ASTM F537-01(2019)

Standard Specification for Design, Fabrication, and Installation of Fences Constructed of Wood and Related Materials

ABSTRACT
This specification covers the design, fabrication, and installation practices for wood fences, including fences combined with wood and other materials, that are based on fundamental construction principles combined with long-standing traditional fence building skills. This specification also provides a systematic method of purchase, inspection with basis for rejection, and certification of manufactured wood fences by the fence industry. The generic classifications for wood fencing covered here are the rail fences (Type I), board fences (Type II), picket fences (Type III), and solid panel fences (Type IV).
SCOPE
1.1 This specification covers all wood fences, including fences combined with wood and other materials.  
1.2 This specification covers three classifications of wood fences. This specification is based on fundamental construction principles combined with long-standing traditional fence building skills, and covers the design, fabrication, and installation practices of wood fences.  
1.3 This specification also provides a systematic method of purchase, inspection with basis for rejection, and certification of manufactured wood fences by the fence industry.  
1.4 The values stated in inch-pound units are to be regarded as the standard. Acceptable industry-wide SI equivalents are being developed.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2019
• ICS: 91.090 - External structures
• Technical Committee: F14 - Fences
• Drafting Committee: F14.10 - Specific Applications and Other Fence Systems and Components

Relations

• Refers: ASTM F1667-18 - Standard Specification for Driven Fasteners: Nails, Spikes, and Staples
• Effective Date: 01-Sep-2018
• Refers: ASTM F1043-17a - Standard Specification for Strength and Protective Coatings on Steel Industrial Fence Framework
• Effective Date: 01-Jun-2017
• Refers: ASTM F1667-17 - Standard Specification for Driven Fasteners: Nails, Spikes, and Staples
• Effective Date: 01-Mar-2017
• Refers: ASTM F1043-17 - Standard Specification for Strength and Protective Coatings on Steel Industrial Fence Framework
• Effective Date: 01-Feb-2017
• Refers: ASTM F1043-16a - Standard Specification for Strength and Protective Coatings on Steel Industrial Fence Framework
• Effective Date: 01-Jun-2016
• Refers: ASTM F1043-16 - Standard Specification for Strength and Protective Coatings on Steel Industrial Fence Framework
• Effective Date: 01-Feb-2016
• Refers: ASTM F1667-15 - Standard Specification for Driven Fasteners: Nails, Spikes, and Staples
• Effective Date: 01-Sep-2015
• Refers: ASTM F1043-14 - Standard Specification for Strength and Protective Coatings on Steel Industrial Fence Framework
• Effective Date: 01-Oct-2014
• Refers: ASTM F1667-13 - Standard Specification for Driven Fasteners: Nails, Spikes, and Staples
• Effective Date: 01-Dec-2013
• Refers: ASTM F1043-13 - Standard Specification for Strength and Protective Coatings on Steel Industrial Fence Framework
• Effective Date: 01-Nov-2013
• Refers: ASTM B221-13 - Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
• Effective Date: 01-Apr-2013
• Refers: ASTM F1043-12 - Standard Specification for Strength and Protective Coatings on Steel Industrial Fence Framework
• Effective Date: 15-Nov-2012
• Refers: ASTM B221-12a - Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
• Effective Date: 15-Nov-2012
• Refers: ASTM B221-12 - Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
• Effective Date: 15-Jan-2012
• Refers: ASTM F1667-11ae1 - Standard Specification for Driven Fasteners: Nails, Spikes, and Staples
• Effective Date: 01-Nov-2011

Overview

ASTM F537-01(2019) - Standard Specification for Design, Fabrication, and Installation of Fences Constructed of Wood and Related Materials provides standardized guidelines for contractors, designers, inspectors, and manufacturers involved in wood fence construction. Developed by ASTM International, this standard defines classifications, performance criteria, quality requirements, and best practices for resilient, safe, and attractive wood and composite fencing.

This specification addresses fundamental principles of fence building and incorporates traditional craftsmanship with modern quality standards. It covers fences entirely of wood, as well as fences that combine wood with other materials, ensuring consistent performance and appearance throughout the lifespan of the installation.

Key Topics

• Fence Classifications: The standard identifies four primary categories of wood fences:

  • Type I: Rail Fences (including split, post and rail, and round rail)
  • Type II: Board Fences (solid, spaced, shadow box, louver, weave, and basket weave)
  • Type III: Picket Fences (sawn picket, grape stake, stockade, and wire-bound)
  • Type IV: Solid Panel Fences (including plywood and other panel product fences)

• Design & Construction Guidance: It provides details on:

  • Selection of lumber and related materials
  • Specifications for posts, rails, boards, and pickets
  • Attachment and installation methods
  • Pressure treatment and corrosion-resistance requirements

• Inspection & Certification: Includes a systematic approach for:

  • Purchase and documentation of fence components
  • Inspection procedures and rejection bases
  • Certification requirements for manufactured fence products

• Quality Control: Outlines wood grading and quality standards for posts, rails, boards, and treated wood, referencing recognized lumber organizations and preservation standards.

Applications

ASTM F537-01(2019) offers broad practical value for a range of stakeholders:

• Residential: Ensures privacy, safety, and decorative garden boundaries with durable wood fencing.
• Agricultural: Specifies dimensions and treatments for livestock enclosures, property demarcation, and rural security.
• Commercial and Institutional: Guides installation of fences for schools, parks, public spaces, and businesses, balancing security, aesthetics, and code compliance.
• Municipal and Industrial: Applies to perimeter, safety, and zoning fences using wood or wood-composite materials.

By adhering to these specifications, projects benefit from:

• Reliable material performance across climates and environments
• Interchangeable, industry-standard fencing components
• Enhanced safety, structural integrity, and aesthetic consistency
• Defined methods for quality assurance during procurement and installation

Related Standards

ASTM F537-01(2019) references and is supported by several other key standards:

• ASTM F1043: Specification for strength and protective coatings for steel fence framework
• ASTM F1667: Specification for driven fasteners: nails, spikes, and staples
• AWPA (American Wood Protection Association) Standards: For preservative treatment of wood (C1, C2, C5, C9, C16, M4, C23)
• Voluntary Product Standards (PS20, PS1): For softwood lumber and plywood
• National Design Specifications (NFPA): For stress-graded lumber and fastenings

These related specifications work together to ensure all components in wood and composite fences meet rigorous performance and safety requirements.

