-010-01 = Prescriptive for “Low” or “Very Low” Level of Protection

•Method 2: Design for Specific Blast Load and Specific Level of Protection

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts





Goal: Transfer Blast Loads to MWFRS

Reactions: Up to 20,000 lbf per anchor (extremely short duration)!

Wood, stud and masonry construction should be avoided for multi-lite or multi-span CW

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts










Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Curtain Wall PerformanceWhat We (Manufacturers) Need

Wind Considerations

1. Appropriate Code

2. Appropriate Exposure and Wind Speed

3. Accurate Span Information!

4. Appropriate Perimeter Condition (Structure) for “Higher” DP Regions

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



V V

T

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Snow Considerations

1. Appropriate Code

2. Appropriate Ground Snow Load and Drift Surcharge

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Seismic/Drift Considerations

1. Appropriate Code

2. Must, Must, Must have calculated interstory drift!

3. Must have Sds (Design Spectral Response Acceleration, ASCE 7, Section 9.4.1.2) to calculate seismic shear.

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Thermal/VM Considerations

1. Total Vertical Deflection per Floor

2. Is the Total Vertical Deflection “Up and Down” or Different?

3. (The CW Manufacturer Will Add in the Thermal Movements)

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




1. Appropriate Code (for DP)

2. Appropriate Wind Speed (Local Codes May Override Model BC)

3. Appropriate Perimeter Condition (Structure) for “Higher” DP Regions

4. Identify Windborne Debris Regions

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




1. Charge and Standoff Distance or Blast Load and Impulse for “Blast Design” (DoD is prescriptive)

2. Appropriate Perimeter Condition (Structure) for Short Duration Blast Loads!

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




10K – 20K

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts










Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Curtain Wall PerformanceWhat We (Manufacturers) Get

Wind Considerations

1. Appropriate Code [No code or conflicting wind speeds – ie. 3 second gust wind speeds with fastest mile code]

2. Appropriate Exposure and Wind Speed [Conflicting wind speeds]

3. Accurate Span Information [“Like pulling teeth”]

4. Appropriate Perimeter Condition (Structure) for “Higher” DP Regions [You be the judge - Plywood, 20 ga. Stud, face brick, masonry/concrete w/o edge distance are problematic]

Manufacturers Bid Documents:

1. Take-off from installer

2. Plans (Architecturals, limited Structurals) and Specs

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Wind Considerations

3. Appropriate Perimeter Condition (Structure) for “Higher” DP Regions [Is this lintel able to handle the wind loads?.]

200# - 3,500#

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Wind Considerations

3. Appropriate Perimeter Condition (Structure) for “Higher” DP Regions [Can this masonry handle these loads? If so, it is very difficult for the CW anchor to hit the center of the cell.]

200# - 3,500#

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Wind Considerations

3. Appropriate Perimeter Condition (Structure) for “Higher” DP Regions [No doubt the concrete can handle the wind loads, but maintaining edge distance is impossible w/o customization.]

200# - 3,500#

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Snow Considerations

1. Appropriate Code [Code is identified 50% of time.]

2. Appropriate Ground Snow Load [Ground snow load is specified in some cases, drift surcharge is rarely, if ever specified…]

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




1. Appropriate Code [Typical spec: “Curtain wall system must be designed to resist appropriate seismic forces and displacements…..”]

2. Must, Must, Must have calculated interstory drift. [See above.]

3. Must have Design Spectral Response Acceleration (Sds) variable to calculate seismic shear (ASCE 7, Section 9.4.1.2) [This is rarely, if ever provided in specifications]

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




1. Total Vertical Deflection per Floor (not the Allowable by Code!) [Sometimes we get the LL, column shortening and creep as a maximum for all floors, all spans. Most of the time, spec reads: “…curtain wall system must be designed to accommodate deflections including, but not limited to live load, dead load, column shortening, creep and thermal expansion and contraction of the curtain wall system assuming a temperature differential of 180 deg F…”]

2. Is the Total Vertical Deflection “Up and Down” or Different? [Rarely get different values for “up” and “down,” see above]

3. (The CW Manufacturer Will Add in the Thermal Movements)

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




1. Appropriate Code (for DP) [No code or conflicting wind speeds – ie. 3 second gust wind speeds with fastest mile code]

2. Appropriate Wind Speed (Local Codes May Override Model BC) [Conflicting wind speeds]

3. Appropriate Perimeter Condition (Structure) for “Higher” DP Regions [You be the judge…]

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




1. Charge and Standoff Distance or Blast Load and Impulse for “Blast Design” (DoD is prescriptive) [Rarely if ever specified…]

2. Appropriate Perimeter Condition (Structure) for Short Duration Blast Loads! [Our opinion is the perimeter structure is generally ignored for windows and CW for blast projects …]

10,000# +

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Curtain Wall PerformanceWhat We (Manufacturers) Assume

Wind Considerations

1. Appropriate Code [No code or conflicting wind speeds – ie. 3 second gust wind speeds with fastest mile code] [Assume latest ASCE 7.]

