InfraLensInfraLens
IS CodesIRCToolsSORHandbookQA/QCPMCFormatsCPHEEOMapsProjectsDCRRulesAbout Join Channel
Join
IS CodesIRCToolsSORHandbookQA/QCPMCFormatsCPHEEOMapsProjectsDCRDesign RulesBIMAbout Join WhatsApp Channel
InfraLensInfraLens
IS CodesIRCToolsSORHandbookQA/QCPMCFormatsCPHEEOMapsProjectsDCRRulesAbout Join Channel
Join
IS CodesIRCToolsSORHandbookQA/QCPMCFormatsCPHEEOMapsProjectsDCRDesign RulesBIMAbout Join WhatsApp Channel

IS 3386 : 1979wooden fence posts

PDFGoogleCompareBIS Portal
Link points to Internet Archive / others. Not hosted by InfraLens. Details
BS 1722-7 · AWPA U1 · ASTM F537-01(2017)
CurrentRareSpecificationMaterials Science · Timber and Timber Stores
PDFGoogleCompareBIS Portal
Link points to Internet Archive / others. Not hosted by InfraLens. Details
OverviewValues4InternationalTablesFAQ3Related

IS 3386:1979 is the Indian Standard (BIS) for wooden fence posts. This standard lays down the specifications for wooden fence posts, covering the suitable timber species, dimensions, dimensional tolerances, permissible natural defects, and the necessary preservative treatments for outdoor durability.

wooden fence posts

Overview

Status
Current
Usage level
Rare
Domain
Materials Science — Timber and Timber Stores
Type
Specification
International equivalents
BS 1722-7:2006 · BSI (British Standards Institution), United KingdomAWPA U1-21 · AWPA (American Wood Protection Association), USAASTM F537-01(2017) · ASTM International, USAAS/NZS 1604.1:2021 · Standards Australia / Standards New Zealand
Typically used with
IS 399IS 401IS 1150
Also on InfraLens for IS 3386
4Key values1Tables3FAQs
Practical Notes
! Fence posts are constantly in contact with soil and moisture; it is critical to ensure preservative treatment strictly complies with IS 401 to prevent early failure.
! Sapwood must be fully penetrated by preservatives, as it is non-durable and highly susceptible to decay and termites regardless of the timber species.
! Avoid using posts with large knots, severe cross-grain, or splits near the intended ground line where bending stress and decay risk are the highest.
Frequently referenced clauses
Cl. 4Species of TimberCl. 5Dimensions and TolerancesCl. 6Prohibited and Permissible DefectsCl. 7Preservative Treatment
Pulled from IS 3386:1979. Browse the full clause & table index below in Tables & Referenced Sections.
timberwoodpreservatives

