DRAFT  KENYA STANDARD                 DKS 1608: 2017 
          ICS 79.040; 91.090  
 
  
 
  
 
 
  
Specification for wooden fence posts  
 
 
 
  
 
 
 
 
  
 
 
  
 
  
 No copying of this standard without KEBS permission except as permitted by copyright law   
 
 
 
  
 
 
 
 
 
 
 
  
 
  
 DKS 1608: 2017                  ©KEBS
     
 2 ©KEBS 
 TECHNICAL COMMITTEE REPRESENTATION  
 
The following organizations were represented on the Technical Committee:  
 
1. Marlow Link Timber  
2. KAKUZI 
3. HIGHCHEM  
4. Millennium Trading House Limited 
5. National Environmental Management Authority (NEMA) 
6. Kenya Forestry Research Institute (KEFRI) 
7. Pest Control Products Board (PCPB) 8. University of Eldoret 9. PEMAK 10. Alogo Enterprises 11. COSTEK ALMA 
12.        Kenya Power   
13. Kenya Wood Preservers Association 
14. Muringa holdings 
15 Kenya Bureau of Standards – secretariat
 
 
 
 
  
 
  
 
REVISION OF KENYA STANDARDS 
 In order to keep abreast of progress in industry, Kenya Standards shall be regularly reviewed. Suggestions for 
improvements to published standards, addressed to the Managing Director, Kenya Bureau of Standards, are welcome. 
  
  
 
 
© Kenya Bureau of Standards, 2001 
 
Copyright.  Users are   reminded that by virtue of section 6 of the Copyright Act, Cap. 130 of the Laws of Kenya, copyright sub sists in all 
Kenya Standards and except as provided under section 7 of this Act, no Kenya Standard produced by Kenya Bureau of Standards may  be 
reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in writing from the M anaging 
Director.  
Permission may be conditional on an appropriate royalty payment. 
 Care should be taken to ensure that material used is from the current edition of the standard and that it is updated whenever t he standard is 
amended or revised.  The number and date of the standard should therefore be clearly identified. 
 The use of material in print or in electronic form to be used commercially with or without payment or in commercial contracts i s subject to 
payment of a royalty. 
 
 
 
  
 
  
 
  
 
                                                                             DKS 1608: 2017 
 
 3                         3
  
 
KENYA STANDARD                   DKS 1608: 2017 
                             ICS 79.040;91.090 
 
           
 
 
 
  
 
  
 
Specification for wooden fence posts 
 
  
 
  
 
 
 
 
  
  
 
  
 
  
 
  
 
   
 
KENYA BUREAU OF STANDARDS (KEBS) 
 
Head  Office:  P.O. Box 54974, Nairobi-00200, Tel.: (+254  020) 605490, 602350, Fax: (+254 020)  604031 
E-Mail: info@kebs.org,  Web:http://www.kebs.org   
 
Coast Region    Lake Region         North Rift Region  
P.O. Box 99376, Mombasa-80100  P.O. Box 2949, Kisumu-40100       P.O. Box 2138, Nakuru-20100 Tel.: (+254  041) 229563, 230939/40 Tel.: (+254 057) 23549, 22396       Tel.: (+254 051) 210553, 210555
 
Fax: (+254  041) 229448   Fax: (+254 057) 21814  
 
 DKS 1608: 2017                  ©KEBS
     
 4 ©KEBS 
 P R E F A C E 
 
This Kenya Standard was prepared by the Woodpoles Technical Committee under the guidance of the Building 
and Civil Engineering Industry Standards Committee and it is in accordance with the procedures of the Bureau.  
Wooden fence posts are extensively used for protecting various buildings, gardens and forest plantations. This 
standard is intended to give guidance on the sizes, workmanship and other requirements, and treatment of fence posts for the more common type of fences. It does not cover fence posts of decorative or any special 
nature.  The standard is also intended to ensure satisfactory service to the purchaser and assist the suppliers 
and erection contractors by eliminating avoidable variation in demands. 
 
Species of timber for fence posts shall be available in a round form in their natural state and shall be 
mechanically strong.  
 In the preparation of this standard, reference was made to the following document: 
 
    IS 3316:   Specification for wooden fence posts       
Acknowledgement is hereby made for the assistance derived from this source. 
  
 
  
 
  
 
 
  
 
  
 
  
 
  
 
  
 
 
  
 
  
 
 
  
 
  
 
  
 
                                                                              DKS 1608: 2017 
 
 5                         5
  
KENYA STANDARD 
 
SPECIFICATION FOR WOODEN FENCE POSTS 
  
 
1. SCOPE 
 
 This standard specifies the requirements of wooden fence posts and accompanying rails and guy rods 
for purposes of general use and also covers recommendations on their use under ordinary conditions. 
 
