Resin bonded ties Archives - Page 2 of 3

Bulging Gable Wall in NE London

Bulging End of Terrace Gable Wall

The owners of this Victorian / Edwardian end of terrace home in the Redbridge area of North East London called in AWT because of the significant outward bulging of the large gable wall of their property. There was also cracking to the internal gable end walls as well as to the internal party wall between the property and its neighbour.

Bulging gable repairs London 225x300 - Bulging Gable Wall in NE London

Gable structural repairs London 225x300 - Bulging Gable Wall in NE London

The Structural Problem

The AWT survey team visited the property in Woodford Green to identify the root cause of the visible bulging movement of the large, solid brickwork flank/gable wall. Due to aging, ineffective and inadequate restraining of the brickwork the entire gable wall was de-bonding and disconnecting with the rest of the masonry. This was leading to additional problems with the internal beams losing support.

Without structural repairs, the large gable wall would continue to pull away and eventually collapse. Traditional building methods would have required the partial deconstruction and rebuilding of the flank wall. Even then, it would not have solved the root cause of the problem – inadequate restraining of the gable wall.

The Structural Repair Solution

The team at AWT designed a structural repair package that would bring the brickwork back into alignment and add tensile strength to the structure. The specialist tools and fixings used by AWT enable them to restore the brickwork’s integrity without visible fixings or rebuilding work.

NE London Gable wall repairs 300x225 - Bulging Gable Wall in NE London

Bulging gable repair plan 300x225 - Bulging Gable Wall in NE London

Bed joint reinforcement beaming, grout tie injection and lateral restraints were employed to reinstate the uniformity of the wall and provide restraint. The formation of continuous beams within the existing masonry redistributed the upper storey loads while at the same time assisting in restraining diagonal cracking and bulging tendencies.

A specialist drilling rig, designed by AWT, was used to drill through the brickwork at a shallow angle to maximise the number of bricks connected by each helical, grout bonded fixing. The internal timber beams were reconnected to the masonry using resin bonded stainless steel fixings.

Cracked and disturbed areas of mortar were raked out and replaced with fresh mortar that was matched for colour, texture and pointing style.

AWT provided a long term solution for the bowing gable brickwork. By targeting the repairs exactly where they were required the work was completed swiftly and with minimum inconvenience to the residents. The hidden fixings used by AWT preserved the beauty of the old yellow stock brickwork.

Action Wall Ties are structural repair contractors with the specialist skills required to reinforce and repair large areas of bowing and bulging brickwork. AWT work along with property owners, architects, project managers and local authorities on large and small projects.

AWT are available in Kent, London, Essex, Surrey and Sussex. To arrange a survey or to discuss project details, please use our contact form, email us or call us on 01227 721 255.

Hazardous Masonry on Grade 2 Listed Building

Listed Building with Bulging & Cracking Masonry

This Grade II listed building in Thanet, Kent, was built in the 1840’s. The owners of this period property were facing the prospect of demolition and rebuilding of the facade of the property due to serious structural defects. Previous repairs using standard building techniques had failed to solve the structural problems. The property is currently in use as a nursery school. The business would have been forced to close for several months during traditional building works. AWT were able to repair the severe structural problems in a couple of weeks and preserve the period features without disrupting the running of the business.

The Structural Problem

The structural issues with this Victorian, Grade 2 listed property in Ramsgate, Kent were becoming hazardous due to the risk of falling masonry. Traditional building methods would have required several months of expensive and messy deconstruction and rebuilding work. The business would have been forced to close during the building works and the subsequent re-plastering and redecoration.

The front of the building had clearly visible bulging and cracking to the head of all the first floor windows. There were also cracks in the brickwork and stucco works each side and to the underside soffit of the window opening heads. There were clear signs of previous attempts at repairs that had failed to get to the root cause of the problems.

grade 2 listed structural defect - Hazardous Masonry on Grade 2 Listed Building — Buckling Brickwork

As shown in the photo below, the mild steel embedded within the masonry had corroded and the rust caused it to expand to several times the thickness of the original metal. The heavily corroded wrought iron arch bars were lifting and cracking the brickwork and the decorative stucco around the windows. The stucco stringer course frieze and cornice of the parapet wall was also cracking and distorting. Previous attempts at repairs had provided a temporary, cosmetic repair but had failed to solve the underlying structural defects.

