Replacing single gate post, do they have a special name when the mortices are only on one side?

[chazzyB]

Fitted a feather edge timber fence about 10 years ago and always had a problem with the gate post not the hinge side) which had a split down it which opened in the summer and closed up in the winter, it would twist which left the gate sticking and the bolt only sliding easily for most of the year.
Anyway, maybe due to the extra slamming and flexing the post seems to had rotted under the ground, at first only noticed a bit of movement with the gate, not a "collar" of white mould has emerged from the ground up the bottom 4 cm of the post and in recent storm winds there is a lot more movement.
The rest of the fence is sound and I want to replace this one gate post. I seem to remember the gate posts were in a left/right pair with mortices for the arris rail only on one side. What are these called? What do I need to measure to make sure the replacement fits?
Is there a drop in replacement for a half gate post, half mortice in concrete? or it there a better way to replace the post so that it doesn't rot so quickly (I think it should have lived longer than a mere 10 years... is that reasonable??

Any tips for technique holding the remaining (~3m) featheredge and rails in place while removing and replacing the one end post? O do I need to rebuild the whole side?

 

[blup]

They're either intermediate or end posts, morticed accordingly.

Blup

 

[chazzyB]

end post will need to be morticed according left or right end... are mortices a standard distance apart/from top?

 

[blup]

If they’re not you can cut the post to size or vary depth of installation

Blup

 

[chazzyB]

not much use cutting the post to size if the 3 mortices are not standard distance apart.
The existing fence has 3 rails and the mortice slots are 200mm, 790mm and 1380mm when measured from the top.
I'm looking online and none of the suppliers give mortice measurements so that's why I'm asking if they're standard ie 590mm apart and preferably starting 200mm from the top.

 

[morqthana]

Worst case use a plain post and arris rail brackets?

 

[JohnD]

The rotting is a separate issue. Timber that is buried in the ground will always rot. There are steps you can take to slow it.

However, if you put a concrete spur in the ground, it will not rot. You can bolt your existing wooden post to it after cutting off the rotten end, so that the timber is several inches above the ground to prevent damp. Stand it in a pot of timber preservative (not stain) for an hour or overnight for it to soak in.

As for the movement, brace the gateposts together by bolting a lintel between the two tops. Bolts will not loosen like nails or screws. I use stainless. Studding is cheaper than bolts.

 

[morqthana]

I remember, long before it was banned, my dad used to leave the ends of posts soaking in creosote for weeks before sticking them in.

 

[chazzyB]

The rotting is a separate issue. Timber that is buried in the ground will always rot. There are steps you can take to slow it.

However, if you put a concrete spur in the ground, it will not rot. You can bolt your existing wooden post to it after cutting off the rotten end, so that the timber is several inches above the ground to prevent damp. Stand it in a pot of timber preservative (not stain) for an hour or overnight for it to soak in.

As for the movement, brace the gateposts together by bolting a lintel between the two tops. Bolts will not loosen like nails or screws. I use stainless. Studding is cheaper than bolts.

Thanks, I actually got to the same conclusion and will be buying a concrete spur later.
What are the best fixing for the spur to the post? screws or bolts all the way through?

Was thinking putting a bolt through the post to keep the cracks closed and stop the twist.

 

[JohnD]

Bolt all the way through. You can buy m8 x 150mm hex bolts and nuts singly on ebay. Measure the actual size you need.

But they are expensive. You will need D or penny washers.

You will find vendors who will cut stainless studding to length, and it works out cheaper. Gavanised will rust badly

If the nuts are visible or you might brush against them, you can get Dome or Acorn nuts. Grease before asssmbly.

 

[chazzyB]

Bolt all the way through. You can buy m8 x 150mm hex bolts and nuts singly on ebay. Measure the actual size you need.

But they are expensive. You will need D or penny washers.

You will find vendors who will cut stainless studding to length, and it works out cheaper. Gavanised will rust badly

If the nuts are visible or you might brush against them, you can get Dome or Acorn nuts. Grease before asssmbly.

The place I got the spur recommended coach screws M10x180mm 3x @£2each. Pilot hole of 8mm
The post is 100x100 and so is the spur.
I can get a BZP M10x220 coach bolt for £1.82 each.
It's a gate post so 2cm sticking out either is going to catch somebody.
I think I'm going to go for the coach screws. not sure pilot hole needs to be so big. one spec says 5mm softwood and 7.5mm for hard wood

 

[JohnD]

Coach screws are big woodscrews with hex heads.

Coach bolts are bolts that you use with a nut, but they have no hex or slot on the head so you will not be able to tighten them up or undo them later (except on the first day or so when the thread is freshly greased and the timber has not worn). Use hex-headed bolts, or studding with two nuts and washers.

Using a bolt or studding you can cut off any excess after tightening. If you are posh you can cut to size and use a dome nut. If you seriously want to, you can drill a pocket in the post big enough for your washers and tighten with a socket so the nut and stub do not project.

If you have a saw you can buy 8mm BZP studding at the DIY shed.

(but I use and recommend stainless)

M4, M5, M6, M8, M10, M12, M16, M20 A2 STAINLESS STEEL STUDDING BAR CUT LENGTHS | eBay

ALLTHREAD / STUDDING / THREADED BAR. M4, M5, M6, M8, M10, M12, M16, M20. A2 STAINLESS STEEL. OTHER LENGTHS ARE AVAILABLE. A NUT OR OTHER CONNECTOR. 3 LENGTH VARIATIONS LISTED. ALL ENDS ARE CHAMFERED TO RECEIVE.

www.ebay.co.uk

 

[morqthana]

Coach bolts are bolts that you use with a nut, but they have no hex or slot on the head so you will not be able to tighten them up or undo them later (except on the first day or so when the thread is freshly greased and the timber has not worn). Use hex-headed bolts, or studding with two nuts and washers.

Unless of course you want the bolts to be undo-able from one side to stop the ne'er-do-wells from undoing them to gain access.

 

[JohnD]

Washers under the nuts on the other side will enable them to spin without coming off.

Your local petty criminals must be too frail to climb over a gate.