2. DEFINITIONS 
  
 For the purposes of this standard, the following definitions shall apply: 
 
2.1 cleft fence post — Segmental fence post obtained only by splitting.  
 
2.2 curvature (sweep) — Deviation of a pole/member from straightness. 
 
2.3 holes — Cavities caused by worms, insects, birds or mechanical means.  
 
2.4 guy rod — A supporting inclined piece of timber used along with the vertical post particularly at the 
corners of the fence. 
 
2.5 knot — A branch or limb embedded in the tree or timber by natural growth. 
  
2.6 pale fencing — Enclosing or restricting fence.  
 
2.7 prick post — Light fence post between the main posts in a wooden fence used for supporting rails. 
   
2.8 fence rail — Horizontal member in a fence to ensure a predesigned protection which the fence is 
expected to serve.  
 2.9  round timber — Timber in the original round form. 
 2.10 segmental post — A post having approximately a segmental cross-section throughout the length 
obtained by either sawing or splitting a round fence post.                                    
 
2.11 slope of grain — The inclination of the fibres to the longitudinal axis of the pole/member. 
 
2.12 surface crack — A shallow longitudinal separation of the fibres that does not extend beyond a depth of 
10 mm.   
2.13 prophylactic treatment — Protective treatment after debarking by either brushing, spraying or dipping 
in any of the preservative solutions specified in KS 02-94
*. 
 
2.14 morticed fence — A fence in which the joints are formed by fitting a piece of timber into a cavity cut in 
the surface of another piece of timber.  
 
2.15 end split — A split at the end of a log or a piece of timber. 
 
2.16 segmental — A plane figure contained by a right line on a portion of the circumference of a circle. 
 
2.17 scarf  — A joint by which two timbers are connected longitudinally into a continuous piece, the ends 
being halved, notched or cut away so as to fit into each other with mutual overlapping.  
  
2.18 wane — The original underback surface with or without bark on a piece of sawn timber. 
 
  
  
                                                            
*Specification for preservation of timber. DKS 1608: 2017                  ©KEBS
     
 6 ©KEBS 
 3.  SPECIES OF TIMBER 
 
 Any suitable species of timber meeting the requirements of this standard may be used for fencing 
posts. 
  4. PERMISSIBLE DEFECTS 
 
4.1   Surface Cracks — In round and cleft fence posts, surface cracks shall not exceed  10  mm  in  depth, 
3 mm in width, and length not more than one-third the length of the post.  In sawn posts (rectangular or 
segmental surface), cracks are permitted only up to 5 mm in depth, 1 mm in width and up to 100 mm in length.  The number and location of surface cracks shall not impair the usefulness of the post. 
 4.2.1 End Splits — The longest end split in round and cleft fence posts shall not be more than the butt 
diameter at the butt end and not more than half the to p diameter at the top. However, the length of the 
split at both ends shall not exceed 75 mm and the number of end splits shall not exceed four on either 
end. 
 
4.3     Knots — The total knots diameters at any given cross-section shall not be more than half the diameter 
or cross-sectional dimensions of fence posts.  Their number, condition and distribution shall be such as 
not to weaken a post to an extent that makes it unsuitable for use. 
 4.4   Slope of Grain — The slope of grain shall not be steeper than 1 in 10 for round and segmental posts 
and 1 in 15 for sawn posts measured along the axis of the post. 
 4.5   Holes — These shall be well scattered and not concentrated in any area and no hole containing live 
insect infestation shall be permitted. 
 
4.6   Curvatures — A maximum deviation from the longitudinal axis equal to half the diameter or cross-
sectional dimension in the respective plane shall be permitted in any post or guy rod.  
 5.  TYPES AND DIMENSIONS OF FENCE POSTS  5.1 Fence posts shall be of two types given in Table 1. 
 
TABLE 1. TYPES AND DIMENSIONS OF FENCE POSTS 
 
                   All dimensions are in millimetres 
 
 
TYPE  
LENGTH 
  
DIAMETER OF 
ROUND AND 
SEGMENTAL 
POSTS 
  
CROSS SECTION OF 
RECTANGULAR FENCE 
POSTS 
 
 
Width 
  
Thickness 
 
 
1  
Above 2 500  
120 -  200  
100 -200  
50 - 200 
 
 
2  
1 500 – 2 500  
80 - 120  
50 -100  
50 - 100 
 
  
5.2  A tolerance of ± 50 mm in length, ± 5 mm in diameter  of round and segmental posts and in the width of 
rectangular posts shall be permitted.  A tolerance of ± 2 mm in the thickness of these posts shall be permitted. 
 
5.3 Unless otherwise specified, all fence posts shall conform to the dimensions specified in 5.1 and 5.2. 
 
5.4 The lengths shall be measured between the extreme ends of the posts; the diameters and cross-
sectional dimensions shall be measured at the mid-length of the posts. 
 