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Keywords: ASTM F537-01, wood fence standard, wood fence design, wood fence fabrication, wood fence installation, wood fence inspection, fencing specification, wood fencing materials, quality control, pressure-treated wood, board fence, picket fence, rail fence, panel fence, lumber grading, fence certification, fencing industry standards.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:F537 −01 (Reapproved 2019)
Standard Specification for
Design, Fabrication, and Installation of Fences Constructed
of Wood and Related Materials
ThisstandardisissuedunderthefixeddesignationF537;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope for Preparing Pentachlorophenol Solutions (Withdrawn
1992)
1.1 This specification covers all wood fences, including
D3225Specification for Low-Boiling Hydrocarbon Solvent
fences combined with wood and other materials.
for Oil-Borne Preservatives (Withdrawn 2006)
1.2 This specification covers three classifications of wood
D3506Specification for Inhibited Grade Methylene Chlo-
fences.Thisspecificationisbasedonfundamentalconstruction
ride for Preparing Pentachlorophenol Solutions (With-
principlescombinedwithlong-standingtraditionalfencebuild- 3
drawn 1992)
ing skills, and covers the design, fabrication, and installation
F1043Specification for Strength and Protective Coatings on
practices of wood fences.
Steel Industrial Fence Framework
F1667SpecificationforDrivenFasteners:Nails,Spikes,and
1.3 This specification also provides a systematic method of
purchase, inspection with basis for rejection, and certification Staples
2.2 Federal Standards:
of manufactured wood fences by the fence industry.
TT-W-572B Fungicide: Pentachlorophenol
1.4 Thevaluesstatedininch-poundunitsaretoberegarded
2.3 Canadian Standards Association Document:
as the standard. Acceptable industry-wide SI equivalents are
B111-74Specification for Wire Nails, Spikes, and Staples
being developed.
2.4 National Forest Products Association Standard:
1.5 This international standard was developed in accor-
National Design Specification for Stress Grade Lumber and
dance with internationally recognized principles on standard-
Its Fastenings
ization established in the Decision on Principles for the 7
2.5 Voluntary Product Standards:
Development of International Standards, Guides and Recom-
PS20-70Softwood Lumber
mendations issued by the World Trade Organization Technical
PS1-74 Softwood Plywood
Barriers to Trade (TBT) Committee. 8
2.6 American Plywood Association Standard:
Specification for Plywood Design
2. Referenced Documents
2.7 American Wood Preservers Association Standards:
2.1 ASTM Standards:
C1AllTimberProducts,PreservativeTreatmentbyPressure
A641/A641MSpecification for Zinc–Coated (Galvanized)
Process
Carbon Steel Wire
C2Lumber, Timbers, Bridge Ties, Mine Ties, Preservative
A809 Specification for Aluminum-Coated (Aluminized)
Treatment by Pressure Process
Carbon Steel Wire
C5Fence Post, Preservative Treatment by Pressure Process
B221Specification forAluminum andAluminum-Alloy Ex-
truded Bars, Rods, Wire, Profiles, and Tubes
The last approved version of this historical standard is referenced on
D2605Specification for Volatile Petroleum Solvent (LPG)
www.astm.org.
AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
1 5
ThisspecificationisunderthejurisdictionofASTMCommitteeF14onFences Available from Canadian Standards Association, 178 Rexdale Blvd., Rexdale,
and is the direct responsibility of Subcommittee F14.10 on Specific Applications Ontario, Canada M9W 1R3.
and Other Fence Systems and Components. AvailablefromNationalForestProductsAssociation,1619MassachusettsAve.,
Current edition approved Oct. 1, 2019. Published October 2019. Originally N.W., Washington, DC 20036.
approvedin1978.Lastpreviouseditionapprovedin2014asF537–01(2014).DOI: Available from U.S. Department of Commerce, National Bureau of Standards,
10.1520/F0537-01R19. Washington, DC 20234.
2 8
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from American Plywood Association, 1119 A St., Tacoma, WA
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM 98401.
Standards volume information, refer to the standard’s Document Summary page on Available from American Wood Preservers Association, P.O. Box 849,
the ASTM website. Stevensville, MD 21666.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F537−01 (2019)
C9Plywood, Preservative Treatment by Pressure Process 3.2.7 pencilpoint—apicketorboardthatisconicalinshape,
C16Wood Used on Farms, Preservative Treatment by Pres- and common to round and half-round pickets.
sure Process
3.2.8 standard clipped corners (or dog-eared corners)—
C23RoundPolesandPostsUsedForBuildingConstruction,
corners which are clipped diagonally (approximately 45°).
Preservative Treatment by Pressure Process
3.2.9 standard point—a picket or fence board cut to a point
M4 Care of Pressure Treated Wood Products
at approximately 45° angles.
3.2.10 posts—fence posts are specified by the desired shape
3. Terminology
or manufacture of their above ground tops as described in
3.1 Definitions:
3.2.11 through 3.2.15.
3.1.1 back rails—rails on which cover material is directly
3.2.11 chamfered posts—in round or square posts, the shal-
attached.
low diagonal cut or easing of the otherwise square-cut end.
3.1.2 boards—lumberthatisupto1in.innominalthickness
3 1
Usually measures from ⁄4to 1 ⁄2 in. along the chamfer.
and 2 in. or wider in nominal width.
3.2.12 diamond-point posts—the pyramid-shaped ends of
3.1.3 cover material—the face or fill material attached to a
post which are formed by angle cuts of approximately 45°.
fence structural frame.
3.2.13 domed posts—roundedendsofeitherroundorsquare
3.1.4 custom fence design—any fence design that is signifi-
posts.
cantly different from those described in this specification.
3.2.14 flattop fence posts—the square cut ends of post.
Custom fence designs are also required to meet all require-
ments regarding materials, fabrication, installation,
3.2.15 pencil-pointposts—conicallyshapedroundposttops.
workmanship, and structural equivalency as set forth within
this specification.
4. Classification of Standard Fence Types
3.1.5 panel products—all modular products available in
4.1 The generic classifications of wood fencing in 4.2
