Wall ties at movement joints

TECHNICAL GUIDANCEWALL TIES AT MOVEMENT JOINTS6.1/25 – April 2011 (first issue)QUESTIONCan slip ties be used in place of additional wall ties at movement joints in masonry walls?CONSIDERATIONSn A vertical movement joint can a ect the structural stability of a masonry wall . To maintain thestability of the masonry wall, on either side of the joint, additional wall ties should be provided.n NHBC Standards clause 6.1 - S5 and BS 5628-3 ‘Code of practice for the use of masonry’describes the provision of additional wall ties on either side of a vertical movement joint whichpasses through one leaf of a cavity wall.ANSWERStructural stability of a wall on either side of a vertical movement joint, through one leaf of a masonrycavity wall, can be maintained by the provision of additional wall ties on either side of the joint.These ties should be located across the cavity within 300mm of each side of the joint and at maximum300mm centres vertically (see figure 1).Alternatively, stability can be provided by the use of slip ties (see figure 3) across the movement jointspaced at maximum 300mm centres vertically (see figure 2). In this case, additional wall ties, acrossthe cavity, are not required and wall ties can be spaced at normal spacings as if the movement jointwas not there.page 1 of 2

6.1/25 – April 2011300mm max300mm max300mm max300mm max300mm max300mm maxFigur e 1Figur e 1Figur e 1300mm max300mm max300mm maxFigur e 2Figur e 2Figur e 2Plastic sleeve (debonded end)Plastic sleeve (debonded end)Plastic sleeve (debonded end)Typical slip tieFigur e 3Figur e 3Figur e 3Typical slip tieTypical slip tieNHBCNHBC House, Davy Avenue, Knowlhill, Milton Keynes, Bucks MK5 8FPTel: 0844 633 1000 Fax: 0844 633 0022 www.nhbc.co.ukpage 2 of 2HB1674 06/11