The continued expansive corrosion of the wrought iron arch bars would, without remedial works, lead to the failure of the masonry and the risk of detached masonry falling from the building. Urgent structural repairs were required.

Rusting wall bars 300x225 - Hazardous Masonry on Grade 2 Listed Building

Rusted metal grade2 listed 300x225 - Hazardous Masonry on Grade 2 Listed Building

The Structural Repair Solution

Structural repairs to listed buildings need to be handled carefully to preserve the period features of the building. AWT have many years of experience working on listed properties. AWT can help the owners of listed buildings to navigate through the process of obtaining permission for repair works.

The specialist tools and techniques that AWT employ allow structural repairs to be made without the need for visible fixings. Using custom designed drilling and cutting tools, AWT can remove corroded metal fixings and embed new stainless steel fixings within the masonry.

In order to allow the business to remain open during the structural repair works, AWT arranged for the scaffolding to be erected at the weekend while the nursery was closed. The scaffolding was then double boarded and netted for safety. The AWT crew accessed the scaffolding from the side of the building allowing parents, children and staff to access the building as usual through the main entrance.

vertical wall ties 225x300 - Hazardous Masonry on Grade 2 Listed Building — Preparing Vertical Wall Ties

grade 2 listed structural works 225x300 - Hazardous Masonry on Grade 2 Listed Building — Drilling for Vertical Wall Ties

The AWT team used their specialist techniques to form composite beams within the existing brickwork and then remove and replace the corroded wrought iron arch bars. The team then reconnected and reinforced the brickwork above the windows and the parapet wall. They also repaired the cracked decorative stucco.

Before metal grade2 listed 225x300 - Hazardous Masonry on Grade 2 Listed Building — Before – Cracks & Broken Bricks

replacement lintel Thanet Kent 225x300 - Hazardous Masonry on Grade 2 Listed Building — During – Lintel Replaced

After metal grade2 listed 225x300 - Hazardous Masonry on Grade 2 Listed Building — After – Ready to Paint

This project required a combination of:

Bed joint reinforcement beaming
Grout tie injection
Resin bonded ties
Cintec sock anchors
Removal of corroded mild steel arch bars
Replacement arch bars
Brickwork repairs

The team at AWT strive to make all works as sympathetic as possible with the existing masonry. Not only do they try to match replacement bricks and pointing for colour and style they even match the mortar mixture texture.

The high quality fixings used by AWT combined with their thorough knowledge of structural defects ensures a long term solution to structural issues.

Action Wall Ties are structural repair contractors with the specialist skills required for listed buildings. AWT work along with property owners, architects, project managers and local authorities to preserve historic buildings.

AWT are available for large and small projects in Kent, London, Essex, Surrey and Sussex. To arrange a survey or to discuss project details, please use our contact form, email us or call us on 01227 721 255.

Failing Bay During Window Replacement

Bay Window Repairs During Fitting of New Windows

This period property in Southfields, South West London had failing bay window masonry. The old sash windows had been removed but fitting of the new windows revealed the bay window was unstable and out of alignment. Without professional structural repairs this would result in the collapse of the bay window masonry.

The Structural Problem

As with many Victorian/Edwardian properties, issues with the bay windows became apparent during the fitting of replacement windows. New box sash windows were being installed but the surrounding masonry was clearly out of alignment. Repairs were necessary before the replacement window work could be fully completed.

This property in London, SW18, had visible cracking and dropping to the front bay window masonry. The bay had lost the internal brickwork support during the removal of the old box sash windows. Cracking of the first floor masonry lintel components and rendered brickwork were clearly visible. The original internal supports at the head of the bay window structure had been removed together with the original box sash windows.

The combination of inadequate restraining, ageing and the removal of the structural supports to the first floor during the replacement of the original window frames left the bay window unstable. Without suitable structural repairs the bay window was in danger of collapse.

SW London Bay problems 300x225 - Failing Bay During Window Replacement — Before Bay Window Repairs

SW London Bay repaired 300x225 - Failing Bay During Window Replacement — After Bay Window Repairs

The Structural Repair Solution

To reinstate stability, the bay window structure required the internal supports to be reinstated plus reinforcement of the masonry. Temporary supports were installed to the underside of the first floor front bay window masonry lintel. All the debris was removed from the crack and the lintel was lifted into a more level line with the adjacent brickwork.

