Securing a seat to tarmac....

[imamartian]

i want to make a seat to go around a mature tree. The ground around the tree is old tarmac and uneven. My plan is to make a simple hexagonal, decking board, bench seat to go round the tree, and bolt this to treated posts of varying lengths (to sort the unevenesss). But my quest is, how do i support the posts on, or in, or through the tarmac?

My first thought was to drill small holes in the tarmac nad then hammer in metpost spikes.....

any other thoughts?

 

[big-all]

surely the seat will be fairly weighty and substantial!!
can you not use 8mm stainless steel/galvinised rod
a 10mm hole filled with no nails and rely on the weight to keep it in place
try and seperate the feet from the ground with slate topped with felt or simmilar barrier to protect the end grain off the wood from the ground

 

[Thermo]

the weight should be enough i would have thought. theres nothing under teh tarmac to drill into to give a decent fixing. the other option would be small pockets cut out of the tarmac, backfilled with concrete and threaded rod cast into it to bolt on to

 

[ColJack]

dig the tarmac out to the footprint of your seat.. then concrete the posts in if you fear the seat will be nicked..
the tree is obvoiously causing the tarmac to heave and I'm sure it will appreciate a bit more soil that can get wet to provide it with water..

 

[imamartian]

thank-you very much gents... bit unsure about digging out and concreting posts in as there's bound to be roots down there... although threaded contreted in seems a good idea.

The bench will be weighty, but the ground is so uneven that the slightest knock will give it a wobble... and from there on in, it will be problematic.

And i'm not really bothered about it getting nicked.

And the slate and felt feet is a great idea.