Cracks in walls commonly appear in areas where the brickwork is over stressed, such as over front doorways and below larger windows- particularly bay windows. The stress and small movement of the brickwork can be caused by fluctuations in temperature, variations in moisture content or small movements in the ground which supports the walls.
Cracks are the result of the movement of the brickwork beyond that which can be facilitated by the masonry materials.
Cracks can be divided into three categories-active, passive or cyclical. Cyclical cracks open and close seasonally, passive cracks are those which do not increase in length or width and active cracks are those which increase in width and/or length.
How We Repair Cracked Walls
Cyclical and passive cracks-and generally those which are smaller in width- can be repaired using a brickwork stitching technique.
This reinforces and improves the strength of the wall, whilst allowing for a small amount of flexibility and cyclical movement.
Crack stitching involves bonding shaped and twisted stainless steel rods called Heli bars into the wall to stitch the masonry across the crack at regular intervals.
The process involves:
-Cutting horizontal channels at regular intervals in the masonry-to the correct depth- across equal sides of the crack.
– The cuts are flushed out with fresh water to remove any debris and to reduce moisture being sucked out of the grout/resin by the porous masonry.
-The channel are filled with grout/resin from the back.
-The Heli bars are pushed into the channels to ensure that they are fully encapsulated in the grout or resin. The twisted shape of the rods allow for some movement with their spring like nature whilst also interlocking with the bonding agent.
-The cuts are then repointed to disguise the crack stitching and to match the repointing of the rest of the wall as close as possible.
-The cracks in the wall will also be sealed to ensure no further expansion or increase in volume due to water in cracks freezing in cold weather.
The Benefits of Crack Stitching
•Avoids the need to re-build masonry.
•Crack stitching repairs are repointed after to colour match the rest of the wall, making the repair invisible.
•The heli bars accommodates small movement in the masonry and also provides support to prevent further cracking.
Wall Tie Replacement
Wall ties are small strips or bars made of metal which span the cavity and tie the external and internal walls together.
If a wall tie corrodes, the build up of the resultant rust can cause the wall tie to expand in size. This can create pressure on the surrounding masonry and can cause bulges and cracks in the wall and mortar bed.
We can install replacement wall ties. These can be used with brick, block, concrete and timber.
This is a fast and effective service.
If you are interested in our cracked brickwork or wall repair services, call us on 01216679930 to arrange a survey.
Alternatively simply fill out our contact form and we shall get back to you promptly.