architectural design options for pfbs...

Copyright © 2015 National Frame Building

Association.

ARCHITECTURAL DESIGN OPTIONS FOR PFBS

SESSION 1: POST-FRAME BUILDINGS-

A LIGHT-COMMERCIAL MAINSTAY

Copyright © 2011 National Frame Building Association

Harvey B. Manbeck, PE, PhD

Professor Emeritus of Engineering, Penn State University

Consultant to the National Frame Building Association (NFBA)

“With so many structural framing options, building

functions, and architectural finishes, post-frame building

systems are limited only by the architect’s imagination and

creativity.”

—Harvey Manbeck, PE PhD, professor emeritus at Penn State

University and NFBA technical consultant

Photo courtesy of Kistler Buildings Photo courtesy of Wick

“Post-frame contributes very well to both the environment

and the value for your dollar.”

—Cheryl Ciecko, ALA AIA LEED AP CSI GGP, technical director,

WoodWorks, a nonprofit initiative of the Wood Products Council

Photo courtesy of Lester Building Systems, LLC Photo courtesy of Fingerlakes Construction Company

Identify and/or demonstrate the :

• Versatility and range of

applications

• Structural features that

make these systems

unique

• Key performance characteristics

• Key technical resources for designing post-frame

building systems

LEARNING OBJECTIVES

Photo courtesy of Morton Buildings

Many architects and design professionals are unfamiliar

with post frame.

• It is not commonly included in traditional architectural

school curricula.

• They incorrectly equate post-frame construction with

post-and-beam construction

• They think post frame is only for agricultural buildings

(i.e., barns, storage facilities, or horse facilities).

WHAT IS POST FRAME? POST FRAME IS EVERYWHERE

Photo courtesy of Lester Building Systems, LLC


Association.

CONVENIENCE STORES


Photo courtesy of Fbi BuildingsPhoto courtesy of Wick Building

RESTAURANTS

Photo courtesy of Fbi Buildings

COMMERCIAL OFFICE AND

VETERINARY CLINICS



RELIGIOUS SPACES

Photo courtesy of Wick Buildings

PRIVATE HOMES


PUBLIC BUILDINGS


Photo courtesy of Lester Building

Systems, LLC and SL Construction


Association.

COMMUNITY BUILDINGS

Photo courtesy of Little Construction Co., Inc.

Photo courtesy of Kistler Buildings

SOCIAL, EXHIBITION & RECEPTION

HALLS

Photo courtesy of Lester Building Systems, LLC and

Eastern Iowa Building, Inc.

Photo courtesy of Lester Building Systems, LLC and

Eastern Iowa Building, Inc.

RETAIL STORES


POST-AND-BEAM CONSTRUCTION

Continuous Footer

or Pier Foundation

PostPinned

Connection

Girder

(Beam)

Floor

Concrete Pier

POST-AND-BEAM CONSTRUCTION

PostGirder

(Beam)Purlin

THIS IS POST FRAME

Figure 1. Post-frame building with trusses supported by embedded pier

foundation

Primary Frames

Wood ColumnClear Span Truss

or Rafters Embedded Pier Foundation

Truss-to-Post Connection


Association.

THIS IS POST FRAME

Figure 2. Post-frame building mounted on a concrete stem wall

Roof Purlin

Wall Girt

PRIMARY FEATURES OF POST

FRAME

Wood columns (Solid-

sawn or Laminated

Truss or

Rafters

Purlins

Sheathing

Wall girts

PRIMARY FEATURES OF POST

FRAME

21

Isolated Pier

FoundationContinuous RC

Foundation

Wall

Thickened Edge

of

Concrete Slab

THIS IS POST FRAME—PLAN VIEW

Purlin

Post

Girder (Header)

Clear Span Truss

or Roof Rafter

KEY FEATURES OF POST FRAME

Purlins

Truss

Girts

Splashboard Column

Foundation

Column

Footing

Sidewall

Column

• wood sidewall columns

• wide bay spacing—8 ft and greater

• large clear spans— up to100 ft

• embedded wood columns or concrete piers

• attached wall and roof sheathing or cladding

form structural shearwall/structural diaphragm

system for resisting lateral loads

KEY FEATURES OF POST FRAME


Association.

• Solid-sawn, glued-laminated, or mechanically

(nail) laminated wood

• Nominal 4x6, 6x6, 6x8, 8x8, or 8x10 cross

section

• Typically spaced 4, 6, 8, 12, or 16 ft on center

• Any portion of the embedded wood post must

be pressure preservative treated to AWPA-

recommended levels for ground contact

WOOD SIDE WALL COLUMNS

Spliced glued-laminated

column

• 3- or 4-ply, fabricated

with 2x lumber

• lower portion is

preservative treated

• upper portion is

untreated

WOOD SIDEWALL COLUMN

WOOD SIDEWALL COLUMNS

Nail-laminated

posts with treated

bottom spliced to

untreated top

Preservative-

treated splash

board

WOOD SIDEWALL COLUMNS

Untreated Post

Concrete Pier

PRESSURE PRESERVATIVE

TREATMENTS

• Posts embedded in

the ground, specify:

• Use category UC4B

or better per AWPA-

U1-09

• e.g., [email protected] pcf

POST FOUNDATION OPTIONS:

EMBEDDED TREATED COLUMNS

Treated


Association.