standardized rectangular panels, many of which are suited to
through 4.5 have gained common recognition throughout the
exterior applications such as privacy fencing. Examples are
fence industry and are adapted to this specification as a means
plywood, fiberglass, and corrugated metals.
of identifying a basic fence type. These classifications may be
used in all cases as part of the purchase agreement between
3.1.6 pickets—narrow wood members that are sawn, split,
buyers and sellers of wood fencing; except a detailed
sliced, milled, natural round or half-round, and are approxi-
description, drawing, or rendering of a custom fence design
mately 2 to 4 in. in face or coverage width.
may be substituted where necessary.
3.1.7 posts—the vertical structural support members of the
4.2 Type I—Rail Fences:
fence frame.
4.2.1 Split Rail—The common country fence of alternating
3.1.8 rails—the horizontal structural support members of
layers of handsplit rails laid up in zigzag tiers.
the fence frame.
4.2.2 SplitorSawnPostandRail,orBoth—Therusticfence
3.1.9 slats or weave boards—the horizontal or vertical
made up of split or sawn rails (two to four rails) installed into
3 3
membersusedinbasketweavetypefencesnormally ⁄8to ⁄4in.
slotted split or sawn posts.
thick and 3 in. or wider in nominal width.
4.2.3 Round Post and Rail—A fence similar to that de-
3.1.10 standard fence design—anyfencestructuralframeor
scribed in 4.2.2, except posts and rails are round or natural
fence-type classification covered within this specification. shaped; normally produced in two, three, and four rail fences.
The rails are machined at ends to form a paddle-shaped scarf
3.2 Definitions of Terms Specific to This Standard:
jointtobeinstalledintopostslotsorformedintodoweledends
3.2.1 boards or pickets—fence boards or pickets are speci-
for installing into posts with round connections.
fied by the desired shape or manufacture of the upright end
4.2.3.1 Herringbone Pattern Round Post and Rail—Afence
when installed vertically as described in 3.2.2 through 3.2.9.
as described in 4.2.3, except it is normally a three-rail fence
3.2.2 California clipped corners—corners similar to 3.2.8,
with small round wood inserts (doweled) which are installed
except the clip angle is steeper at approximately 65°.
between the upper two rails to form the familiar herringbone
pattern.
3.2.3 diamond point—a board or picket similar to the
standard point (3.2.9), except it consists of additional angular 4.2.3.2 English Hurdle Fence—A standard post and rail
cuts, front and back, so that the top appears as a triangle from fence as described in 4.2.2 and 4.2.3, except that two smaller
four angles of view, or pyramid shaped. rails are installed diagonally from the fence posts (usually
below the bottom rail connection) extending upwards to just
3.2.4 flattop—a simple flat or 90° square cut end.
above the fence top rail where they intersect and join a third
3.2.5 gothic—apicketorboardinwhichtheshapeisformed
decorative rail of the same approximate size, which extends
by two arc-shaped cuts that meet at center to form a graceful
downward to just below the bottom rail at a perpendicular
point at the top.
angle.
3.2.6 handsplit—pickets, posts, and rails which are split by 4.2.4 Post and Board—The fence often referred to as corral
machine or by hand using an axe or froe, etc. fenceisnormallyconstructedusingsawnwoodposts,although
F537−01 (2019)
round wood posts are sometimes used, with boards serving as The pickets may be installed solid or by specified spacing
rails. They are commonly constructed in two, three, or four where desired for light and ventilation.
board configurations.
4.4.2 Grape Stake Picket—A fence that is sometimes re-
4.2.4.1 Crossbuck Post and Board—Afence as described in
ferred to by the picket type, either handsplit or machine sliced.
4.2.4, except that two boards diagonally cross each other
This is a popular fence in the durable species and is usually
between two standard top and bottom board rails.
constructed with handsplit or machined back rails and posts. It
4.2.4.2 Crossbuck Post and Rail—A fence as in 4.2.4.1,
is most often installed with solid picket cover, but can be
except rails are 2-in. or thicker nominal lumber.
utilized as a spaced picket fence.
4.2.4.3 Hurdle Post and Board—A fence having the same
4.4.3 Stockade Picket—A fence that is similar to other
geometric arrangement as the English hurdle fence in 4.2.3.2,
picket fences, except the pickets are natural, machine milled,
except all rails are sawn boards.
round, or sliced to half-round; and are available with bark
4.2.4.4 Hurdle Post and Rail—A fence as described in
removed, or with bark on for an added rustic effect.This fence
4.2.4.3,excepttopandbottomrailsare2in.orthickernominal
is popular in common wood species, and may be installed to
lumber.
round wood posts and round or half-round back rails, sawn
4.3 Type II—Board Fences: Every design within this type
posts, and back rails; or back rails attached to metal posts.
may be supported by sawn wood posts, round wood posts, or
4.4.4 Wire-Bound Picket—This fencing is wire-bound,
metal posts.
wooden picket fencing, in roll form. It is used for applications
4.3.1 Solid Board Fence—A fence that is constructed of
such as but not limited to, snow, shade, safety, sand, and
ordinary wood fence boards which are usually installed
screening. The fence is fabricated with a 2- or 4-in. maximum
vertically, but occasionally horizontally or diagonally, over a
rather conventional fence frame of from two to four rails spacing between pickets as specified by the purchaser. Each
between posts. picket is held firmly by five pairs of zinc-coated wires. Each
4.3.2 Spaced Board Fence—A fence as described in 4.3.1,
pair of wires is tightly twisted by rotating a twister head a
except that open space is provided between the boards either
minimum of 2½ complete revolutions (900° of rotation) for
for eye appeal or for ventilation.
2-in.spacingand5completerevolutions(1800°ofrotation)for
4.3.3 Shadow Box—A fence that is constructed like a solid
the 4-in. spacing.
board fence (see 4.3.1), except that fence boards are installed
4.4.4.1 The twist rotation shall be in opposite directions
alternately from one side of the fence rails to the other,
between each succeeding picket. The wire shall have a mini-
