Acoustic Wall Ties complying to Robust Details and Building Regulations Part E.

Suitable for cavities from 50mm to 100mm in domestic houses and small commercial buildings up to 15 metres in height.
With a measured dynamic stiffness of <113MN/m³ this Acoustic Wall Tie meets the performance requirements of Building Regulations Part E for use in external masonry walls.

Available in two lengths:

BAWT/200 - 200mm for 50-75mm cavitites
BAWT/225 - 225mm for 76-100mm cavities

Wall ties should be pressed down in, and surrounded by, fresh mortar. In order to show more details of the application, mortar has been excluded from the photography in this literature.

To ensure cavity wall ties are effective at tying the leaves together they should be installed as the inner leaf is constructed and not simply pushed into a joint.

Ties should be installed with a slight fall to the outer leaf, never towards the inner leaf as this could provide a path for moisture to cross the cavity.

The drip part of the tie should point downwards and be positioned near the centre of the open cavity. Ties with multiple drips, like the Type B can often be positioned centrally as part of the drip will normally be near the centre of the open section of a partial fill cavity.

Installed ties should be clear of mortar droppings to allow the drip to function and prevent water from crossing to the inner leaf of masonry.


Length of Tie and Embedment

Wall ties should be of the correct length to ensure they are properly embedded in the masonry. We recommend tie lengths which achieve an embedment of between 62.5mm and 75mm.

A tie, 225mm long, would be the minimum length recommended for a 100mm cavity. 62.5mm + 100mm + 62.5mm = 225mm

Density and Positioning of Ties

Typical Layout of Wall Ties Indicating Maximum Spacing Standard spacing for cavity brickwork 900mm x 450mm centres in a staggered pattern (2.5 ties per m2)



For walls in which both leaves are 90mm or thicker, ties should be used at not less than 2.5 per square metre (900mm horizontal and 450mm vertical centres). This spacing may be varied by building regulations. Ties should be evenly distributed over the wall area, except around openings, and should be preferably staggered. At vertical edges of an opening, unreturned or unbonded edges, and vertical expansion joints, additional ties should be used. Such ties should be located at 300mm vertical centres, positioned not more than 225mm from the edge.