Crack Stitch Repair
Vertical cracks in a wall and stepped cracks in brickwork can be fixed with a Crack Stitch Repair. The repair process uses stainless steel Helical Bars and a specially formulated cement to fix the bar into the mortar bed joint. Crack Stitching Kits are available from Helifix, Ancon, Twistfix and Permagard.
The video on the right is from Helifix. It shows you how to carry out a crack stitch repair using a kit that they sell which includes their own brand of Crack Stitching Bars, called HeliBars, and their cement called HeliBond.
The procedure is similar to a Timber Resin Splice.
The first stage is to remove mortar from the bed joint by raking it out with a power tool or by hand. Care must be taken to avoid damage to the brick face. The groove only needs to be a couple of inches deep on a solid wall, less on a cavity wall.
Then clean out the dust and debris from the groove in the mortar, and check that your Crack Stitching Bar will fit into the slot okay. It helps to have a slightly longer groove than needed. Remove the bar.
Follow the manufacturer’s instructions to mix the cement grout and load it into a skeleton gun (sealant gun) and apply a generous bead of the grout to the back of the groove. Push the bar into the compound, and ensure it is located at the appropriate depth, and parallel to the brick face. Then add another bead of cement and smooth off.
Leave the cement to dry, until it has at least skinned on the surface, and then repoint your brickwork with mortar to match existing.
If required you can carry out additional Crack Stitch Repairs between 2 and 6 courses apart. However it is advisable to only work on one crack stitch repair at a time.
When repairing cracks in a wall it is important to obtain professional advice from a structural engineer to ensure the work being carried out is appropriate.
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Background image credit flickr.com/photos/imagix3d/3313309023