Crack Stitching can be used in isolation or accompanied by a range of Thor Helical methodologies to restore structural stability to a building. These are single bar installations that are generally incorporated into mortar bed joints to traverse cracks and dissipate stresses within masonry over a larger surface area whilst still allowing small movements of the structure due to natural temperature variations. Crack Stitching may also be tied through masonry to reinstate failed corner details, or incorporated into slip ties to provide structural connections across movement joints.
The series of photographs below illustrate an example of a before and after Crack Stitch installation used in conjunction with Masonry Beam to return structural integrity to a crack brick wall caused by root ingress from a climbing ivy that was allowed to get out of control.
Illustration crack damage to south east facing wall between ground and first floor windows. Remnants of climbing plant are still visible across wall.
Illustration of crack damage below ground floor window on same south east wall.
Illustration of crack damage radiating from front door opening on south east wall.
Series of photographs illustrating combination of Crack Stitch and Masonry Beam specified to return structural integrity to the wall.
Series of photographs illustrating the completed installation of bars
and repointing of chases in cement mortar. Cracked bricks were repaired
with Thor E Resin coloured to match as closely as possible with existing
A series of photographs illustrating Crack Stitch bars installed internally on a flint walled house to strengthen weak points around a window opening.
Crack Stitch bars chased 55 - 60mm into wall returned into window reveal.
Adjacent photo illustrating wall after chases have been filled and skim coat plaster applied ready to receive new decoration.
Photographs below illustrate an internal crack repair to walls and plaster finishes. The parent structural element of these walls are or circa 19th Century vintage constructed in a combination of random flints and soft Norfolk red bricks within a lime mortar matrix. The property had been updated and modernised internally in the 1980's using modern gypsum plaster finishes. Some movement had taken place in the interim period due to leaking drainage problems leading leading to cracks around weak points such as windows. As the 1980's modernisation had used gypsum plaster we used the same to make good wall chases and the like, although more sypathetic lime plaster materials could have been used if required.
Crack Stitch installation, before during and after repair photographs. Note that cement mortar an brick repair mortar are still 'green' and upon further drying will blend in with existing building fabric.
From an environmental, economic and aesthetic perspective the Thor Helical system is quick to install, thus reducing on site time; minimizes waste by retaining large sections of a building that would have traditionally been replaced, and retains the original fabric of a building where masonry may be difficult to match.
As an approved specifier and installer of the Thor Helical products we can offer an insurance backed 10 year warranty on Crack Stitching works for a small additional fee through Construction Guarantee Services Limited