Extending a fencepost

[imamartian]

Hi,

I need to extend a 3' fencepost to 6'. Any ideas?

I don't want to use a metpost extender, so was thinking of the best joint to use....

Half-lap - easy to do, glued and screwed
Or similar but like a mortice and tenon.. so the top post has timber either side of the tenon cut in the existing post..

Damn this is difficult to describe in words lol

 

[JohnD]

it will not be very strong

what do you want to fix to it?

How difficult will it be to dig it and and fix a new one when you get fed up with the extended one breaking?

 

[Symptoms]

Either will do, but use a decent glue (polyurethane), bolts (not screws) to hold together (nuts can sit in counterbores so are below surface).

 

[big-all]

what exactly do you want to extend the post for!!!!!

if its for 6ft panels then its not a good idea as it will blow over in the first strong wind

you will be more than doubeling the load on the post [ somwhere about 3 times the load with leverage] so it will be greatly weaknd

 

[2scoops0406]

Do it properly, dig out the old post and replace with a new 3m post with 1m buried in the ground. Use 100mm wide posts as well.

 

[imamartian]

Thanks for the comments...

We are doing a charity "makeover" as an iniative at work.... the garden we are doing is a paved area, and has two 3" posts, but we want to make them 6" and put two 6" trellis panels between them (so wind shouldn't be so much of a problem.)..

Our budget (and time) is limited, so we can't really justify digging up and replacing the posts.

If i glue and screw, will my 'mortice and tenon' solution work?

Thanks

 

[big-all]

your mortice and tennon is more if a finger join
a mortice is normaly a fully enclosed opening on 4 sides with entry normaly only on the joining face

half lap if 6inch on 3"post or 8inch on 4" post would be my normal answer for posts mainly under compression
if the structure is cross linked with other parts that are full height in abox type set up will help
but if your talking a straight wall /panel i would half lap at right angles to the wall face is strongest

and glue is a waste of time in this senario as it will give up eventualy even waterproof glue

 

[Symptoms]

Bolts & external polyurethane glue (it doesn't de-grade) inline 1/2 lap joint. Whole job'll take less than an hour.

 

[imamartian]

In my book, it calls it a corner bridle joint... and it coprises a mortice member and a tenon member. I have just turned the joint 90degrees.

Questions are.... do i do quarters and halves, or thirds?
and do i do the joint parallel to the run of trellis (two 8ft panels), or perpendicular ?

Gentlemen, thank-you for you time!