SW London Bay Reinforcement 290x300 - Failing Bay During Window Replacement

SW London Bay Supports 290x300 - Failing Bay During Window Replacement

Bed joint reinforcement beaming, grout tie injection, resin bonded ties, steel lintels and columns and some masonry repairs were all required. The formation of continuous beams within the existing masonry redistributed the upper storey loads to the supporting structure below while also assisting in restraining diagonal cracking and bulging tendencies. A bespoke steel box lintel frame supported on steel box columns was also fixed to the inside of the masonry columns.

The specialist techniques used by Action Wall Ties installed all the stainless steel fixings within the masonry leaving no visible fixings. Once the area had been redecorated the bay window looked as good as new.

AWT provide cost effective structural repairs for a wide range of structural faults including bay window reinforcement, realignment and lintel repairs. We operate not only in SW London but across the whole of London and the South East of England.

Read our frequently asked questions about bay window structural repairs.

To book a time for one of our surveyors to visit your property or to discuss your requirements, call us today on 01227 721255, email us at enquiries@actionwallties.co.uk or use our contact form to get in touch.

Concrete Frame Remedial Works

Inspection of this 9 storey concrete frame tower block revealed serious defects in the previous remedial works by another company. AWT installed remedial head restraints and wall ties to restore structural integrity.

The Structural Problem

This circa 1970s nine storey social housing apartment block in Dagenham that was over clad some two years previously with a polystyrene insulation system, that was deemed unsafe and removed to be replaced with PermaRock mineral Fibre EWI system. AWT was contracted to undertake an intrusive inspection of the wall ties, head restraints and visible concrete elements.

This concrete framed building’s cavity infill walls rely on wall ties to provide a degree of interaction between the two leaves, increasing vertical load and resistance to lateral movement (generally wind load) than two leaves acting separately and head restraints to tie the inner and outer walls to the concrete frame. Sound, correctly installed wall ties and head restraints are vital to the structural stability.

The British Standards Institution and the Building Research Establishment Specification Digest provide clear guidelines for the fitting of wall ties and head restraints in concrete framed buildings. Not only must the appropriate type and size of wall tie and head restraint be fitted but the number of fixings per square metre and the pattern of fixings within the masonry must also be considered.

Our Structural Repair Inspection

The AWT inspection comprised a limited inspection of the existing wall ties by drilling 12mm holes in the outer leaf of the brickwork to view within the cavity using an Endoscope. A metal detector was used to establish the remedial wall tie density and distribution and condition.

Our inspection revealed the original wire butterfly wall ties were in poor condition and found to be over their useful lifespan. Many of the original wall ties were also incorrectly installed or not embedded at all.

The remedial wall ties installed to replace the original butterfly ties were installed poorly and with insufficient population. Insufficient or incorrectly fitted head restraints dramatically reduce the load bearing capacity of the brickwork. If wall ties are broken, missing or incorrectly fitted this can allow the masonry to bow and crack.

The remedial wall ties were installed in an erratic pattern rather than the recommended pattern for maximum load capacity. The majority of the remedial wall ties had been installed in the mortar bed joints rather than into the bricks. The wrong length of ties had been fitted and insufficiently resin bonded. Many of these wall ties could be removed by hand!

The head restraint fittings were also incorrectly fitted with many being too long and protruding out of the brickwork rather than being securely fixed within the masonry.

The Structural Repair Solution

AWT provided high quality remedial work that is designed to last. Our skilled operatives take pride in their work and are committed to ensuring that every project they complete is safe.

High quality remedial ties were carefully installed in the correct pattern and density. Head restraints were also fitted to restore structural integrity.

AWT provide cost effective, safe remedial repairs to concrete framed buildings throughout London and the South East.

To book a time for one of our surveyors to visit your property, call us today on 01227 721255, email us at enquiries@actionwallties.co.uk or use our contact form to get in touch.

Bowed Flank Wall on Victorian Semi

Victorian semi-detached house with very large bowed flank wall. AWT used bed joint reinforcement, lateral restraints and resin bonded ties to realign and stabilise the bowing brickwork. As with many properties that AWT is called in to repair, the property showed signs of previous repairs that had failed to address the underlying structural issues.

