Edwardian portico structure with stucco columns cracking and failing – stabilising remediation works involved precision diamond drilling into the edge of the rounded columns directly into the centre of a half brick wall and the injection of grout
The subject building was a substantial, traditionally-built, elegant Edwardian Stucco finished domestic house in Central London.
This period property required work to remedy cracking and parting of the entrance porch structure without detracting from the look of the property.
Action Wall Ties have highly trained staff with a wealth of experience in dealing with period properties. AWT used their own design of diamond drilling equipment to drill for, and install, ties to strengthen the structure. The property was then made good using special mortars to match the existing finish.
Detailed Case Study
Defect
Cracking to the junctions of the front portico stucco columns with the main elevational walls was reported and noted.
Discussion
An underpinning scheme was completed, addressing the downward movement leaving the superstructure to be reconnected. Action Wall Ties’ remediation works were designed to assist in restraining the masonry to return the integrity to the structure.
Structural repair solution
The remediation works involved precision diamond drilling into the edge of the rounded columns, directly into the centre of a half brick wall by 1800mm each way to accommodate the injection of grouted ties, reconnecting the columns and walls (as indicated with green lines).
With the structure stabilised the cracked junctions of the columns with the main elevation were raked out cleaned and injected with cementitious grout, finished and made good with concrete repair mortar.
Action Wall Ties have, over many years, developed specialised equipment and methods to facilitate precision diamond drilling in almost any location, into almost any substrate, drilling 20mm diameter holes up to 3 meters long, through to 80mm diameter holes to almost any length, to accommodate the proposed remediation works (i.e. the removal of corroding steel and or installing many types of fixings).
Action Wall Ties have developed methods, and trained skilled experienced operatives, to strive to finish works to be sympathetic with the existing by attempting to match replacement bricks, pointing style and mortar mixture for texture and colour.
Action Wall Ties (AWT) are specialists in masonry reinforcement and repair in London and Kent, providing professional solutions to a wide variety of structural problems. Contact us on 01227 721 255, or email us.
A 1930s purpose built library in Welling, near Dartford, Kent. Corroding support angles to the flat brick soldier course lintel required bed joint reinforcement beaming, fenestration lintel repair, grout tie injection and resin bonded ties and removal of the corroding angles.
The subject building was a substantial purpose built library constructed in the mid-1930s of brick on a concrete foundation.
Structural Problems and Issues
Visible cracking and lifting movement noted to the window openings to the top floor front and two side elevations. A total of 20 windows.
The external brickwork soldier course formed a flat arch above the window openings. The flat arches were built on a 50mm × 50mm mild steel angle that was found to be heavily corroding and delaminating.
Severe corrosion of the embedded mild steel support angles and its resulting expansion had caused severe distress to the adjacent brickwork.
The internal brickwork was being supported by an independent concrete lintel.
Structural Repair Solution
AWT completed a remedial scheme, introducing bed joint reinforcement beaming, fenestration lintel repair, grout tie injection and resin bonded ties.
1. Bed joint reinforcement beaming:
The introduction of two rows of twin cord reinforcement, forming a composite deep masonry beam – as indicated with red double dotted lines on our proposal images.
2. Fenestration lintel repair:
To the underside of the fenestration openings head, we drilled for, and injected, grouted 8mm helical stainless steel pins through the brick arch, passing into the line of the composite deep masonry beam installed within the existing masonry – as indicated with green parallel lines on our proposal images.
3. Resin bonded ties:
Within the area of the beaming we drilled for (wherever possible to the centre of a brick), and resin bonded, new 6mm stainless steel remedial ties (four per square metre) above window openings, then re-pointed disturbed areas only with coloured sand and cement mortar.
After the proposed reinforcing works had been completed the windows were removed (by others) to enable the removal of the mild steel angles and making good of the brickwork.
High Quality Structural Repairs
The gallery below shows the completed structural repairs after 15 years. The repairs are as good as new.
Traditional building methods are only able to provide short term, cosmetic repairs. Our skilled structural repair specialists can identify the underlying causes of structural defects and provide long lasting repair solutions.
Councils, housing associations and other public sector organisations across the South East have turned to AWT for cost effective, long term solutions to a wide range of structural issues.
