On Sun, 4 Jul 2010 14:29:26 +0100, "Phil L"
wrote:


The twist is so that whichever way up it gets put in, there's a low point in
the centre for moisture to drip off.
Prior to this, they had just a 'bump', and they were supposed to be laid
with the bottom of the bump at the underside, but dozy bricklayers often put
them in with the bump at the top.

The one in the picture is called a fishtail brick tie, these rust terribly
and push courses apart, usually every 6 courses and often near the upper
parts of the building.
Once they start going, they need isolating and new replacement ties going
in, they are isolated by chipping all around each one (found by metal
detector) and a plastic sleeve containing grease is slid over the end of
each one to prevent further corrosion, new ties are put through the face of
the brick rather than the beds.

Galvanised ones were used after this but they too were shunned in favour of
stainless steel and even plastic ones, which had a short lived popularity in
the early 90's.


The things you learn on this group!

Dave