The Structural Problem: Bowing Flank Wall

This substantial Victorian traditionally built semi-detached house is a domestic residence spread over three floors. As shown in the photo, the flank wall had a significant visible bulge in the centre of the wall at first-floor level. No significant cracking was noted. The third floor (top level) appeared to have been rebuilt.

The AWT survey team judged the movement of the masonry to be progressive and in need of stabilisation to avoid the entire wall collapsing. The previous rebuilding of the third floor brickwork failed to tackle the weakness in the structure that was allowing the brickwork to bow outwards.

What Causes Bowed Brickwork?

As is common with Victorian properties, the bowing masonry was due to some downward movement compounded by ineffective or inadequate restraining. Under the weight of the masonry above, and without strong enough fixings to tie it to the main body of the property, the brickwork bulges outwards.

The bulge may have been formed by some de-bonding of the brickwork (or cracking of the headers). It was common practice in buildings of this age for a 9-inch wall to be constructed as two half-brick walls with snapped headers to the external skin to save on expensive facing bricks. This results in a less structurally stable wall, compared to fully bonded brickwork, because the inner and outer skins of the wall are only connected by mortar.

The Structural Repair Solution

AWT’s remedial scheme involved the introduction of bed joint reinforcement, lateral restraints and resin bonded ties (see coloured remedial works on our proposal picture.) This added tensile strength and reinstated the brickwork’s integrity and the uniformity of the wall. After installation, the pointing was raked out, reinstated and tinted to match the existing.

1. Bed Joint Reinforcement:
The AWT team installed two rows of twin cord reinforcement, forming a deep masonry beam – indicated by red double dotted lines in the image.

2. Lateral Restraints:
In conjunction with the beam, 8mm stainless steel lateral restraints were introduced and screwed directly into timber floor joists’ end grain or into the side grain and resin bonded to the masonry – indicated with yellow stars in the image.

3. Wall Ties to De-bonding Brickwork:
Using specialist precision drilling rigs, the AWT team drilled for and installed new resin bonded, 6mm stainless steel remedial ties – indicated with blue lines in the image. Disturbed areas were re-pointed with colour matched sand and cement mixture.

Cost Effective Structural Repairs

Rebuilding work would have been, slow, messy and expensive. The affected rooms would also have been uninhabitable during the rebuilding work.

AWT was able to provide a long lasting structural repair that got to the root cause of the bulging brickwork. The bowing masonry was strengthened and brought back into vertical alignment. No visible fixings or rebuilding work was required. The vast majority of the work was carried out from the exterior of the property thus minimising the disturbance to the residents and to interior finishes.

Action Wall Ties (AWT) based in Canterbury, Kent, are specialists in masonry reinforcement and repair, providing professional solutions to a wide variety of structural problems in London and Kent. Contact us on 01227 721 255, or email us.

Victorian Crack Stitching and Lintel Repair

Victorian Property: Crack Stitching & Lintel Repair

Extensive superstructure reconnection and reinforcement after underpinning for a Victorian house in North West London.

The subject building was a substantial Victorian traditionally built semi-detached domestic house in London, NW3.

The Structural Problem

Click on the gallery images below to see the full extent of the damage caused by the structural issues. Evidence of previous, unsuccessful attempts to fix the structural issues by traditional building techniques can also be seen.

reconnect superstructure 10 230x120 - Victorian Crack Stitching and Lintel Repair

reconnect superstructure 8 230x120 - Victorian Crack Stitching and Lintel Repair

reconnect superstructure 13 230x120 - Victorian Crack Stitching and Lintel Repair

reconnect superstructure 12 230x120 - Victorian Crack Stitching and Lintel Repair

reconnect superstructure 6 230x120 - Victorian Crack Stitching and Lintel Repair

reconnect superstructure 7 230x120 - Victorian Crack Stitching and Lintel Repair

reconnect superstructure 4 230x120 - Victorian Crack Stitching and Lintel Repair

reconnect superstructure 3 230x120 - Victorian Crack Stitching and Lintel Repair

reconnect superstructure 1 230x120 - Victorian Crack Stitching and Lintel Repair

Signs of distortion and distress were noted, with localised cracked and dropped brick arches to the first and second floor levels of the square bay.