Action Wall Ties (AWT) are specialists in masonry reinforcement and repair across Kent and London, providing professional solutions to a wide variety of structural problems and issues from cracks to wall movement and window sill defects. Contact us on 01227 721 255, or email us.
Victorian bay window with spreading and cracking masonry
A much loved family home in South East London featuring an ornate brick and masonry Victorian bay window with spreading and cracking masonry. Diamond drilling through the brick arches and injection of grouted cords and bed joint reinforcing restored the property to its former glory.
This building was a traditional two-storey mid-terrace domestic residence in Blackheath, SE London, of Victorian vintage with a pitched tiled roof.
Problem – Bay Window Cracking/Dropped Arches
The front bay windows showed visible distortion and distress, accompanied by significant cracking to both main brickwork and brick entrance arches, which had also dropped.
Causation
It was clearly evident that the bay window had rotated away from the main building line, owing to subsidence.
The bay window’s foundations were shallow, compared with those of the main building.
This situation had been exacerbated by the close proximity of a tall tree that was further desiccating the clay subsoil, though the subsidence was not deemed severe enough at the time to warrant underpinning.
Bay Window Repair Solution
The bay window was tied back to the main elevation using stainless steel bed joint reinforcement and one core installed into diamond drill holes, indicated with green lines. This served also to beam up the brickwork and repair the cracking. In addition, the bay was tied back to the two floors behind to provide proper lateral restraint.
The arch was pinned up, using stainless steel pins, and resined into the brickwork above. After installation, pointing was raked out, reinstated and tinted to match the existing (see coloured remedial works on our proposal picture).
Arboricultural works were undertaken on the tree (by others), to reduce the crown and accordingly lower its water demand from the underlying clay.
Long Lasting Structural Repairs
The gallery below shows AWT’s completed structural repairs after 15 years. This is why homeowners across the SE of England can trust AWT with their period properties. Our structural repair techniques provide long lasting, cost effective repairs that maintain the beauty of period properties.
Before
Before
After
After
Action Wall Ties (AWT) are specialists in masonry reinforcement and repair, providing professional solutions to a wide variety of structural problems. We have many years experience working on period properties, listed buildings and heritage structures.
For expert structural repairs in London, Kent, Surrey and Sussex please contact us on 01227 721 255, or email us.
Stabilizing stone and flint dormer window at King’s School, Canterbury – diamond drilling for, and installing, grouted ties
King’s School is possibly the oldest school in England, believed to have been established over 400 years ago. AWT were engaged to undertake remedial works to stabilise a stone and flint fronted gable dormer window of this substantial, historic school building. We used lateral restraints and grout ties to remedy the problem and offer an effective repair solution.
Problem – movement and rotation of gable masonry
• The dormer gable masonry was of stone window mullions and copping stones with a flint infill backed with brickwork.
• The dormer gable masonry had suffered from significant outward movement, leaving a gap between the flashings and the dormer roof.
• The masonry appeared to be rotating outwards on the joints to the stone window mullions.
• No fixings to the masonry and the roof structure were noted.
Discussion
From our findings it was apparent that the building had suffered from movement over a period of time. It was deemed that this movement was progressive, due to current ineffective and/or inadequate restraining.
The Repair Solution – Lateral Restraints
AWT completed a remedial scheme providing a viable repair, through the introduction of lateral restraints and grout ties to reconnect the substance of the wall and restrain the same.
• Grout ties: To connect the substance of the masonry stone and flint of the gable wall, AWT installed remedial grout ties by drilling for, and injecting, grouted 8mm helical bar – as indicated with green stars and parallel lines on our proposal plan images.
• Lateral restraints: In conjunction with the grout ties we installed stainless steel ties, screwed into the side grain of the timbers behind and resin bonded to the masonry – as indicated with yellow stars on our proposal plan images.
Action Wall Ties (AWT) are specialists in masonry reinforcement and repair including historic flint and stone walls, in Kent, Surrey, London and Sussex.
Our Lateral restraint solutions are permenant and effective, creating a better than new outcome.
We are successfully providing professional solutions to a wide variety of structural problems. Contact us on 01227 721 255, or email us.
Historic dockyard Chatham The Smithery – long 3500mm diamond drill for and installing grout ties and Cintec ties
The Smithery at The Historic Dockyard Chatham, a Scheduled Ancient Monument and Grade II* listed building.
