Wall ties are used to tie together the two leaves of a cavity wall, making the wall stronger and able to support more load. The ties must be placed correctly by the bricklayer in accordance with building regulations, with spacing no more than 150mm from openings and 750mm horizontally and 450mm vertically. Proper placement involves pressing ties fully into each wall leaf with any drip pointing downwards in the center of the cavity. Special wall ties are needed when cavity insulation is used to support the insulation at intervals.

1. Cavity Walls
Wall ties in cavity walls

2. Tutor Copy

3. The purpose of wall ties in cavity
walls
A cavity wall consists of two
slender, independent leaves of
brickwork or blockwork. If a load
is exerted to one or both of
these slender walls they may
buckle or collapse under the
load. If the two leaves are tied
together they will virtually be as
strong as a solid wall and they
can support more imposed
loadings.

4. To tie the two walls together,
wall ties are built into the walls
in sufficient numbers and at
strategic positions throughout
the wall area.
The bricklayer is responsible for
building in the wall ties in their
correct positions. Care and
attention must be taken when
building them into position,
because poor workmanship
may lead to damp penetration,
distortion of the wall, cracking
or in some cases, collapse of
the wall.

5. Types of wall ties
There are a number of different shapes and
sizes of wall ties made from galvanised steel,
stainless steel, alloys or polypropylene. They
are manufactured in various lengths to suit
different wall cavity widths.
The type of tie to be used in a particular wall
will be specified by the architect.

6. It is up to the bricklayer to exercise some skill
and common sense when placing the wall
ties.
The ties should be placed in accordance with
the Building Regulations which specifies
where the ties should be placed and spaced
horizontally and vertically namely:
• A distance of 150mm max from the edge
of an opening (BR).
• Vertically spaced every block course or
• Every 4th course if both wall leaves are of
brickwork.
• A distance of 750mm max horizontally
and 450mm vertically.

7. Note:
When placing wall ties, a
good rule of thumb is that
more ties are better than
fewer.

8. Maximum 150mm Maximum 150mm
Maximum 900mm
Maximum 450mm
Wall tie positioning and spacing
At an unbonded
reveal max. spacing
300mm

9. Placing ties correctly
As a guide to placing wall ties effectively the following points of good
workmanship may be of help.
• For strength, all ties must be bedded at least 50mm into each wall leaf.
• The ties must be positioned with any drip in the centre of the cavity, and
pointing downwards.
• Ties should be pressed down into the mortar bed.
• Ties should never be pushed into a joint as they will not be effective in
tying in the two leaves together.
• Ties should be inclined downwards towards the outer leaf, never to the
inner leaf as they may provide a bridge for water.
• Always maintain the gauge of the brickwork and consistency of joint
thickness.
• Ties should never be bent to suit courses.
• Ties must be cleared of mortar droppings which can provide a passage
for water across the cavity.
• Use only specified type of tie.
• Use extra ties around openings if needed.
• Use extra ties at the tops of gable walls.

10. Correct positioning of wall ties

11. Special wall ties
When the cavity is filled with rigid thermal insulation
material such as cavity bats, they are supported at
450mm intervals by special wall ties. These ties
have a device incorporated into
their design to keep the bats
against the inner leaf of the wall.