Cavity Wall TiesCavity Wall Ties

There are a variety of wall ties on the market. Most are made from steel, either galvanised or stainless. Some ties are made from plastic (right). All ties incorporate drips to prevent water crossing the cavity. They are available in various lengths to suit different cavity widths.

Spacing of Wall TiesSpacing of Wall Ties

• The spacing of the ties The spacing of the ties should be 900mm should be 900mm horizontally and 450mm horizontally and 450mm vertically. vertically.

• Additional ties are Additional ties are required within 225mm required within 225mm (Code of Practice - B. Regs (Code of Practice - B. Regs requires 150mm but will requires 150mm but will soon be altered) of the soon be altered) of the jambs of any openings. jambs of any openings.

• They should be no more They should be no more than 300mm apart than 300mm apart vertically which effectively vertically which effectively means every three means every three courses of brickwork (1 courses of brickwork (1 course of blockwork). course of blockwork). Extra ties may be required Extra ties may be required to support insulation to support insulation boards.  boards. 

Ties spacing’s for gablesTies spacing’s for gables

The ties should ideally slope slightly outwards to help prevent The ties should ideally slope slightly outwards to help prevent water reaching the inner leaf. Where partial cavity fill is water reaching the inner leaf. Where partial cavity fill is specified a special tie incorporating a large plastic retaining specified a special tie incorporating a large plastic retaining washer should be used.washer should be used.

The ties should ideally slope slightly outwards to help prevent The ties should ideally slope slightly outwards to help prevent water reaching the inner leaf. water reaching the inner leaf. Where partial cavity fill is specified a special tie incorporating a Where partial cavity fill is specified a special tie incorporating a large plastic retaining washer should be used. large plastic retaining washer should be used.

It is preferable to leave a cavity of 50mm although 25mm may be It is preferable to leave a cavity of 50mm although 25mm may be

acceptable in sheltered situations.acceptable in sheltered situations.

Remember: ties sloping inwards may encourage water penetration, and mortar droppings may also be a problem. Good practice should avoid both these potential defects but they are not uncommon. Poor work can be expensive to resolve.

These photos show partial insulation. On the left the ties has been positioned but not the retaining washer - this can be seen on the right. When using partial insulation extra ties are required to support the boards.

Method of keeping cavity cleanMethod of keeping cavity clean

Bad positioning of DPC into the Bad positioning of DPC into the cavity may result in a build up cavity may result in a build up of mortar droppingsof mortar droppings