The Smithery, built in 1808 and the last building within the walls of The Historic Dockyard Chatham on the English Heritage ‘at risk’ register has been saved.
This important historic building fell out of use in 1974 and is in a very poor condition, funding has enabled emergency stabilisation works to commence.
Action Wall Ties diamond drilled a pattern of 50mm diameter holes horizontally, 3500mm in depth through mass brickwork, prepared for the supply of Cintec sock anchors M16 x 3500mm anchors and inflated in accordance with the specification and manufacturers recommendations by certified operatives.
Action Wall Ties (AWT) are specialists in masonry reinforcement and repair, providing professional solutions to a wide variety of structural problems. Contact us on 01227 721 255, or email us.
Stabilising Victorian gable wall stone corbels, pediment and copings – diamond drilling for, and installing, grouted and Cintec ties
The subject building is a substantial Victorian traditionally-built house featuring a gable embellished with substantial supporting stone corbels, coping stones and pediment in North London.
This property required work to remedy the rotation of the supporting stone corbels and dislodged copings without detracting from the look of the property.
Action Wall Ties have highly trained staff with a wealth of experience in dealing with period properties. We used our own design of diamond drilling equipment to drill for, and install, ties strengthening the structure.
Detailed Case Study
Problem: Stone Corbel Movement
The gable wall had a substantial stone corbel supporting the stone coping stones. Rotating and outward movement was noted to the stone corbel together with cracking to surrounding brickwork as well as dislodged coping stones and pediment.
Discussion
Action Wall Ties’ remediation works were designed to assist in restraining the masonry to return the integrity to the structure.
Stone Corbel Repair Solution
Remedial work by Action Wall Ties provided a cost effective long-term solution. The existing appearance of the building was maintained. Work was carried out with the minimal amount of disruption to residents and the environment.
The remediation works involved diamond drilling 38mm X 2000mm holes into stone corbels, and others into the pediment and stone coping, to accommodate installation of remedial Cintec 40mm sock anchors.
Cintec anchors installed in accordance with manufacturer’s recommendation and by Action Wall Ties’ trained certificated operatives.
Action Wall Ties serve customers throughout the South East i.e. in Kent, Greater London, Sussex and in Essex.
Action Wall Ties (AWT) are specialists in masonry reinforcement and repair, providing professional solutions to a wide variety of structural problems including issues with stone corbels, pediment and copings in Victorian properties. Contact us on 01227 721 255, or email us.
Large ornate Victorian square stone and brick bay window failing and rotating – stabilizing, realignment, reinforced and make good
The subject building was a substantial traditionally built semi-detached Victorian residence.
On our inspection we found a scaffold in place and it was apparent that a recent attempt at remedial works had been aborted with temporary timber props and packers left in place.
The handsomely designed front elevation and bay window structure, consisted of a ground floor cant bay of brickwork columns, arches with stone corbels, and supporting columns to each external corner supporting a two-storey square bay window of stone column brickwork with stone quoins above.
To the ground, first and second floors, signs of distortion spreading of the 13½ inch brickwork arches with stone quoins to the front and right side cracking the supported brickwork spandrels above were noted. What appears to be a recently installed bed joint reinforcement and resin injected into the open bed joints was also noted.
Discussion
The movement to this complicated bay window structure was believed to be progressive due to ineffective, inadequate, restraining which has allowed the brick arch to spread drop and the brickwork above to drop and crack, resulting in the stone columns leaning outwards and becoming unstable.
Structural repair solution
Although we can make no comment about the suitability/efficiency of either the design or works undertaken as part of the aborted scheme, the first stage of the remedial works that we undertook was to provide temporary support by deploying AWT designed and developed realigning cramping equipment to realign the masonry elements closing the open joints. Thereafter, we used Action Wall Ties’ specially designed diamond drilling jigs to drill the full width of the bay, through all the different elements, and install stainless steel cords locking the bay together adding tensile strength and forming composite beams together with lateral restraints, finally making good.
As indicated with red double dotted lines on our proposal 1, we introduced twin 8mm stainless steel corded joint reinforcement to form a deep masonry beam.
As indicated with green parallel lines on our proposal 1, to form the beam and reconnect the bay window elevational brickwork and stone quoins, we diamond drilled a 20mm hole through each elevation and installed a grouted 8mm helical bar.