PRECAST OR CAST-IN-PLACE

REINFORCED CONCRETE PIER

• Pre-cast reinforced concrete

pier with post attached

above grade

• Entire assembly pre-

engineered

• Assembly usually fabricated

in factory and shipped to

site as a single unit

PRE-CAST REINFORCED CONCRETE

PIER

Reinforcement

Cleat

CAST-IN-PLACE CONCRETE

FOUNDATION WALL

Untreated Post

Connection

Hardware

Cast-in-Place

Concrete

Foundation Wall

THICKENED CONCRETE SLAB EDGE

THICKENED CONCRETE SLAB EDGE

• Blow-molded plastic or HDPE

plastic protective barriers

• Provide moisture and insect

protection

• “Enhance protection of copper-

based chemical treated wood

posts or laminated columns”

PROTECTIVE POST FOUNDATION

COVERS


Association.

• Pre-engineered metal plate connected 2x

lumber trusses typically spaced 4–8 ft on

center

• Heavier timber trusses for larger post and truss

spacings and aesthetic requirements

• Solid-sawn wood rafters spaced 2–4 ft on

center for shorter clear spans ≤ 30 ft

• Glulam or structural composite lumber (SCL)

rafters for larger rafter spacings or clear spans >

30 ft

ROOF FRAMING ROOF FRAMING

Trusses

Sidewall

Post

(connected

to trusses)

• Posts are connected directly to the roof framing if

post and roof framing spacing are the same

• Posts and roof framing are often connected to

header beams if post and roof framing spacing

are not the same

POST TO ROOF FRAMING

CONNECTIONS


CONNECTION

Block

Height

Block

Connection is usually a pinned connection (not a moment-resisting connection).


CONNECTION


CONNECTION


Association.

SOLID SAWN POSTS

1½”Connection with

truss fastened to

slide of post and

with bearing block

Connection

with truss

bearing on

notch in post

Typical post to truss connection details for a

solid sawn post application

• Schematic of typical

connection details

• Truss to header

(girder)

• Header (girder) to roof


CONNECTION


CONNECTION Metal Plate

Connector

Header

(Girder)

Blocking

ROOF PURLIN PLACEMENT

Purlins placed either

on top or inset

between truss top

chords or inset

between roof rafters

Purlin hangerPurlins oriented flat

or “on edge,”

depending on truss

and purlin spacing

ROOF FRAMING AND PURLINS

Typical PF system

showing pre-

engineered roof

trusses attached

to column and

roof purlins

attached to top of

the truss chords

• Typically 2x4 or 2x6 solid sawn lumber, spaced

24–32 in. apart

• Oriented “flat” on outside face of wall post when

only lateral design loads are environmental loads

• Often oriented “on edge” between adjacent posts

for additional lateral loads

WALL GIRTS


Association.

WALL GIRTS AND SHEATHING

Wall Girt

Sheating

WALL GIRTS AND SHEATHING

SECONDARY FRAMING AND

BRACING

• Corner bracing in upper chords of trusses

• Diagonal bracing for lower chords of trusses

• Lower chord stiffeners for trusses

• Cross bracing of selected compression webs

• Continuous longitudinal bracing of long

compression webs and chords of trusses

• Subtle differences from those for conventional 2

ft o.c. truss applications

• Guide to Good Practices for Handling, Installing,

Restraining & Bracing of Metal-Plate Connected

Wood Trusses (WTCA and TPI)

• B1 and B3 summary sheets: handling and

bracing trusses (truss spacing less than or equal

to 24 inches on center)

• B10 summary sheet: Post-frame truss

installation and bracing (truss spacing of 4 to 8

ft. on center)

TRUSS BRACING

The most economical PF column, roof framing,

sheathing, and foundation combination:

• laminated wood sidewall and endwall columns

• embedded post or embedded concrete isolated

pier foundations

• metal-plate connected 2x wood roof trusses and

• 26- to 29-gauge ribbed steel roof and wall

sheathing

UNIQUE FEATURES OF PF PRIMARY POST-FRAME TECHNICAL

RESOURCES

This NFBA manual

provides structural

design procedures for

post-frame building

systems.


Association.

• ANSI/ASAE (ASABE) EP 484 for diaphragm

design of metal-clad, post-frame rectangular

buildings

• ANSI/ASAE (ASABE) EP 486 for shallow post

foundation design

• ANSI/ASAE (ASABE) EP 559 for design

requirements and bending properties for

mechanically laminated columns

• Available at www.asabe.com

PRIMARY PF TECHNICAL

RESOURCESVisit PostFrameAdvantage.com for more information

about:

• Monthly webinars for design professionals

• Online University courses for design professionals

- Architectural Design Options for PFBS (3 – 1

hour sessions)

- Engineering Design of PFBS (5 – 1 hour

sessions)

* Free

* CE credits available for design professionals

WANT MORE TECHNICAL INFO?

Copyright © 2011 National Frame Building Association

• Cost-effectiveness

• Energy efficiency

• Code compliance

• Sustainability

• Design flexibility

• Durability and strength

SESSION 2: ARCHITECTURAL DIVERSITY

OF POST-FRAME BUILDING SYSTEMS

• National Frame Building

Association (NFBA)

• www.postframeadvantage.com

• www.NFBA.org

• NFBA

8735 Higgins Road

Suite 300

Chicago, IL 60631

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