The subject building was a traditionally built end of terrace domestic Victorian residence. There was significant visible outward leaning movement and the dropping of brickwork arches was reported to the pentagon bay window.
This pentagon shaped two-storey bay window with a brickwork crenelated parapet wall was found to be unstable. It was suffering from rotational outward movement, dropping of the brickwork arches at ground floor level, and significant rotational outward movement to the masonry columns, causing spreading and dropping of the brickwork arches above, which was of great concern. Similar movement was reflected in both the front and left side elevations, with outward bulging noted and some cracking of the front ground floor arches.
The movement noted was progressive and advanced, and was attributable to ineffective, inadequate restraining to the bay window structure which has allowed the masonry columns to bulge outwards and the brick arch to spread and drop, cracking the brickwork above and becoming unstable and in danger of collapse.
Action Wall Ties proposed remedial scheme was to provide a viable repair by introducing Bed Joint Reinforcement – beaming, fenestration lintel repair, lateral restraints, special diamond drilling for grout tie injection and resin bonded ties to reinstate the uniformity of the wall and providing restraint.
We provided temporary support to the underside of the ground floor, then the underside of the first floor window brick arches, removed debris from the cracks and deployed AWT designed and developed realigning cramping equipment to realign the masonry elements, closing open joints and returning the arches back to a more level line with the adjacent brickwork, along with the masonry columns, and into a more upright line before proceeding with the proposed drilling and reinforcing.
As indicated with red double dotted lines on our proposal 1, 2 & 3, we introduced twin 8mm stainless steel corded joint reinforcement, forming a deep masonry beam.
As indicated with horizontal green parallel lines on our proposal 1, 2 & 3 to form the beam and reconnect the bay window elevational brickwork, once the brickwork had been realigned with AWT designed drilling equipment we diamond drilled a 20mm hole through each elevation of the bay, through the main elevational wall and chased internally into the main elevation wall, injecting a grouted 8mm helical bar.
As indicated with vertical green lines on our proposal 1, 2 & 3, to the underside of the fenestration openings head, we drilled for, and installed, grouted 8mm helical stainless steel pins through the brick arch and passed them into the line of the deep masonry beam, installing them within the existing masonry.
As indicated with yellow stars on our proposal 2, we drilled for, and screwed directly into timber floor joists, 8mm stainless steel lateral restraints, all resin bonded to the masonry.
As indicated with vertical green parallel lines on our proposal 1, 2 & 3, once realigned and columns made more upright, we drilled with specially designed drilling rigs from the top of the parapet down through brickwork and passed into the top of the masonry columns in order to inject a grouted 12mm stainless steel grip bar.
To cracked brick arches scheduled for reinforcement listed above, we raked out the existing cracked mortar and repaired with new coloured sand and cement mortar to approximately 20mm in depth.
Action Wall Ties have developed methods and trained skilled experienced operatives to strive to finish our works to always be sympathetic with the existing by attempting to match replacement bricks, pointing style and mortar mixture for texture and colour.
Action Wall Ties services are available to client’s in the South east i.e. in London & in Kent in Sussex & in Essex