As indicated with green stars on our proposal 1, to reconnect the head of the bay windows to the main elevational brickwork, we diamond drilled a 20mm hole through the side of the bays into the main elevational wall and installed a grouted 8mm helical bar.
As indicated with yellow stars in a circle on our proposal 1, in conjunction with the temporary supporting we drilled a 12mm hole counter bore to 20mm, and screwed directly into floor joists 8mm stainless steel lateral restraints and, with a thick stainless steel washer and nut, applied pressure to assist in realigning the masonry. Once completed this was resin bonded to the masonry.
To the second floor cracked capita, we drilled for, and resin bonded, new 6mm stainless steel remedial ties, making good to disturbed areas only with coloured sand and cement mixture.
Making Good Pointing
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 be sympathetic with the existing by attempting to match replacement bricks, pointing style and mortar mixture for texture and colour.
Failing and Rotating Victorian Pentagon Bay Window
Unstable Victorian pentagon bay window. The masonry of this 5-sided bay window was failing and rotating. It required stabilising, realignment and reinforcement. AWT was able to restore the structural integrity of the ornate period bay window without slow and expensive rebuilding work.
The bay window at the corner of this end-of-terrace domestic Victorian property was in danger of collapse. There was significant visible outward leaning movement and the dropping of the brickwork arches in the pentagon bay window.
The Structural Problem
This two-storey, pentagon-shaped (also known as 5 lite/5 panel/5 pane) bay window with a brickwork crenellated parapet wall was found to be unstable. It suffered 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.
Sagging Bay Brickwork
Cracking Brick Arches
Gaps & Cracks
Dropping Brick Arches
Collapsing Brickwork
Leaning Bay Window
The structural defects in the bay window were having a knock-on effect on the rest of the house. 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 by the AWT survey team was progressive and advanced. The structural failings were attributable to ineffective, inadequate restraining to the bay window structure, This has allowed the masonry columns to bulge outwards and the brick arches to spread and drop, cracking the brickwork above and becoming unstable and in danger of collapse.
The Structural Repair Solution
Action Wall Ties proposed remedial scheme was to provide a viable repair by realignment and then introducing Bed Joint Reinforcement Beaming. Other structural repair techniques were also used including:
brickwork arch lintel repair
lateral restraints
special diamond drilling for grout tie injection
resin bonded ties
This combination of specialist structural repairs enabled the AWT team to reinstate the uniformity of the wall and provide restraint to the masonry.
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 proposals 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 proposals 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 proposals 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 proposals 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.
For cracked brick arches scheduled for reinforcement listed above, we raked out the existing cracked mortar and repaired it 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 work to always be sympathetic to the existing structure. Where possible AWT match replacement bricks, pointing style and mortar mixture for texture and colour.
Restored Pentagon Bay
Realignment of Brickwork
Realignment of Bay
Bay Window Repair
Reinforced Bay Window
Restored Bay Masonry
Period Bay Repairs
5-Pane Bay Repairs
Bay Window Crack Repair
As can be seen in the gallery images, AWT’s specialist structural repair techniques were able to save this beautiful pentagon bay window. The period features were preserved. A long-lasting repair to the structure was achieved without any visible fixings and without rebuilding work.
Restoration of Collapsing Bay
Restoration of Period Bay
Structural Repairs to Period Bay
Action Wall Ties services are available to clients in the South East i.e. in London & in Kent, Sussex & Essex. We regularly rectify problems and issues relating to cracking and movement around bay windows in properties of all ages and types.
Action Wall Ties (AWT) are specialists in bay window reinforcement and repair, providing professional solutions to a wide variety of structural problems. Contact us on 01227 721 255, or email us.
Imposing 1980s quadrangle designed head office building in Essex with failing brick slips. The contract for remedial fixing of the brick slips was awarded to Action Wall Ties.
The subject building was an imposing 1980s quadrangle design commercial head office building, over four floors, in four wings with entrance towers to each corner.
This building was undergoing a major refurbishment for new occupants Cofunds when some detached brick slips were noted. Action Wall Ties was invited by Como Interiors to undertake an inspection of the brick slips and any associated defects, and to report our findings and recommendations.
Action Wall Ties inspected Mayland house building, identified the defect, reported on our findings and recommended AWT designed fixing of some 20,000 brick slips.