5.5  The smaller dimension of the post shall  determine the type of the fence post.                                                                             DKS 1608: 2017 
 
 7                         7
 6.  MANUFACTURE 
 6.1 Unless otherwise specified, the bark of the round and the segmental posts shall be completely removed 
and all the branches and protruding portions shall be dressed down to flush with the surface.  The bottom ends (ends of larger diameter) shall be sawn square and the tops shall be either tapered or 
sawn square as required. 
 6.2   The sawn rectangular fence posts shall have uniform cross section throughout the length and shall be 
pointed at the tops, when required, as for pale fencing. 
 6.3    Prick posts shall be of a section equal to that of the rails and of the same length as that of the main 
posts. They may be sawn or cleft and may be tapered. Sometimes they may be pointed at the lower 
end for the purpose of driving into the ground. 
 6.4    All posts and corresponding rails and guy rods, wherever required, shall be suitable for fixing to fences 
as recommended in the Appendix A. 
 
7.  REQUIREMENTS  
 
7.1  All fence posts and guy rods shall be air or kiln seasoned as specified in KS 1011
* to a moisture content 
not more than 18 per cent within a depth of 10 mm from the surface when measured anywhere in the 
middle one-third length of the post, and shall be fit for proper treatment ( see 8). The moisture content 
shall be determined in accordance with the method specified in KS 02-982†. 
 
7.2    The fence posts and guy rods shall be reasonably straight and shall be free from defects other than 
those permissible under 4. 
 
7.3  Rails shall conform to A4 and shall be governed by the appropriate clauses for fence posts. 
 
8.  PRESERVATIVE TREATM ENT AND PAINTING 
 
8.1    Prophylactic Treatment for Protection during Storage — If immediate preservative treatment is not 
possible, the fence posts, after debarking shall be given prophylactic treatment either by brushing, 
spraying or dipping with any of the preservative solutions specified in KS 02-94‡ to avoid infection by 
fungi or insects during transport or storage.  The prophylactic treatment should be given immediately 
after the felling of the trees.  
 
8.2  Preservative Treatment for Long Term Protection in Use  
 
8.2.1  For obtaining a long service life, the fence posts, guy rods and rails shall be treated by pressure 
process, by hot and cold process or sap-displacement method. 
 8.2.2 For timber whose heartwood is durable or whose heartwood is easily treatable, hot and cold process 
using creosote-fuel oil (50:50) mixture or by modified hot and cold process with water-soluble preservatives may be adopted.  The posts, guy rods and rails should, however, be treated by pressure 
process if the facilities for the same are available.  The green timber after careful debarking  may also 
be treated by adopting sap-displacement method using water-soluble preservatives. 
 
8.2.3   For treatment of all timbers whose heartwood is not durable and is not easily treatable irrespective of 
the type of preservative employed, pressure process shall be adopted. 
 
8.2.4  Recommended preservatives and their absorption on penetrated cross section basis shall be as given 
in Table 2. 
 
 
  
                                                           
 
*  Code of Practice for seasoning of timber. 
†  Methods of test for determination of physical and mec hanical properties of wood Part 1. Moisture      
content. 
‡   Specification for preservation of timber. 
 DKS 1608: 2017                  ©KEBS
     
 8 ©KEBS 
 TABLE 2. RECOMMENDED PRESERVATIVES 
 
 
PRESERVATIVE 
 ABSORPTION 
Creosote: fuel oil (50:50) 
 160 kg/m3 
Creosote/LTG : fuel oil mixture 
 160 kg/m3 
Pure creosote/LTG 
 128 kg/m3 
Copper-chrome-arsenic 
compound 
 12 kg/m3 
Copper-chrome-boric-acid  
Compound 
 20 kg/m3 
Acid-cupric-chromate 
compound 
 12 kg/m3 
 
8.3  Fence posts, which are to be painted, shall be treated with water borne preservatives. Painting shall be 
done after the posts have been thoroughly dried. 
 
9. MARKING  
 9.1  Each fence post shall be marked legibly and indelibly with the following information: 
 
(i) Manufacturer's name or trademark; 
(ii) Type of post; 
(iii) Year of preservative treatment;  (iv) Type of preservative; 
(v) Species of wood. 
 
9.2  The butt of each post shall be marked with the type and length for identification of posts. 
 
9.3 Each post may also be marked with the  Kenya Bureau of Standards Certification Mark subject to 
approval by the Bureau.     
 10. SAMPLING 
  
10.1  Lot — In any consignment, all the wooden fence posts of the same type and manufactured under 
similar conditions of production shall be grouped together to constitute a lot. 
 
10.2 The number of fence posts to be selected from the lot as samples for inspection shall depend upon the 
size of the lot and shall be in accordance with Co lumn 1 of Table 3.  The selection shall be done at 
random. 
 