Significant cracking was noted to the external brickwork running from and to the ground, first and second floor window openings. The brick arch was missing from the first floor window and distortion, cracking and dropping were noted to the ground and second floor arches. The first and second floor window openings had temporary supports.

Causation

The movement noted was attributed to subsidence. Downward movement had allowed the brick arch to spread and drop and the brickwork to crack. The downward movement had been addressed by a recently completed underpinning scheme. Some de-bonding of the brickwork was also noted.

The Structural Repair Solution

1. Bed joint reinforcement:
We introduced two rows of twin cord reinforcement, forming a deep masonry beam – as indicated with red double dotted lines on our proposal images.

2. 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 deep masonry beam installed within the existing masonry – as indicated with green parallel lines on our proposal images.

3. Bay window repair:
To form a beam and reconnect the bay window elevational brickwork, we diamond-drilled a 20mm hole through each elevation, chased into the main elevation and injected grouted 8mm helical bars – as indicated with green horizontal parallel lines on our proposal images.

4. Crack stitching:
To stitch localised cracks we introduced single 8mm stainless steel corded joint reinforcement – as indicated with red single dotted lines on our proposal images.

5. Wall ties to de-bonding brickwork:
To brickwork within the beamed area and arches, where brickwork was believed to be de-bonding, we drilled for and resin bonded 6mm stainless steel remedial ties and re-pointed disturbed areas with a sand and cement mixture.

Signs of distortion and distress, with localised cracking, were noted to the external brickwork to the front entrance archway bridge, along with cracked voussoirs and the dropping of the brick arch and outward movement.

6. Resin bonded ties:
To stabilise the brickwork archway bridge, we introduced truss ties. To form the truss we drilled a 14mm hole at 45 degrees to the required depth, opened the entrance hole to 18mm, resin bonded 10mm stainless steel threaded rods, drilled a horizontal 14mm hole to the required depth, inserted the 10mm stainless steel threaded rods, fixed nuts and washers, resin bonded to the inner wall, tightened nuts to both sides and resin bonded to the outer brickwork.

7. Making good and pointing:
We raked out the existing mortar and repaired with new coloured sand and cement mortar to approximately 20mm in depth. AWT operatives are highly skilled in traditional building methods and always attempt to match replacement bricks, pointing styles and mortar colour to be sympathetic with the existing building.

High Quality Structural Repairs

The photos below show the property 14 years after the work was completed. The high quality structural repairs carried out by AWT are designed to last. Unlike traditional building repairs, our techniques get to the root cause of structural defects.

Victorian bay window repairs c2 300x225 - Victorian Crack Stitching and Lintel Repair

Victorian bay window repairs c3 300x225 - Victorian Crack Stitching and Lintel Repair

Victorian bay window repairs c1 300x225 - Victorian Crack Stitching and Lintel Repair

Action Wall Ties (AWT) are specialists in masonry reinforcement and repair, providing professional solutions to a wide variety of structural problems in Victorian properties in London, Kent and the whole of SE England. Contact us on 01227 721 255, or email us.

Bed Joint Reinforcement Beaming

Victorian property in Hampstead, NW3. Three-storey bay windows with pulling away outward movement, dropping brickwork (all with previous failing repairs) and bowing side flank wall. Repaired using bed joint reinforcement beaming, lateral restraints, crack stitching, and resin bonded ties.

The subject building was a substantial Victorian end-of-terrace domestic residence in North West London.

Structural Problems

Outward movement to the gable wall, patress plates and tie bars were noted, which indicated that a previous attempt to restrain the outward movement had been made. No significant cracking was noted. Also, a steel band to the front bay window on the first and second floors was found to be heavily corroded and delaminating.

Causation

The movement noted is progressive, attributable to historic subsidence (downward movement) compounded by outward movement due to ineffective or inadequate restraining to the main elevational walls and the bay window, allowing the brick arch to spread and drop and the brickwork above to crack.

Structural Solutions

AWT’s remedial scheme was to introduce bed joint reinforcement beaming, lateral restraints, crack stitching and resin bonded ties – adding tensile strength and restraint and thus reinstating the brickwork’s integrity and the uniformity of the wall.