Action Wall Ties was instructed and successfully completed the fixing of 20,000 brick slips to this building on budget and on program. Our work met with the approval of both Como and Cofunds.
The Structural Problem
The building was found to be of concrete frame construction, with cavity brickwork infill walls, an external skin of stretcher bond reddish multi-stock bricks constructed on each concrete floor beam with brick slip facing, and with windows up to the underside of the floor beam above in-between brick clad columns.
The external brickwork infill walls were found to be supported on the floor beam by approximately 60mm, with 50mm protruding to accommodate finishing and with brick slips bedded in front of the concrete floor beam, thus giving the appearance of brickwork. To each wing the brick slips formed a full brick soldier course with three courses of stretcher bond to the return wall and the entrance towers.
Since this building was built the concrete frame had shortened, and the bricks’ first irreversible expansion had taken place. We believed that these movements, together with thermal movement, had resulted in the sand and cement bedding mortar becoming detached from the concrete floor beam. Any further movement within the brickwork, and/or erosion/deterioration of the pointing mortar, could un-lock the brick slips allowing them to become dislodged and fall. Present-day practice is to mechanically fix all brick slips.
The Structural Repair Solution
Action Wall Ties have considerable experience in remediating brick slip defects and have developed methods and equipment to enable the successful fixing of brick slips in situ, avoiding damaging (i.e. cracking with impact hammer type drills) the delicate brick slips. With specially sharpened drills, developed to enable rotary drilling of the slips to complete the fixing, we inserted a special colour matched epoxy putty into the pre-drilled hole then drove a stainless steel fixing into the epoxy putty to fill hole, providing not only a mechanical fixing but bonding all the elements together. We then made good and sealed the access hole with coloured epoxy putty.
Action Wall Ties have developed a unique approach to fixing brick slip issues on low rise and high rise concrete frame buildings. Using their specialist drilling techniques and carefully designed fixings, AWT can repair brick slip defects in an economical manner that maintains the appearance of the building and minimises disruption.
Kent based AWT provide their expertise to customers in Kent, Essex, Sussex, Surrey & London. To arrange a survey or to discuss your project, please call us on 01227 721 255, email us or fill in the contact form.
The Hanger Lane Underpass in North West London is part of London’s North Circular Road. This vital part of the road infrastructure required specialist structural repairs because the parapets, which have very large copings, were becoming detached. Transport for London contracted AWT to install remedial fixings and stabilise the underpass.
The Structural Issues
Action Wall Ties’ expertise was sought to undertake the securing of large concrete copings to the Hanger Lane underpass retaining walls. The specification, provided by Transport for London, was to introduce a pattern of large stainless steel fixings to be drilled down into the concrete of the wall.
This presented a series of obstacles to overcome. Firstly, to enable the proposed drilling we had to initially design equipment and methods to enable the efficient drilling for the pattern of fixings. Secondly, we had to be self-sufficient for the delivery of water and electricity supply to the working place on truck mounted working platforms, together with all that is involved in working on the closure of a major road at night.
The Structural Repair Solution
To enable the efficient drilling Action Wall Ties designed and manufactured four working saddles that clamped over the head of the wall, each supporting two diamond core drilling rigs set at the correct spacings with connections for water, electricity and lighting.
To provide water to the diamond drills we mounted a large water tank and pumps with a diesel generator supplying power into a large Sprinter van, together with other mobile generators which provided the services required for the proposed works.
Works
With the access platforms in place the AWT designed manufactured drilling saddles were lifted and clamped into place and connected to the services (as listed above). Adopting wet diamond drilling techniques a pattern of 20mm holes 400mm deep were drilled. Each saddle was set in place to drill two holes simultaneously, and a second set by sliding the rig forward before resetting the saddle, deploying four maned drilling saddles to meet with the program.
The pre-drilled holes were cleaned before we resin bonded 16mm stainless steel grip bars, and made good the disturbed areas with coloured concrete repair mortar.
AWT can provide cost effective structural repairs for a wide range of structural faults including large infrastructure projects. We operate not only in London but across the whole of the South East of England. We have experience working on the road and rail network including work for Transport for London, many London borough councils and public sector organisations across the South East.
Action Wall Ties (AWT) are specialist structural repair contractors for large and small projects. Please get in touch to discuss your requirements. Contact us on 01227 721 255, or email us.