International Equivalents

Similar International Standards
BS 1722-7:2006BSI (British Standards Institution), United Kingdom
HighCurrent
Fences - Part 7: Specification for wooden post and rail fences
Directly specifies materials, dimensions, and construction for wooden post and rail fences.
AWPA U1-21AWPA (American Wood Protection Association), USA
MediumCurrent
Use Category System: User Specification for Treated Wood
Specifies the required preservative treatment for wood in ground contact (Use Category 4A), a key component of any fence post standard.
ASTM F537-01(2017)ASTM International, USA
MediumCurrent
Standard Specification for Design, Fabrication, and Installation of Fences Constructed of Wood and Related Materials
Broader scope covering the entire fence system's design and installation, including requirements for posts as a component.
AS/NZS 1604.1:2021Standards Australia / Standards New Zealand
MediumCurrent
Specification for preservative treatment - Part 1: Sawn and round timber
Focuses entirely on the preservative treatment process for timber, referenced by Australian fence standards.
Key Differences
≠IS 3386 specifies a list of suitable Indian timber species (e.g., Sal, Teak, Deodar), whereas international standards list species common to their respective regions (e.g., European Redwood/Whitewood in BS 1722-7, Southern Pine in the US).
≠IS 3386 mandates wood preservation according to IS 401, an Indian code. In contrast, BS 1722-7 refers to BS 8417 (based on EN 335 Use Classes), and US practices refer to AWPA U1 Use Categories, which use different classification systems and may approve different chemical preservatives.
≠IS 3386 provides specific metric dimensions and a limited set of cross-sectional shapes (round, square, half-round). US standards often use imperial units, and other standards like BS 1722-7 define post dimensions in relation to the overall fence height rather than a standalone list.
≠IS 3386 does not explicitly specify a maximum moisture content for posts prior to treatment, although this may be covered in the referenced IS 401. BS 1722-7 explicitly requires timber to have a moisture content not exceeding 28% before preservation treatment.
Key Similarities
≈All standards recognize the critical need for durability and mandate chemical preservative treatment for wooden posts intended for in-ground contact.
≈There is a common approach to controlling material quality by placing limits on natural defects such as large knots, splits, decay, and insect attack that could compromise the post's strength and service life.
≈The principle of shaping the top of the post (e.g., sloped, weathered, domed) to shed water and prevent moisture ingress is a common requirement to enhance longevity.
≈All standards define a set of minimum dimensions for the cross-section and length of posts, ensuring they provide adequate structural support for a fence of a given height.
Parameter Comparison
ParameterIS ValueInternationalSource
Primary Preservation Standard ReferenceIS 401: Code of practice for preservation of timberBS 8417: Preservation of wood. Code of practiceBS 1722-7:2006
Ground Contact Use ClassificationDescribes hazards but doesn't use a numeric class system.Use Class 4 (UC4)BS 8417 / EN 335
Timber Species ExampleSal (Shorea robusta), Teak (Tectona grandis), Deodar (Cedrus deodara)European redwood/whitewood (Pinus sylvestris/Picea abies), Douglas fir, LarchBS 1722-7:2006
Standard Post Lengths1.5 m, 1.8 m, 2.1 m, 2.4 m1.65 m (for 1.05m fence), 1.8 m (for 1.2m fence)BS 1722-7:2006
Knot Size LimitationPermitted knots shall not have a diameter exceeding one-third of the width of the face.Sound knots shall not have a diameter greater than one-third of the width of the face on which they occur.BS 1722-7:2006
Post Top FinishSloped on two or four sides from the centre.Weathered (two-way or four-way), rounded, domed, or pointed.BS 1722-7:2006
Minimum Top Diameter (Round Posts)100 mm for 1.5 m length; 125 mm for 2.4 m length75 mm for intermediate posts; 125 mm for straining postsBS 1722-7:2006
⚠ Verify details from original standards before use

Key Values4

Quick Reference Values
Standard length range1.5 m to 3.0 m
Minimum diameter of round posts80 mm
Tolerance on length± 20 mm
Tolerance on diameter or width± 5 mm

Tables & Referenced Sections

Key Tables
Table 1 - Standard Dimensions of Wooden Fence Posts
Key Clauses
Clause 4 - Species of Timber
Clause 5 - Dimensions and Tolerances
Clause 6 - Prohibited and Permissible Defects
Clause 7 - Preservative Treatment

Related Resources on InfraLens

Cross-Referenced Codes
IS 399:1966Classification of Commercial Timbers and Thei...
→
IS 401:2001Code of Practice for Preservation of Timber
→
IS 1150:2000Trade names and abbreviated symbols for timbe...
→

Frequently Asked Questions3

What types of timber can be used for fence posts?+
Species must be selected based on natural durability or their treatability, as classified in IS 399.
Is preservative treatment mandatory for all wooden posts?+
It is heavily recommended, and strictly mandatory for species that do not possess high natural durability against soil and ground contact (as per IS 401).
Are there limits on natural timber defects for fence posts?+
Yes, defects like active borer holes and severe fungal decay are completely prohibited, while knots and splits are allowed only within specific dimensional limits depending on the post size.

QA/QC Inspection Templates

📋
QA/QC templates coming soon for this code.
Browse all 300 templates →