providing interesting shadow lines as well as excellent venti-
mum coated diameter of 0.099 in. (12 ⁄2 gage) and a minimum
lation. This fence is commonly offered in either vertical or
zinc coating of 0.30 oz/ft (Specification A641/A641M, Class
horizontal panels.
1) or a minimum aluminum coating of 0.32 oz/ft (Specifica-
4.3.4 Louver—A fence which is similar to common board
tion A809) as selected by the purchaser. It shall have a
fences (4.3.1) in frame configuration, except that fence boards
minimum tensile strength of 70 000 psi in accordance with
areinstalledangularlybetweenthefencerailswiththeeffectof
Specification A641/A641M or Specification A809, Medium
directingsunlightandairinadesirableway.Thesefencesmay
Temper. The wire spacing of top and bottom pairs of wires
be constructed with the board louvers installed vertically or
shallbenotlessthan3in.andnotmorethan6in.fromtheends
horizontally.
of the pickets, with the remaining pairs of wires spaced
4.3.5 Weave—A fence similar to the shadow box (4.3.3),
equidistant between the top and bottom wires.
except each individual fence board, normally 1 in. nominal in
4.4.4.2 The length of roll of fabricated fence shall be 50 ft
thickness, is alternately attached to one side of the top rail and
the opposite side of the bottom rail. It may be constructed 6 6 in. The pickets shall be made of spruce, hemlock, cedar,
vertically as described, or horizontally (minus rails) by alter- redwood, fir, or pine, air-dried and rough sawn. The pickets
nating installation of the boards directly to the fence posts.
may be stained, painted with a red oxide coating, or pressure-
4.3.6 Basket Weave—A fence similar to the weave (4.3.5),
treated in accordance with 9.4 as specified. Picket dimension
3 3
3 1 1
except basket boards (commonly ⁄8to ⁄4in. in thickness) are
shallbe:length,either48or72 6 ⁄16in.;width,1 ⁄2 6 ⁄16in.;
3 1
woven alternately between from one to five small wood
and thickness, ⁄8 6 ⁄16in.
members (sometimes 1 by 2, 1 by 3, or 1 by 4-in. nominal),
4.5 Type IV—Solid Panel Fences: Every design within this
which extend through the height of the weave perpendicularly.
typemaybesupportedbysawnwoodposts,roundwoodposts,
The fence may contain either a vertical or horizontal weave,
or metal posts.
butineitherform,thetopandbottomrailsmayberequiredfor
rigidity. The basket weave fence requires high quality wood 4.5.1 Plywood Panel Fences—A fence which includes any
because of its relative thinness. common post and back rail construction with an exterior grade
of plywood that is installed on or within the frame.
4.4 Type III—Picket Fences: Every design within this type
4.5.2 Other Panel Product Fences—Other panel products
may be supported by sawn wood posts, round wood posts, or
suitable for exterior use and manufactured in standard panel
metal posts.
sizes may be installed within any fence frame that provides
4.4.1 Sawn Picket—Afence in which the pickets are from 2
adequate lateral support for the panel. Examples include
to 4-in. nominal width and are installed vertically. The pickets
may be installed over two to four back rails of sawn lumber. corrugated fiberglass and corrugated metals.
F537−01 (2019)
5. Ordering Information 5.1.4 SpeciesofWood—Itisnormallydesirableforthefence
purchasertospecifythecommercialspeciesofwoodtobeused
5.1 Complete information describing the desired fence
in the fence or its various component parts, as it relates vitally
productshallbeprovidedwithallpurchaseordersorinquiries.
to the appearance, durability, and general performance of the
The information described in 5.1.1 through 5.1.10 shall be
fence structure (see Section 8).
included as detailed within this specification:
5.1.5 Preservative Pressure Treatment—Specify the pres-
5.1.1 Fence-Type Classification or Description—Provide
sure treatment, where applicable, in accordance with AWPA
the standard fence-type classification, as described in Section
Standards C1, C2, C5, C9, C16, C23, and M4 (see Section 9).
4, or substitute a detailed description, drawing, or architectural
5.1.6 Sizes and Details for Cover Material(s)—Sizes of
rendering, depending on the complexity of a custom design,
boards, pickets, and other fence cover materials (such as
and the requirements of the fence supplier.
basketweavestock)shallbeincludedinallpurchaseordersand
5.1.2 Structural Frame Identification Number—Provide the
inquiries. Unless otherwise noted, all fence boards shall be
fence structural frame identification index number as provided
taken to be 1 in. rough nominal in thickness. Details of cover
in Tables 1-3 (see also Section 7).Also, specify the maximum
material selection should be included where necessary (for
post spacing in feet, center to center of posts and the height of
example, nominal face widths of fence boards or pickets
the fence, which is the minimum measurement from ground
should be specified, including the style in which they are
level to the top of the cover material or top of the top rail,
laid-up). Sizes are provided in Section 10.
whichever is the greater when options are provided for a
5.1.7 Manufacture—Special shapes or dressed ends of ver-
particular fence frame in the tables. For open post and rail
tical fence boards, pickets, or posts shall be specified by the
fences, specify the desired number of rails where shown to be
terminology provided in Section 3. Round post and rail fences
optional in Table 1. The fence frames listed in Tables 1-3 and
may be specified with paddle-shaped scarf joints in cases
Section 7 provide many common fence frame configurations
where rail scarfs are fitted into slotted posts; or rails may be
and may be used for simplified specifying.Alternatively, fence
manufactured with doweled ends for installation into posts
frames of significantly different design may be used if they
with special round-hold connections. Other special manufac-
providestructuralintegrityequalorsuperiortothosedescribed
turing details may be specified by including a detailed
in Section 7, or if justified by structural engineering as
description, drawing, or rendering of the fence.
provided in NFPA Specification for Stress Grade Lumber and
5.1.8 Post Embedment—Therequiredfencepostinstallation
Its Fastenings and APA Specification for Plywood Design.
