HANGING YOUR GATES Selecting and installing your gate posts The choice for timber gate posts for most farm type gates is basically limited to a choice of treated softwood, larch (treated or untreated) or oak. Treated (usually pressure tanalised but can include pressure creosoted) softwood posts are ideal for most gate installations and have a good life expectancy. Larch is a little more difficult to readily source today and has the added problem of not remaining straight due to the tensions within the sawn wood. The longevity of larch is good especially if treated. Oak is perhaps better chosen for a more traditional finish and is often suited better to heivier gates. Oak is better if creosote finished which not only increases its life expectancy but enhances the grain for a classier look. Selecting for post size, we recommend 6" x 6" section posts only for 3' and 4' gates. 7" x 7" section posts for 5' - 12' gates, and 8" x 8" section posts for gates over 12' long. Installation of the posts, - we would always recommend installing at least 3'6" in the ground by digging a hole with either a spade or borer but never a digger, this should give a tight vertical sided hole and is crucial to the long term stability of the posts. All the excavated material should be backrammed in to secure the post or for a guarenteed firm finish concrete can be used but never put concrete under the post, the base of the post must be stood on freedraining material.
Positioning New Posts There are basically two ways to hang a gate, - either on the backs of the posts or between the posts. Normally gates should be hung on the backs of the posts this enables you to utilise all available adjustments on the hangings to vary the position of the gates in two planes, as well as eliminating any vertical gaps. Some installations however demand that the gates are hung between, so perhaps the gates can swing both ways or you wish to see all of the gate detail. In either case posts must be positioned accurately according to the width of the gate and making allowances for your chosen hangings. Single gate hung on the back of the post,- calculate distance between posts as follows:- General rule of thumb for farm type gates, use square treated timber gate posts between 7" and 8" for gate lenghts between 5' & 15'. To hang a single gate on the back of the posts then take the proposed gate width less 3", Ie. a 12' gate would require 11'9" between the inside faces of the gate posts. For 3 & 4' gates hung on 6" square posts the calculation is proposed gate width less 2". Double leaf gates hung on the backs of the posts, - calculate distance between posts as follows:- Again using the same general post size rules then the calculation is - Proposed combined gate widths less 2" unless the gate heads meet on a rebate and then reduce this calculation by a further 1". Ie. for a double leaf 16' (that would be 8' + 8') then less 2", therefor the gap between the posts would be 15'10" or 15' 9" for rebated gates. Single gate between the posts, - calculate distance between the posts as follows:- Proposed gate width plus 7½" which then allows for standard field gate hangings and mortice latch or spring latch. Ie. for a 10' gate the gap would be 10'7½" Double leaf gates hung between the posts, - calculate distance between the posts as follows:- Proposed combined gate widths plus 9¾" unless the gates meet on a rebate, then reduce this calculation by ¾". Ie. for a double leaf 12' gate the gap would be 12'9¾" or 12'9" if the gates meet on a rebate. Recommended hangings and fastenings. For timber field gates in most situations, - Top of gate, - Galvanised top band, 12" for gates 3' or less 18" for gates 4' - 12' 24" for gates over 12' Bottom of gate, - Galvanised adjustable eye bolt and heel clips for all situations except perhaps a galvanised static short bottom band could be used for gates of 3' or less. Top of post, - Galvanised hook to bolt for all sizes of gates and posts. Bottom of post - Galvanised square hook to bolt with welded washer for all situation other than perhaps a 3' gate or less where a drive in hook will be acceptable. The hook to bolt with welded washer is a very important part of the hinging system being subjected to emense leverage forces, something a hook to drive is unable to cope with. Fastening the gate, - There is a whole plethera of differing gate catches but for a standard field gate hung on the backs of the posts then we always recommend a large auto catch. This not only secures the gate closed but allows you to swing the gate shut and it catches itself, but the most important benefit of this system is that this catch offers support to the gate at its head end when closed, vastly increasing gate life and post life. For a further increase in gate and post life one of these catches can be installed on a remote post in the open position. |