10.3 All the fence posts selected as in 10.2 shall be inspected for visual defects, moisture content, 
dimensions and tolerances, preservative treatment and painting.  Any fence post which fails to satisfy 
the requirements of any one or more characteristics shall be considered as defective. 
 10.4 Criteria for Conformity — The lot shall be considered to be conforming to the requirements of this 
standard if the number of defective fence posts out of those inspected does not exceed the 
corresponding number given in Table 3, Column 3. 
 
  
 
  
                                                                             DKS 1608: 2017 
 
 9                         9
 TABLE 3. SAMPLE SIZE AND CRITERIA FOR CONFORMITY 
 
 
LOT SIZE  
SAMPLE SIZE  
PERMISSIBLE NUMBER 
OF DEFECTIVE FENCE 
POSTS 
 
Up to 100 13 0 
 
101-150 20 1 
 
151-300 32 2 
 
301-500 50 3 
 
501-1 000 80 5 
 
1 001-3 000 125 7 
 
3 001 and 
above  200 10 
 
 
11. ERECTION  
 
 
Erection of posts and rails shall be governed by the recommendations in the appendix and all components of fence shall conform to a pre-designed uniform pattern throughout the fence. 
Preservative treatment and painting shall conform to the requirements specified in 8. 
 
The corner posts and some intermediate posts shall be braced. The bracing shall be inclined and should be at a point within the top third of the length of the corner or intermediate post measured above 
the ground level. 
 The size of the bracing and guy rods shall be approximately the same size as the fence post.  
 
12. Banding and nail plates  
For fence posts whose top diameter does not exceed 5" , splitting is insignificant , if the posts were off 
cuts from power transmission poles. But for fence posts whose diameter class is 5"- 6" (and above), all 
factors remaining constant, binding the tops with either anti- split plates or metal banding straps, as per the description in KS 516. 
  
 
A P P E N D I X   A 
 
RECOMMENDATIONS FOR ERECTION OF FENCE POSTS  
 
 
A1. FOUNDATION  
 
A1.1  All fence posts shall be erected so that at least 400 mm of the butt is firmly gripped in the ground. 
 
A1.2  The holes in the ground shall be as small as practicable to allow for refilling with earth which shall be 
well rammed.  The diameter of the hole shall be at least 100 mm greater than the diameter of the post. 
 
A1.3  When the posts are set in concrete, the concrete shall be completely set with posts gripped in it. The 
top of the concrete shall be sloped away from the post in all directions to facilitate drainage. The 
concrete used shall be grade 20 (1:2:4) 
 A2.  SPACING  DKS 1608: 2017                  ©KEBS
     
 10 ©KEBS 
   
 The spacing of the posts shall be such as to provide the required degree of protection adequately.  A 
maximum distance of 3 m  for morticed fences, and 2 m  for nailed fences is recommended. 
 
 
 
A3.   CONNECTING MATERIAL  
  
 The posts shall be linked by barbed wire or wooden rails or any other type of suitable connecting 
material. For long-term protection, all nails and other iron material shall be galvanized. 
 
A4.   RAILS 
  
 When wooden rails are used, these may be wane-free, rectangular or sawn or cleft segmental poles of 
not less than 80 mm in diameter at thinner end. A convenient recommended size for rectangular sawn 
rail is 75 mm x 38 mm.  The rails shall be sawn straight, so that when fixed, the centre line of the rail 
shall not deviate at any point more than 50 mm from the ground within the length between any two adjacent posts. The segmental posts may also include the natural curve of the round pole provided 
such curvature appears only once and in one plane only. 
 
A5.  MORTICED FENCE  
 
A5.1  In a morticed fence, one prick post shall be supplied for each bay and driven into the ground to a depth 
of 400 mm. 
 
A5.2  In morticed fences, wooden rails shall fit into the mortices in the posts and shall be nailed to each prick 
post with two plain head wire nails of 100 mm length at each inter-section and the ends of nails shall be clinched downwards. 
 
A5.3 Joints in rails of morticed fences shall be scarfed, the length of the scarf being 150 mm. 
 
A6.  JOINTS  
   In nailed fences, rails shall be butt-jointed on the centre line of such posts. The joints shall be staggered 
so that alternate joints occur in one post. The rails shall be nailed to the posts with two nails at each 
end and two nails at the centre and one nail on other posts.  The nails shall be 100 mm in length and 
clinched downwards. 
 A7.  SPACING OF RAILS  
  
 The number of rails running parallel to each other in any fence shall depend upon the protection 
expected of the fence and their spacing shall be  equal  between  the bottom post rail and a point 100 
mm from the top of the post. 
 
A8.   LEVEL OF FENCE  
 
When finally erected, the level of the fence shall follow approximately the profile of the ground and shall 
conform truly to the design set out by the indentor.