shall be specified as compact soil embedment, gravel or
5.1.3 Architectural Class or Grade of Materials—Include
sand-gravel embedment, or set in concrete collar footings in
the architectural class of all sawn posts, rails, or boards as
accordance with Section 11. However, if the fence is installed
provided in Section 6 or their acceptable equivalent commer-
by the purchaser, only the required post length need be
cial lumber grade as provided in Tables 4-7. If handsplit,
specified, based on the depth of embedment as determined in
machine-sliced, or sawn pickets are to be used, specify the
accordance with Section 11.
architectural class in accordance with Section 6. All other
wood products are required to meet their minimum quality 5.1.9 Fastenings and Connections—This aspect of fence
standards as established within Section 6. construction may be specified with considerable detail or may
TABLE 1 Open Frame Post and Rail Fences
Above Total
Structural Nominal Nominal Bot-
Fence Type Nominal Post Nominal Top Post Spac- Ground Number of
Frame Identi- Center tom Rail
Classification Size, in. Rail Size, in. ings, ft Height of Rails per
fication Index Rail(s), in. Size, in.
Fence, ft Section
1 1 1 1 1 1
Split post No. 1 3 ⁄2 by 3 ⁄2 1 ⁄2 by 1 ⁄2 . 1 ⁄2 by 1 ⁄2 63 2
and rail No. 2 4 by 4 2 by 3 . 2 by 3 8 4 2
No. 3 4 by 4 2 by 3 2 by 3 2 by 3 8 4 3
No. 4 4 by 5 2 by 4 . 2 by 4 10 5 2
No. 5 4 by 5 2 by 4 2 by 4 2 by 4 10 5 3
No. 6 5 by 5 2 by 3 2 by 3 2 by 3 8 6 3
No. 7 5 by 5 2 by 4 . 2 by 4 10 6 2
No. 8 5 by 5 2 by 4 2 by 4 2 by 4 10 6 3
Round post No. 9 4 diameter . 3 diameter . 8 1, 2 1
and rail No. 10 5 diameter . 4 diameter . 8 to 10 1, 2 1
No. 11 4 diameter 3 diameter . 3 diameter 8 2, 3, 4 2
No. 12 4 diameter 3 diameter 3 diameter 3 diameter 8 3, 4, 5 3
No. 13 5 diameter 4 diameter . 4 diameter 8 to 10 3, 4, 5 2
No. 14 5 diameter 4 diameter 4 diameter 4 diameter 8 to 10 4, 5, 6 3
No. 15 5 diameter 4 diameter 4 diameter 4 diameter 8 to 10 5, 6, 7 4
Sawn post No. 16 3by4 1by4 . 1by4 8 2 2
and board No. 17 4by4 1by4 1by4 1by4 8 3, 4, 5 3, 4, 5
No. 18 4by4 1by6 1by6 1by6 8 4, 5, 6 3, 4, 5
F537−01 (2019)
TABLE 2 Sawn Wood Fence Frames
Total
Structural Nominal Above
Nominal Nominal Nominal Number
Fence Type Frame Iden- Bottom Post Spac- Ground
Post Size, Top Rail Center of Rails
Classification tification Rail Size, ings, ft. Height of
in. Size, in. Rail(s), in. per Sec-
Index in. Fence, ft
tion
Fence frames for use No.19 3by4 2by3 . 2by3 6 3,4 2
with cover materials
(up to and including
solid, 100 %, cover
or fill designs)
No.20 4by4 2by3 . 2by3 8 3,4 2
No.21 4by4 2by3 2by3 2by3 8 4,5,6 3
No.22 4by4 2by4 . 2by4 8 4,5,6 2
No.23 4by4 2by4 2by4 2by4 8 6 3
No.24 4by4 2by6 . 2by6 8 6 2
No.25 4by4 4by4 . 4by4 8 6 2
No.26 4by6 2by4 2by4 2by4 6 7 3
No.27 4by6 2by6 . 2by6 6 7 2
No.28 4by6 4by4 . 4by4 6 7 2
No.29 6by6 2by6 2by6 2by6 6 8 3
No.30 6by6 4by4 4by4 4by4 6 8 3
No.31 6by6 2by4 2by4 2by4 6 8 4
No.19A 3by4 1by4 . 1by4 6 3 2
No.20A 3by4 1by4 1by4 1by4 6 4,5 3
No.21A 4by4 1by4 1by4 1by4 8 4,5,6 3
TABLE 3 Metal Fence Posts and Frames
Struc-
Nominal Out- Nominal Total
tural Above
side Diameter Nominal Top Center Nominal Bot- Post Number
Fence Type Frame Ground
or Dimensions Rail Size- Rail- tom Rail- Spacings, of Rails
Classification Identifi- Height of
of Metal Posts, Wood, in. Wood, Wood, in. ft per Sec-
cation Fence, ft
in. in. tion
Index
Metal/wood fence frames for use No. 1M 1.90 2 by 3 . 2 by 3 8 3 to 4 2
with cover materials (galva-
nized steel pipe) No. 2M 1.90 2 by 3 2 by 3 2 by 3 8 4 to 5 3
No. 3M 1.90 2 by 4 . 2 by 4 8 4 to 5 2
No.4M 2.375 2by3 2by3 2by3 8 4,5,6 3
No. 5M 2.375 2 by 4 . 2 by 4 8 4, 5, 6 2
No.6M 2.375 2by4 2by4 2by4 8 5to6 3
Same usage as above but post No. 7M 1.875 by 1.625 2 by 3 2 by 3 2 by 3 8 3 to 4 2
and rails are metal channels No. 8M 1.875 by 1.625 2 by 3 . 2 by 3 8 4 to 5 3
No. 9M 1.875 by 1.625 2 by 4 2 by 4 2 by 4 8 4 to 5 2
No. 10M 2.25 by 1.70 2 by 3 2 by 3 2 by 3 8 4, 5, 6 3
No.11M 2.25by1.70 2by4 . 2by4 8 4,5,6 2
No. 12M 2.25 by 1.70 2 by 4 2 by 4 2 by 4 8 5 to 6 3
No.13M 2.375×2alumi- 2.375×2alumi- . 2.375×2alumi- 6to10 3to6 2
num num num
No. 14M 2.375 × 2 galva- 2.375 × 2 galva- . . . 2.375 × 2 galva- 6to10 3to6 2
nized steel nized steel nized steel
be omitted, in which case all fastenings and connections shall lumber which are acceptable alternatives and in reasonable
comply with Section 11. accordance with these architectural quality classifications.
5.1.10 Finish—When and if a special finish is desired, the Tables 4-7 relate commercial lumber grades by size and use
color, method of application, and number of coats shall be categories to the following fence industry component-part
specified (see Section 12). quality classifications:
6.1.1 Architectural Class I, Sawn Posts and Rails—This
6. Quality of Materials of Manufacture
classification is recommended where the highest combination
of both strength and appearance is required.Allowable growth
6.1 Quality Classification of Sawn Posts and Rails—The
followingqualityclassificationsofsawnlumberpostsandrails characteristics and limiting provisions are described in 6.1.1.1
through 6.1.1.7.
maybeachievedbyrippingorcrosscuttingcommercialgrades
of lumber to meet the requirements as listed. Compliance can 6.1.1.1 Stained sapwood allowed, stained heartwood in
also be achieved by using the minimum commercial grades of 25% of the piece.
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TABLE 4 Lumber for Fence Boards (2 in. and Wider)
A
Species Architectural Class I Architectural Class II Architectural Class III Grade Rule Writing Agencies
Western Red Cedar select quality utility ICA
select quality utility NLGA
Western Cedars (Incense and select merchantable standard/construction utility WCLIB, WWPA, NLGA
Red) 2 and btr common 3 common 4 common WWPA, NLGA
Cypress 1 common 2 common 3 common or peck SCMA, NHLA
Douglas Fir-Larch select merchantable standard/construction utility WCLIB, WWPA, NLGA
Douglas Fir-Larch 2 and btr common 3 common 4 common WWPA, NLGA
Hem-Fir (Hemlock-White Fir) select merchantable standard/construction utility WCLIB, WWPA, NLGA
2 and btr common 3 common 4 common WWPA, NLGA
Western or Idaho sterling standard utility WWPA, NLGA
White Pine
Western Pines 2 and btr common 3 common 4 common WWPA, NLGA
