250MM STST VISTA TYPE 4 HOUSING TIE VE4-250 250 PACK

Product Code: 72TIE0070

WTS4: Type 4 Wall Ties: Masonry Light Duty

Type 4 wall ties are light duty, suitable for box-form dwellings up to 10 metres high with leaves of similar thickness, including internal separating cavity walls. 

Use in flat sites in towns and cities where the basic wind speed does not exceed 25 m/s and the altitude is not more than 150m above sea level.

Recommended Positioning and Density

For walls in which both leaves are 90mm or thicker, masonry ties need to be placed at not less than 2.5 per square metre (900mm horizontal x 450mm vertical centres).

The ties should be evenly distributed throughout the wall area, with the exception of around openings and should be staggered where possible.

Insulation Board

Where insulation board is installed within the cavity and restrained by ties with insulation retaining clips (Simpson Strong-Tie ref. IRC001), it may be necessary to reduce the horizontal spacing of the ties to 600mm.

At vertical edges of an opening, unreturned or unbonded edges, and vertical expansion joints - additional ties should be used at a rate of one per 300mm (height) and located not more than 225mm from the edge.

Length of Tie and Embedment

Wall ties should be of the correct length to ensure they are fully embedded in the masonry.
The tie should have a minimum embedment of 50mm in each leaf, but also allow for site tolerances relating to the cavity width and centring of the tie.

The recommended tie lengths will therefore achieve an embedment of between 62.5mm and 75mm.