On 18/03/2013 22:21, ss wrote:
On 18/03/2013 15:51, RobertL wrote:
On Sunday, 17 March 2013 21:38:47 UTC, imanc wrote:
Hi,

I'm trying to erect a fence over the site of my house's previous back
yard wall.



it's a victorian terrace and most of the walls on the row have been
removed so people can park their cars in their back gardens. However
due to having dogs and no car, I need a fence.



1) Getting through the brick foundation is proving extremely challenging
using a cold chisel and standard hammer drill. I've managed to remove
two bricks from one of the holes, and have produced a ~7inch hole.

If the bricks are so well fixed down why not bolt the posts to the
brick using brackets?


Robert


Instead of working on a theory (not being funny) set one post as you
have it (a couple of layer of brick removed) let it set for a couple of
weeks and knock F... out of it with a sledge hammer and see what
happens. That would give a good indication if its likely to stay put in
a storm or keel over. Otherwise keep digging or take a chance.
:-)

Whacking the posts with a sledgehammer will show if they are going to
fail, but I rather doubt it would replicate the loads the wind can exert.

Assuming the fence is 6ft tall and given the description of four posts
(i.e three sections) at 4'6" spacing, a fairly modest 60mph wind would
give a wind load on it of around 3/4 of a ton. To survive the 120mph (or
possibly more - the anemometer at Shoreham by Sea failed at that point)
gusts experienced in SE England during the Great Storm, it would need to
withstand around 2.7 tons wind loading.

Colin Bignell