2. Appropriate Exposure and Wind Speed [Conflicting wind speeds] [Assume an Exposure Cat. (usually “C”) and wind speed based on map.]

3. Accurate Span Information [“Like pulling teeth”] [“Quote and qualify” then hope for the best and plan for the worst]

4. Appropriate Perimeter Condition (Structure) for “Higher” DP Regions [You be the judge - Plywood, 20 ga. Stud, face brick, masonry/concrete w/o edge distance are problematic] [Assume that condition will support loads, assume architect passes info to engineer of record.]

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Wind Considerations

3. Appropriate Perimeter Condition (Structure) for “Higher” DP Regions [Plywood, 20 ga. Stud, face brick, masonry/concrete w/o edge distance and lintels.] [Assume that condition will support loads, address water concern, redesign anchor as necessary, assume architect passes info to engineer of record.]

200# - 3,500#

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Wind Considerations

3. Appropriate Perimeter Condition (Structure) for “Higher” DP Regions [Plywood, 20 ga. Stud, face brick, masonry/concrete w/o edge distance and lintels.] [Assume that condition will support loads, redesign anchor as necessary, assume architect passes info to engineer of record.]

200# - 3,500#

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts



Snow Considerations

1. Appropriate Code [Code is identified 50% of time.] [Assume ASCE 7]

2. Appropriate Ground Snow Load [Ground snow load is specified in some cases, drift surcharge is rarely, if ever specified…] [Assume ground snow loads in ASCE 7, use best judgment on drift surcharge.]

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




1. Appropriate Code [Typical spec: “Curtain wall system must be designed to resist appropriate seismic forces and displacements…..”] [Assume ASCE 7, but……..]

2. Must, Must, Must have calculated interstory drift. [See above.] [Assume that our “standard” performance for fallout is less than the calculated interstory drift, communicate to architect, assume that this information is passed to Engineer of Record. This information is rarely provided.]

3. Must have Design Spectral Response Acceleration (Sds) variable to calculate seismic shear (ASCE 7, Section 9.4.1.2) [This is rarely, if ever provided in specifications] [Make a call to customer/architect. Thus far, this information is almost always provided.]

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




1. Total Vertical Deflection per Floor (not the Allowable by Code!) [Sometimes we get the LL, column shortening and creep as a maximum for all floors, all spans. Most of the time, spec reads: “…curtain wall system must be designed to accommodate deflections including, but not limited to live load, dead load, column shortening, creep and thermal expansion and contraction of the curtain wall system assuming a temperature differential of 180 deg F…”] [Assume that our standard system as quoted will meet the requirement - bad assumption. Hard splice everywhere possible to minimize moving joints. Use realistic F.]

2. Is the Total Vertical Deflection “Up and Down” or Different? [Rarely get different values for “up” and “down,” see above] [Assume same “up” and “down” deflections.]

3. (The CW Manufacturer Will Add in the Thermal Movements) […using “realistic” F…]

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




1. Appropriate Code (for DP) [No code or conflicting wind speeds – ie. 3 second gust wind speeds with fastest mile code] [Use ASCE 7.]

2. Appropriate Wind Speed (Local Codes May Override Model BC) [Conflicting wind speeds] [Use ASCE 7 wind speed map.]

3. Appropriate Perimeter Condition (Structure) for “Higher” DP Regions [You be the judge…] [Assume that condition will support loads, assume architect passes info to engineer of record.]

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts




1. Charge and Standoff Distance or Blast Load and Impulse for “Blast Design” (DoD is prescriptive) [Rarely if ever specified…]

2. Appropriate Perimeter Condition (Structure) for Short Duration Blast Loads! [Our opinion is the perimeter structure is ignored…] [Assume that condition will support loads, design anchor and connection accordingly, assume architect passes info to engineer of record. Bad assumption in the case below…]

10K – 20K

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts










Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Curtain Wall Analysis, Rules of Thumb

Basic Assumptions for the Engineer of Record When Considering CW:

1. DL of CW = 10 lb/sf

2. Assume 1/8” per 10’ of span for thermal movement

3. CW engineers assume combination of pin and roller connections

4. Most “Box Stock” CW system can only handle ¼” to ½” of total vertical movement (w/o customization).

5. Typical CW is spliced (hinged) at every 20’

6. CW/SF is very resistant to (seismic) drift, but very difficult to calculate

7. Post tension conc. slabs with minimal cover cause severe pain to CW engineers (typ. anchor bolt embedment > 2 ½”)

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Curtain Wall Analysis, Rules of Thumb

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


Reference Information

www.efcocorp.com!

Manufacturer

Of

Architectural

And

Commercial

Grade

Windows,

Curtain Walls,

Entrances,

And

Storefronts


What’s on Your Mind?

VSEC Seminar March 26, 27 2008 Virginia Beach, VA Richmond, VA David DeSutter, P.E.

Documents

Transcript of VSEC Seminar March 26, 27 2008 Virginia Beach, VA Richmond, VA David DeSutter, P.E.