Norway Pine premium premium standard NELMA
Eastern White Pine premium premium standard NELMA
Eastern White Pine 2 and btr common 3 common 4 common NLGA
Northern Pine and Norway Pine 2 and btr common 3 common 4 common NHPMA, NELMA, NLGA
(NHPMA)
Southern Pine No. 1 boards No. 2 boards No. 3 boards SPIB
Eastern Hemlock and Tamarack 2 and btr common 3 common 4 common NHPMA, NELMA
Aspen-Alder 2 and btr common 3 common 4 common NHPMA, NELMA, NLGA, WWPA
Balsam Fir and Eastern Spruce 2 and btr common 3 common 4 common NHPMA, NELMA, NLGA
Englemann Spruce 2 and btr common 3 common 4 common WWPA
Sitka Spruce select merchantable standard/construction utility WCLIB, NLGA
Spruce-Pine-Fir 2 and btr common 3 common 4 common NLGA
Redwood select heart or select construction heart or con- merchantable RIS
Redwood struction common RIS
Northern White 2 and btr common 3 common 4 common NELMA, NLGA
Cedar
Alpine Fir 2 and btr common 3 common 4 common WWPA, NLGA
All hardwoods No. 1 construction No. 2 construction No. 3 construction NLHA, SHLMA
A
For identification of agencies, refer to Appendix X2.
TABLE 5 Lumber for Posts and Rails (2 to 4 in. Thick and 2 to 4 in. Wide)
A
Species Architectural Class I Architectural Class II Architectural Class III Grade Rule Writing Agencies
Western Red Cedar select quality utility ICA
Western Cedars (Incense and construction/No. 2 standard, No. 3, or stud utility WWPA, WCLIB, NLGA
Red)
Cypress 1 common 2 common 3 common SCMA, NHLA
Douglas Fir-Larch construction/No. 2 standard, No. 3, or stud utility WWPA, WCLIB, NLGA
Hemlock-Fir construction/No. 2 standard, No. 3, or stud utility WWPA, WCLIB, NLGA
Western Pine construction/No. 2 standard, No. 3, or stud utility WWPA, NLGA
Eastern White Pine construction/No. 2 standard, No. 3, or stud utility NELMA, NHPMA, NLGA
Western or Idaho White Pine construction/No. 2 standard, No. 3, or stud utility WWPA, NLGA
Northern Pines construction/No. 2 standard, No. 3, or stud utility NELMA, NHPMA, NLGA
Southern Pine construction/No. 2 standard, No. 3, or stud utility SPIB
Eastern Hemlock, Tamarack construction/No. 2 standard, No. 3, or stud utility NELMA, NHPMA
Aspen-Alder construction/No. 2 standard, No. 3, or stud utility NELMA, NHPMA, NLGA
Balsam Fir, Eastern Spruce construction/No. 2 standard, No. 3, or stud utility NELMA, NHPMA, NLGA
Engelmann Spruce construction/No. 2 standard, No. 3, or stud utility WWPA
Sitka Spruce construction/No. 2 standard, No. 3, or stud utility WCLIB, NLGA
Spruce, Pine, Fir construction/No. 2 standard, No. 3, or stud utility NLGA
Redwood select, select heart, or construction common, construc- merchantable utility RIS
No. 2 open grain tion heart, or No. 3 open
grain, standard stud
Alpine Fir construction/No. 2 standard, No. 3, or stud utility WWPA, NLGA
All hardwoods No. 1 dimension No. 1 dimension No. 2 dimension NHLA, SHLMA
Northern White Cedar construction/No. 2 standard, No. 3, or stud utility NELMA, NLGA
A
For identification of agencies, refer to Appendix X2.
6.1.1.2 Seasoning checks not limited except through checks 6.1.1.5 Slopeofgrain,nottoexceeda1-in.deviationin8in.
at end limited as splits; allowable splits equivalent in length to of length.
the width of the piece. 6.1.1.6 No spike knot or other growth characteristic shall
6.1.1.3 Knots, sound and tight, approximately one third the displace more than one third of a cross-sectional area.
face width; small unsound or not firmly fixed knots allowed. 6.1.1.7 Wane, one sixth of any face; or one fourth of any
6.1.1.4 Skips, hit and miss. faceuptohalfthelength;exceptanoccasionalpiecemayhave
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TABLE 6 Lumber for Posts and Rails (2 to 4 in. Thick and 6 in. and Wider)
A
Species Architectural Class I Architectural Class II Architectural Class III Grade Rule Writing Agencies
Western Red Cedar select quality utility ICA
Western Cedars (Incense and No. 1 No. 2 No. 3 WWPA, WCLIB, NLGA
Red)
Cypress 1 common 2 common 3 common SCMA, NHLA
Douglas Fir-Larch No. 1 No. 2 No. 3 WWPA, WCLIB, NLGA
Hemlock-Fir No. 1 No. 2 No. 3 WWPA, WCLIB, NLGA
Western Pine No. 1 No. 2 No. 3 WWPA, NLGA
Eastern White Pine No. 1 No. 2 No. 3 NELMA, NHPMA, NLGA
Western or Idaho White Pine No. 1 No. 2 No. 3 WWPA, NLGA
Northern Pines No. 1 No. 2 No. 3 NELMA, NHPMA, NLGA
Southern Pine No. 1 No. 2 No. 3 SPIB
Eastern Hemlock, Tamarack No. 1 No. 2 No. 3 NELMA, NHPMA
Aspen-Alder No. 1 No. 2 No. 3 NELMA, NHPMA, WWPA, NLGA
Balsam Fir, Eastern No. 1 No. 2 No. 3 NELMA, NHPMA, NLGA
Spruce
Engelmann Spruce No. 1 No. 2 No. 3 WWPA
Sitka Spruce No. 1 No. 2 No. 3 WCLIB, NLGA
Spruce, Pine, Fir No. 1 No. 2 No. 3 NLGA
Redwood No. 1 open grain, se- No. 2 open grain, con- No. 3 open grain, mer- RIS
lect/select heart struction common/ chantable
construction heart
Northern White Cedar No. 1 No. 2 No. 3 NELMA, NLGA
Alpine Fir No. 1 No. 2 No. 3 WWPA, NLGA
All hardwoods No. 1 dimension No. 1 dimension No. 2 dimension NHLA, SHLMA
A
For identification of agencies, refer to Appendix X2.
TABLE 7 Lumber for Large Posts (5 in. and Thicker and 5 in. and Wider)
A
Species Architectural Class I Architectural Class II Architectural Class III Grade Rule Writing Agencies
Western Red Cedar select quality utility ICA
Western Cedars (Incense select structural No. 1 No. 2 WWPA
& Red) select structural No. 1 structural standard WCLIB, NLGA
Cypress 1 common 2 common 3 common SCMA, NHLA
Douglas Fir-Larch select structural No. 1 structural standard WCLIB, NLGA
Douglas Fir-Larch select structural No. 1 No. 2 WWPA
Hemlock-Fir select structural No. 1 structural standard WCLIB, NLGA
Hemlock-Fir select structural No. 1 No. 2 WWPA
Western Pines select structural No. 1 No. 2 WWPA
Western Pines select structural No. 1 standard NLGA
Eastern White Pine select structural No. 1 No. 2 NELMA, NHPMA
Eastern White Pine select structural No. 1 standard NLGA
Northern Pines select structural No. 1 standard NLGA
Northern Pines select structural No. 1 No. 2 NHPMA
Northern Pines select structural No. 1 No. 2 NELMA
Southern Pine No. 1 dense stress or No. 1 stress rated or No. 2 stress-rated SPIB
dense structural “65” No. 1 timber or No. 2 timber
Eastern Hemlock, select structural No. 1 No. 2 NELMA
Tamarack select structural No. 1 No. 2 NHPMA
Aspen-Alder select structural No. 1 No. 2 NELMA, NHPMA, WWPA
Aspen-Alder select structural No. 1 standard NLGA
