Defect: Defects to heritage structures

Collapsing Grade II Bay Window Repairs

Grade II Listed Building Bay Window Saved From Collapse

AWT was contacted by very concerned homeowners of part of a Grade II listed c 1800 farmhouse with several structural engineers’ reports stating the bay window was unstable and that rebuilding was the only recourse, but that was contrary to Historic England’s preferred solution and their wishes.

The double bay window was supported with props to prevent collapse. In common with many properties that AWT repairs, this property showed signs of previous ineffective structural repair work.

AWT was able to realign and reinforce the structure without the need for pattress plates, tie bars or other visible reinforcement. AWT’s specialist structural repair techniques also allowed the owners to avoid slow, expensive and inconvenient deconstruction and rebuilding of the ground floor bay to install new lintels. AWT’s specialist repair techniques were classed as a repair by Historic England which greatly simplified the entire process.

Read our frequently asked questions about bay window structural repairs.

The Structural Problem

When AWT was called in to repair this Grade II listed property the bay window masonry had been supported for 2 years with props to prevent collapse.

The homeowners structural engineer report had warned that the structure “could be close to the tipping point” and recommended that the ground floor bay be rebuilt and the first floor repaired. Deconstructing the ground floor masonry and rebuilding it with additional lintels would have been slow and costly, not to mention disruptive to the residents. AWT’s specialist structural repair techniques allowed the owners to avoid slow, very expensive and inconvenient deconstruction and rebuilding of the ground floor bay to install new lintels.

The owners were delighted that AWT could offer a much better solution to the property’s bay window’s many structural defects.

The structural problems included:

  • Brick arches over the ground floor windows slipped by 20-25mm
  • Brick arch nearest the left-hand brick pier pushed out by approx. 20mm
  • Fractured brickwork & mortar joints opened up
  • Pronounced, 60mm bulge in left-hand brick pier
  • 25mm bulge in right-hand brick pier
  • Cracks in brick columns
  • 650mm long crack in 1st floor internal wall
  • External brickwork movable & wall ties completely fractured
  • Ongoing movement with cracks and bulges increasing month on month
  • Collapse of outer brickwork only a matter of time

The Structural Repair Solution

AWT’s specialist repair techniques were classed as a repair by Historic England which greatly simplified the entire process.

AWT, adopting their uniquely developed realigning equipment, was able to lift and realign the original structure’s fabric, therefore, conserving the original features and textures. Despite the advanced nature of the bay window defect, only the outer layer of the brick columns required deconstruction and rebuilding with new handmade shaped brickwork (the original bricks were too decayed to be used.)

As can be seen in the gallery below, the doors and windows remained in situ throughout the work, keeping the disruption to the homeowners to a minimum.

AWT works realigned and reinforced the bay window, reinstated stability and maintained the appearance without the need for pattress plates, tie bars or other visible reinforcement.

Hydraulic realigning equipment, designed by AWT,  was used to lift and realign the arches and brickwork before reinforcing the masonry. Using AWT’s specialist drilling equipment, stainless steel fixings are installed within the masonry. This strengthens the structure and redistributes the load from the upper-story masonry. The hidden fixings and remedial wall ties also restrain the brickwork from bulging.

The reinforcement work included:

  • Bed Joint Reinforcement – Beaming
  • Fenestration lintel- brickwork arch repair
  • Precision Diamond drilling
  • Lateral restraints
  • Grout tie injection
  • Location and isolation of corroded wall ties
  • Remedial, resin-bonded wall ties
  • Deconstruction & rebuilding of just the outer skin of the bay pillars
  • Brickwork repairs and repointing.

Action Wall Ties are specialist structural repair contractors with the skills and experience required to repair Grade I, Grade II and Grade II* listed heritage buildings.  AWT work along with property owners, structural engineers, 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.

Grade 2 Listed Gable Stabilisation in SW London

simple horizontal - Grade 2 Listed Gable Stabilisation in SW London
geograph 3281453 by David Anstiss - Grade 2 Listed Gable Stabilisation in SW London
Dutch gable ornate - Grade 2 Listed Gable Stabilisation in SW London
gable repair plans 2 - Grade 2 Listed Gable Stabilisation in SW London
listed building stone repairs - Grade 2 Listed Gable Stabilisation in SW London
ornate gable repairs - Grade 2 Listed Gable Stabilisation in SW London
Grade II Listed Dutch Gable Repairs
Ornate Stone Dutch Gable Repairs
Structural Repairs for Grade II Gable
Structural Repairs for Victorian Dutch Gable
Victorian Gable Wall Repairs
 
simple horizontal - Grade 2 Listed Gable Stabilisation in SW London

Repairs to Failing Grade II Dutch Gables

Kingsway Square in Battersea, South West London is a Grade II listed building, formerly known as Mountfield Mansions, it formed part of Westminster College. Designed by E. W. Mountford in the late 1800s, it is an impressive building packed with architectural details.

