Cross-Stitching Cracks Cross-stitching is a repair technique for longitudinal cracks which are in reasonably good condition. The purpose of cross-stitching is to maintain aggregate interlock and provide added reinforcement and strength. The tie bars used in cross-stitching prevent the crack from vertical and horizontal movement or widening. Cross-stitching uses deformed tie bars drilled across a crack at angles of 35 degrees. A number 6 bar is sufficient to hold the joint tightly closed and enhance aggregate interlock. The bars, spaced 20-30 in. from center to center, alternate from each side of the crack. Heavy truck traffic and airplane traffic require the 20 in. bar spacing. A 30 in. spacing is adequate for light traffic and interior highway lanes. Do not stitch a transverse crack which has assumed the role of an adjacent joint. Stitching will not allow transverse joint movement (open and closure). A new crack will likely develop near a stitched working crack or the concrete will spall over the reinforcing bars.