[mumofstig]

My neighbour has put up that 3ft bamboo cane type fencing on skinny posts, as the boundary fence
I want to put up trellis above the height of his fence to grow climbers and screen my sitting area. it'll only be 3ft trellis but it will be up at the top of 6 ft posts.

Now, my question.........will I still have to use the thick standard fenceposts (on metposts?) to fix it to or can I get away with something thinner?

When I've done this in the past I've just fixed thin timber to the posts already there, but in this situation my posts have to be free standing......his were just banged in with a hammer

[8doubles]

I think you still need at least 3"x3" posts , just think of your trellis and plants as a sail when the wind gets up you need a stout mast.

[JayG]

How long a run of trellis are you planning on having in between posts Mum?

You would probably get away with 2" posts and metposts if the distance was less than about 5', but having to add an extra 2" post just to avoid using 3" posts isn't cost effective (only about 50p difference for the Metposts (in B&Q) although 3" posts are considerably more expensive than 2")

It's not an exact science; partly depends on how windy the site is and to some extent how light or heavy your soil is!

(If you do use Metposts don't do what I did the other day and use a post offcut as a driving tool to protect the Metpost while you bash it in; I cut it too short and it took an hour and a half to chisel/drill it back out!!) 

[mumofstig]

I will use 6ft trellis panels, so it looks like it's the 3" x 3" for me thanks!

(If you do use Metposts don't do what I did the other day and use a post offcut as a driving tool to protect the Metpost while you bash it in; I cut it too short and it took an hour and a half to chisel/drill it back out!!)