Balsam Fir, Eastern select structural No. 1 No. 2 NHPMA, NELMA
Spruce select structural No. 1 standard NLGA
Engelmann Spruce select structural No. 1 No. 2 WWPA
Sitka Spruce select structural No. 1 standard WCLIB, NLGA
Spruce, Pine, Fir select structural No. 1 standard NLGA
Redwood select, select heart or construction common, con- merchantable, No. RIS
select structural struction heart, or 2 open grain
open grain No. 1 open grain
All hardwoods No. 1 dimension No. 1 dimension No. 2 dimension NHLA, SHLMA
A
For identification of agencies, refer to Appendix X2.
wane up to one half the thickness and one third the width for 6.1.2 Architectural Class II, Sawn Posts and Rails—This
one fourth of the length. classificationprovideshighstrengthinafence,whileproviding
F537−01 (2019)
a rustic appearance. Allowable growth characteristics and 6.2 Quality Standards for Split Posts and Rails—Split posts
limiting provisions are described in 6.1.2.1 through 6.1.2.10. and rails shall be graded on the basis of strength and appear-
ance. Tolerances for dimensional variation are also provided
6.1.2.1 Stain and other rustic colorations due to normal
since it is impossible for each post or rail to be exactly alike
weathering or seasoning not limited.
due to its hand-crafted method of manufacture; therefore the
6.1.2.2 Seasoning checks not limited except through checks
dimensions are average and approximate within tolerances
at end limited as splits; allowable splits equivalent in length to
shown.
1 ⁄2times the width of the piece.
6.2.1 A − ⁄2-in. tolerance in girth shall be allowed for
6.1.2.3 Knots, unsound or not firmly fixed approximately
variation in the finished product.
one third the face width.
6.2.2 All longitudinal shaping shall be developed by split-
6.1.2.4 Holes,knotholes,orholesfromanycause,approxi-
ting with axe, froe, wedge, or machine. Cut, torn, or rough
mately 1 in. or equivalent smaller for each 2 ft of length.
grain shall not be classified as defects.
6.1.2.5 Skips, hit and miss.
6.2.3 Knots shall not exceed one half of the narrowest
6.1.2.6 Small spots or streaks of unsound wood, or peck,
dimension in size.
equal to one sixth the width permitted.
6.2.4 Spiralgrainshallnotexceedaone-quartertwistwithin
6.1.2.7 Light shake permitted; through shakes, in 2 through
the length of the piece.
4-in. material, up to 2 ft long permitted away from ends. If
6.2.5 Kinks, bends, crooks, or sweep shall not be greater
through at edges or ends, limited as splits.
than the equivalent of the narrowest dimension, measured as a
6.1.2.8 Slope of grain, not to exceed 1-in. deviation in 8 in.
deviation from a straight line drawn along the center from end
of length.
to end.
6.1.2.9 No spike knot or other growth characteristic shall
6.2.6 No outer bark, sap rot, char, or unsightly discolor-
displace more than one third of a cross-sectional area.
ationsshallbepermitted.Limitedheartrotorpeckinstreaksor
6.1.2.10 Wane, one third of any face; except, that an
pockets shall be permitted. Rustic colorations due to normal
occasional piece may have wane up to two thirds the thickness
weathering and seasoning shall be permitted.
and one half the width for one fourth the length.
6.2.7 Scars,wounds,orsplitsshallnotexceedonefourththe
6.1.3 Architectural Class III, Sawn Posts and Rails—The
depth of the member at the area affected.
mostrusticofallclassificationsbutsuitableandevendesirable
6.3 Quality Standards for Round and Half-Round Posts and
for many wood fence designs. Allowable growth characteris-
Rails—These posts and rails shall be graded on the basis of
tics and limiting provisions are described in 6.1.3.1 through
strength and appearance. Tolerances for diameter variation are
6.1.3.10.
also provided since it is impossible for each natural round post
6.1.3.1 Stained wood permitted.
or round and half-round rails to be exactly alike; therefore,
6.1.3.2 Seasoningchecksnotlimited,exceptthroughchecks
diameters are average and approximate within the tolerances
at end limited as splits; allowable splits equivalent in length to
shown.
twice the width of the piece, but in no case may exceed one
1 1
6.3.1 A − ⁄4-in. or a + ⁄2-in. variation in the nominal small-
sixth of the length.
end diameter shall be allowed.
6.1.3.3 Knots, unsound or not firmly fixed not larger than
6.3.2 Natural taper shall be permitted.
one half the face width.
6.3.3 Knots or limbs shall be trimmed flush and shall be
6.1.3.4 Holes, knot holes, or holes from any cause, not
limited to a maximum of a 50% displacement within any 6 in.
larger than one third of the face width.
of length.
6.1.3.5 Skips, hit or miss up to ⁄8-in. scant.
6.3.4 Kinks, bends, or crook shall be limited to an amount
6.1.3.6 Unsound wood, honeycomb, or peck permitted in
equivalent in inches to half the average diameter, measured as
spots or streaks but shall not displace more than one third of a
a deviation from a straight line drawn along the center from
cross-sectional area. end to end.
6.1.3.7 Mediumshakepermitted;occasionalthroughshakes 6.3.5 No end rot, saw cut, or major defect shall be permit-
permitted when tight and nearly parallel to edges, and limited ted. No outer bark shall be permitted, except for small spots or
in length as splits, measured on the through side. streakslimitedtoamaximumof10%ofthetotalsurfacearea.
Rustic colorations due to normal weathering and seasoning
6.1.3.8 Slopeofgrain,nottoexceeda1-in.deviationin4in.
shall be permitted.
of length.
6.3.6 Seasoning checks or cracks are normal characteristics
6.1.3.9 No spike knot or other growth characteristic, singu-
and shall be limited to one half the diameter.
larly or in combination, shall displace more than one half of a
6.3.7 Length of round posts may be 62 in. Length of rails
cross-sectional area.
may be 61 in.
6.1.3.10 Wane, one half of any face; except that an occa-
sional piece may have wane up to two thirds the thickness for
6.4 Quality Classification of Sawn Fence Boards—The
one fourth the length.
following quality classifications of sawn lumber fence boards
6.1.4 DefinitionsofGrowthCharacteristics—Fordefinitions may be achieved by ripping or cross-cutting ordinary commer-
relating to allowable growth characteristics and limiting pro- cial grades of lumber to meet the requirements as listed.
