"Richard" wrote in message
om...
Hi

Im just about to start bricking up a doorway which will be a support
for an RSJ after I knock some of the existing wall through to form an
arch. I have been told by the structural enginner that I need to fully
bond the new brickwork with the old by toothing it in. Can anybody
give me some advice on how I go about doing this, do I remove every
second course and lay the new brick into the gap?

Also whats the best way to make sure I get a straight line, should I
use a plumb line or not bother due to the gap being so small?

Also what tool should I use to cut the bricks, I was planning on
hiring an electric cutter of some kind.

Thanks!

Richard

Why can't you use a mechanical fixing i.e. screwed on ties, wall starter, or
helical rods? These would hold the new work just as well.

The problem with toothing is that you can crack the toothed bricks very
easily when cutting the alternate courses. These cracks may be not be
visible on the surface but will crack further later. Also it can be very
hard to ensure the joints are full when you bond the new work, and so the
toothed brick remains unsupported. These can defeat the intended load
spreading of the bond.

Toothing tends to be frowned upon as a reliable bonding method - unless the
work is monitored and properly done.

However, if the work needs to be bonded as it will be seen, then cut out
with a disk cutter and avoid hammering, then make sure the joints are full
or pack with slate.

You don't follow a plumbline, but follow the bond of the existing wall. This
may mean spacing or cutting the new bricks to fit. If you mean horizontal
line, then you use a string line stretched across the opening for each
course.

dg