Older properties, particularly Victorian houses are vulnerable to aging defects that affect brickwork facade walls, a fact that was made shockingly evident in a recent project carried out by a Twistfix-registered contractor.
The property is located in the historic market town of Bishop's Stortford in the beautiful county of Hertfordshire. An end-terrace Victorian house built circa 1840, the building is owned by a private landlord who had become extremely concerned at the large extent of bulging walls and cracking brickwork that was clearly visible in several areas.
To confirm the immediate visual inspection, a full survey was carried out by NBS Surveyor James Wiggins to determine the exact cause and extent of the problem. Bowing of the masonry was discovered to be significant, leading to cracking at the party wall's junction with the main structure. Gaps had also appeared at both ceiling level, first floor level and adjacent to stud partition walls, a problem added to by the extensive corrosion and subsequent failure of existing lateral restraint plates that had been installed more than 50 years previously. At the property’s front elevation, severe cracking had also become evident due to complete lintel failure, a worryingly-common problem in properties of this construction and vintage.
Using the results of the detailed inspection, specialists at NBS created a full remedial plan to repair the damage and prevent against its recurrence. The plan involved reinforcing the brickwork by installing 5 bands of Twistfix helical rods into the front wall, around the full length of the gable wall and along the rear elevation. These reinforcing rods formed deep masonry beams over window openings and strongly tied together the property's midriff; distributing all structural loads right across the most prominent areas of bowing and into more secure masonry
A plan to increase lateral restraint was devised using a philosophy of distributing the buckling forces of the bowing wall back into the main structure of the building. Tying the external front wall to the party wall was achieved with the use of Twistfix 2m crack stitches; in an 'L-shaped' grouted tie, the stitches were chased from the party wall before being drilled directly through the external front wall. At the ground floor level, the party wall was tied with the use of 1m grout ties which were subject to several successful pull-out tests once the grout had fully set. Epoxy crack repair resin was used to fill and seal all cracks; allowing the reinforced brickwork to immediately take compressive loads
Twistfix lateral restraint ties were used to provide additional tensile restraint and to spread the loads as evenly as possible back into the structure. The 1m long stainless steel ties were installed at 600mm intervals to fix the front and rear elevation brickwork to the floor diaphragm and to secure the gable wall to the stud partition walls; providing an effective solution and permanent restraint to all the bowing walls.
After repointing and replaceing the rusted patress plates, the repairs are practically invisible and the need for an expensive remove-and-rebuild process has been completely negated. Covered by a full 10-year insurance backed guarantee, the Victorian house now has its structural integrity fully restored.
For more information on our range of masonry repair solutions for bowing walls and cracking brickwork, please contact 0845 123 6006 or email firstname.lastname@example.org.