After installation, pointing was raked out, reinstated and tinted to match the existing (see coloured remedial works on our proposal picture).

1. Bed joint reinforcement:
The introduction of two rows of twin cord reinforcement, forming a deep masonry beam – as indicated with red double dotted lines on our proposal images.

2. Lateral restraints:
In conjunction with the beam, 8mm stainless steel lateral restraints were introduced and screwed directly into the timber floor joists’ end grain or into the side grain, all resin bonded to the masonry – as indicated with yellow stars on our proposal images.

3. Crack stitching:
To stitch localised cracks, single 8mm stainless steel corded joint reinforcements were introduced – as indicated with red single dotted lines on our proposal images.

4. Wall ties to de-bonding brickwork:
Wherever possible, we drilled for and resin bonded 6mm stainless steel remedial ties to the centre of a brick. We then re-pointed the disturbed areas with a coloured sand and cement mixture – as indicated with blue line on our proposal plan images.

5. Making good and pointing:
We then raked out the existing mortar and repaired with new coloured sand and cement mortar to approximately 20mm in depth.

AWT operatives are highly skilled in traditional building methods and always attempt to match replacement bricks, pointing styles and mortar colour to be sympathetic with the existing building.

High Quality Structural Repairs

The photo below shows the completed structural repairs 14 years after the project was completed. Unlike the previous repairs by traditional builders, AWT’s structural repair techniques got to the root of the problem.

AWT provide long lasting, cost effective structural repairs so you can enjoy your home.

Read our frequently asked questions about bay window structural repairs.

Action Wall Ties (AWT) based in Kent are specialists in masonry reinforcement and repair covering London, Kent and the whole South East area. AWT provide professional solutions to a wide variety of structural problems. Contact us on 01227 721 255, or email us.

Edwardian bay window cracking

Edwardian round bay window cracking & dropping brickwork arches – bed joint reinforcement beaming, fenestration lintel repairs and to install resin bonded ties

The subject building is a substantial, traditionally-built, Edwardian building on two floors below a pitched tiled roof.

This period property required sympathetic treatment by Action Wall Ties’ specialised staff. Cracking and dropping brickwork was stabilised with stainless steel bed joint reinforcement and wall ties. The round structures and brick arches were reinforced and the surrounding structure made good, in keeping with the appearance of the property.

Detailed Case Study

Structural defects

Action Wall Ties investigated and reported varying stages of distortion, cracking and dropping of brick arches, along with some cracking to the brickwork above, together with many previous attempts of repairs to the round bay windows.

Causation

Action Wall Ties reported that the movement noted was believed to be progressive due to a combination of ageing, seasonal moisture, thermal expansion and contraction (i.e. hygrothermal) resulting in ineffective support from the existing arches allowing the brick arch to spread and drop, allowing the brickwork above to crack.

Solution for the structural repairs

A long term, cost-effective solution was provided by Action Wall Ties’ highly skilled operatives. The existing appearance of this period property was carefully maintained. The works were designed to minimise disruption to the building’s occupants and minimise any impact on the environment.

Our remedial scheme involved introducing bed joint reinforcement beaming, fenestration lintel repairs and to install resin bonded ties to reinstate the uniformity of the wall and provide restraint.

As indicated with red double dotted lines on our proposal 1 and 2, we introduced two rows of twin stainless steel corded joint reinforcement, forming a deep masonry composite beam all around the bay.

As indicated with green parallel lines on our proposal 1 and 2, to the underside of the fenestration openings head we drilled for, and installed, either grouted or driven 9mm helical stainless steel pins through the brick arch and passed them into the line of the deep masonry beam installed within the existing masonry.

As indicated with red stars on our proposal 1, we drilled for, and resin bonded, new 9mm stainless steel remedial ties and re-pointed disturbed areas.

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 and defects. Contact us on 01227 721 255, or email us.

1930s Purpose Built Library

1930s Public Library

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.

Library c2 300x225 - 1930s Purpose Built Library

Library C1 300x225 - 1930s Purpose Built Library

Library c3 300x225 - 1930s Purpose Built Library

Library c4 300x225 - 1930s Purpose Built Library

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.

1980s Office Building with Failing Brick Slips

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.