visionsasallowedin6.1.1through6.1.3,refertoAppendixX1 Compliance can also be achieved by using the minimum
of this specification. commercialgradesoflumberwhichareacceptablealternatives
F537−01 (2019)
and in reasonable accordance with these architectural quality 6.4.3.2 Large seasoning checks permitted.
classifications. Tables 4-7 relate commercial lumber grades by
6.4.3.3 Splits, approximately one fourth the length.
size and use categories to the following fence industry
6.4.3.4 Knots, unsound or not firmly fixed up to approxi-
component-part quality classifications:
mately one half the face width.
6.4.1 Architectural Class I, Sawn Fence Boards—This clas- 1
6.4.3.5 Skips, hit or miss up to ⁄8-in. scant.
sification provides first-rate fence boards of high strength and
6.4.3.6 Pin holes or small holes not limited.
appearance quality. In addition to disallowing such through-
6.4.3.7 Medium through shake permitted.
defects as knot holes, other allowable growth characteristics
6.4.3.8 Spike knots, or other growth characteristics, shall
and limiting provisions are described in 6.4.1.1 through
not displace more than approximately one half of a cross-
6.4.1.9.
sectional area.
6.4.1.1 Light stain allowed; medium stain allowed on occa-
6.4.3.9 Wane, approximately one half the thickness and one
sional pieces if otherwise superior quality.
third the width except heavy wane permitted on back. When
6.4.1.2 Small seasoning checks permitted, with an occa-
through face, limited as holes.
sional medium check not through.
6.4.3.10 Unsound wood, honeycomb, or peck permitted in
6.4.1.3 Short splits, limited to one on each end.
spots or streaks over one third the surface area, but not
6.4.1.4 Knots, sound and tight, approximately one third the
displacing more than approximately one half of a cross-
face width.
sectional area.
6.4.1.5 Skips, hit and miss.
6.4.3.11 Holes, knot holes, or holes from any cause, not
6.4.1.6 Scattered pin holes.
largerthanapproximatelyonethirdthefacewidth.Knotholes,
6.4.1.7 Shake, fine.
or loose knots, or both of maximum size are limited to one for
6.4.1.8 Spike knots, approximately one half the face width
each 4 ft of length, or equivalent smaller.
or equivalent; but no spike knot or other growth characteristic
6.4.4 DefinitionsofGrowthCharacteristics—Fordefinitions
shall displace more than one third of a cross-sectional area.
related to allowable growth characteristics and limitations
6.4.1.9 Wane, not permitted.
described within 6.4.1 through 6.4.3, refer to Appendix X1.
6.4.2 Architectural Class II, Sawn Fence Boards—This
classification provides good strength and appearance qualities,
6.5 Quality Standards for Machined or Hand-Split
while allowing occasional through-defects and offering a
Pickets—These pickets are available in two quality levels,
decidedly more rustic look. Allowable growth characteristics
Architectural Class I and II; both will provide more than
and limiting provisions are described in 6.4.2.1 through
adequate performance while offering distinctly different ap-
6.4.2.11.
pearance characteristics. Faces shall have 100% longitudinal
6.4.2.1 Medium stain allowed; heavy stain allowed on
shaping by splitting with axe, froe, wedge, or machine.
occasional pieces if otherwise superior quality.
6.5.1 Class I—Allowable growth characteristics and limit-
6.4.2.2 Medium seasoning checks permitted.
ing provisions are described in 6.5.1.1 through 6.5.1.6.
6.4.2.3 Short splits permitted, or one tight medium split.
6.5.1.1 Pickets shall be free of rot and bark with one clear
6.4.2.4 Knots, sound and tight up to one half the face width
split face. They may have saw marks on back.
butnotover4 ⁄2in.indiameterorequivalent;knotsunsoundor
6.5.1.2 Pickets shall have straight and parallel edges full
not firmly fixed limited to approximately one third the face
width within a 6 ⁄16-in. tolerance.
width but not over 2 ⁄2in. in diameter or equivalent.
6.5.1.3 Pickets shall be split ⁄16in. thick; split end or top
6.4.2.5 Skips, hit or miss.
shall have a minimum thickness of ⁄16in.; minimum thickness
6.4.2.6 Pin holes not limited.
at butt shall be not less than ⁄16in. at one point or one edge,
6.4.2.7 Shake, light. Through shakes limited to one fourth
average minimum ⁄16in.; maximum thickness at any point not
the length.
to exceed 1 ⁄8in., including dimension at spike knot.
6.4.2.8 Spike knots, approximately three fourths of face
6.5.1.4 Pickets shall be square and trimmed to a length
width; but, no spike knot or other growth characteristic shall
tolerance of ⁄2in. plus or minus.
displace more than one half of a cross-sectional area.
6.5.1.5 Twist and knot curls shall not exceed ⁄2in.; further,
6.4.2.9 Wane, one half of the thickness, one third of the
two pickets standing side by side shall not show a hole or
width.
noticeable gap through, when viewed from a distance of
6.4.2.10 Small spots or streaks of unsound wood, or peck,
approximately 10 ft.
equaltoonesixththewidthandnotmorethanoneeighthofthe
6.5.1.6 A6-in.boworsweepintheflatsurfacethatwillpull
area.
out by bundling or nailing is allowed.
6.4.2.11 Holes, knot holes, or holes from any cause, ap-
6.5.2 Class II—Allowable growth characteristics and limit-
proximately 1 in. or equivalent for each 3 ft of length.
ing provisions are described in 6.5.2.1 through 6.5.2.6.
6.4.3 Architectural Class III, Sawn Fence Boards—The
6.5.2.1 Rot spots or streaks of bark not to exceed one third
mostrusticofallfenceboardclassificationsbuthighlysuitable
of the edge thickness.
and even desirable for many wood fence designs. Allowable
6.5.2.2 Small knots or holes not to exceed ⁄2in. in face.
growth characteristics and limiting provisions are described in
6.4.3.1 through 6.4.3.11.
6.5.2.3 Curved edges or edge sweep not to exceed ⁄4in.;
6.4.3.1 Heavy stain permitted. width tolerance may be 6 ⁄8in.
F537−01 (2019)
6.5.2.4 Thickness on split end allowed to be ⁄32in., mini- 6.7.5 No loose knots, rot, or holes-through shall be permit-
mum; allowable butt thickness, ⁄8in., minimum; maximum ted.
thickness not to exceed 1 ⁄2in. 6.7.6 Noouterbarkshallbepermitted,exceptforoccasional
6.5.2.5 Length tolerance permitted is 6 ⁄4in. very small spots or streaks, the combined area of which shall
6.5.2.6 Twist and knot curls allowed. not exceed 10% of the total surface.
6.7.7 The length
...