Outline and purpose
Wall ties are a flexible stainless steel fitting that are used to tie the outer masonry leaf of the wall to the stud framework. Their purpose is to distribute and absorb differential movement between the timber frame and the masonry leaf. They are secured to the stud framework penetrating the sheathing material; the action previously stated above of marking the full height studs on the breather membrane is taken so that wall ties can be positioned correctly.
Installation considerations
There are several key points that need to be adhered to when installing wall ties:
All wall ties must comply to I.S. EN845-1:2003 + A1:2008 and should carry the mark of the manufacturer and wall tie type.
Wall ties must be nailed to the studwork; attaching wall ties to sheathing material only is not acceptable.
The uppermost wall ties should be positioned 225 mm below the top of the masonry outer leaf.
The bottom most should be positioned 225 mm above the DPC level unless specified otherwise.
They should not exceed a horizontal spacing of 405 to 605 mm depending on stud centres.
They should not exceed a vertical spacing of 450 and 225 mm at opes through the external wall.
They should not exceed the spacing of 225 mm at movement joints and must be staggered at either side of the joint.
Each tie must also extend a minimum of 50 mm into the masonry outer leaf.