The Victorian era Dutch gables, composed of red brick and ornate stonework were structurally unsafe and at risk of collapse. A sympathetic structural repair solution was required that could restore structural integrity without compromising the beauty of the facade.

The Structural Problem

Inspection of the Dutch gables walls that feature in this grade 2 listed building revealed that they had failed structurally. The masonry could be manually rocked and was leaning and at risk of collapse. Cracks were evident in the gable masonry and stonework. The masonry of the gable walls required urgent realignment and strengthening.

Traditional building methods would require deconstruction and rebuilding each gable wall. This would obviously have entailed substantial inconvenience to the residents as well as additional costs for internal redecoration. A cost-effective, long-term structural repair was required.

Due to internal concerns, one of the residents also required a tailor-made solution that used exterior steel fixings.

As with many buildings that AWT is called in to repair, there was evidence of previous structural repairs. Patress/anchor plates were visible on the brickwork but they had failed to address the root causes of the unstable gable masonry.

The Structural Repair Solution

AWT provided a bespoke structural repair solution to reinforce the gable walls. AWT’s unique skill set and proven experience were invaluable on such a delicate project.

The consulting structural engineers recommended the most appropriate remedial solution would be to install Cintec anchors vertically through the top of the stone and extending at least as far below the rafter line as the stonework extends above it.

A custom diamond drilling rig was required to allow precision drilling through over 3m of stone and brickwork at the apex of the gables. The Cintec sock anchors were then installed.

Cintech sock anchors consist of a stainless steel rod in a mesh sleeve. The anchor is installed deep into the masonry by the use of precision drilling techniques. The sleeve is then filled with a specially designed cementitious grout. This provides a mechanical and chemical bond between the masonry and the anchor that restores structural strength. The small diameter drill holes required for Cintech sock anchors are filled with color-matched mortar to provide a virtually invisible repair.

In contrast to long, drawn-out rebuilding work, Cintech sock anchors provide a highly efficient repair method. This technology also removes the need to use visible fixings such as pattress/anchor plates.

Four lateral restraints were also installed on each side of the gables to restore structural integrity and restrain the masonry. These stainless steel lateral restraints screw directly into the timber rafters and are resin bonded to the masonry to provide a long-lasting structural reinforcement of the gable walls.

Special Request Alternative Repair Solution

For the resident that requested exterior steel fixings a bespoke, Y-shaped frame was fabricated. This was fitted out of sight, to the rear of the gable masonry, ensuring it did not interfere with the lightning conductors on the gable.

The AWT team carefully cut away the protruding moulding at the rear of the gable to provide a flat surface. The bracket was then fixed in place with stainless steel resin bonded fixings. The finished repair provided a long-term structural repair without compromising the beauty of the Victorian gable masonry.

AWT provides cost-effective structural repairs for a wide range of structural issues. Our specialist repair techniques make us the ideal choice for projects involving listed and heritage buildings. 

We work together with structural engineers, architects and project managers to find economical and effective solutions. We operate not only in London but across the whole of the South East of England.

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.

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.

Thanet grade 2 listed - Hazardous Masonry on Grade 2 Listed Building

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.

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.

Scaffolding listed building repairs - Hazardous Masonry on Grade 2 Listed Building

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.

 

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.

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.

Edwardian Stucco column remediation

London Edwardian Stucco column remediation

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

case study 56e199f6b5d7f7.59403455 - Edwardian Stucco column remediation

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.

case 7 a - Edwardian Stucco column remediation

case 7 b - Edwardian Stucco column remediation

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).

case 7 c - Edwardian Stucco column remediation

case 7 d - Edwardian Stucco column remediation

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.

case 7 e - Edwardian Stucco column remediation

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.

Grade 2 listed building remedial reinforcing

Grade 2 Listed Building Remedial Reinforcing

Grade 2* listed Spa Green Estate in London EC1, designed by Bertholt Lubetkin. Extensive remedial reinforcing including work to the hit and miss vents, brick slips and widespread brickwork repairs.

case study 56e19bd4a80183.85880495 - Grade 2 listed building remedial reinforcing

Spa Green Estate is a public housing estate in central London designed by Bertholt Lubetkin and Grade 2* listed in 1998.

It is widely viewed as being the finest example of public housing of its type, but remedial works were required and Action Wall Ties were engaged to undertake elements of the project.

Extensive remedial reinforcing was required including work to the hit and miss vents, brick slips and widespread brickwork repairs.

case 32 a - Grade 2 listed building remedial reinforcing

AWT operatives were made aware of the importance of the buildings and accordingly ensured that all works were carried out with the appropriate level of care and respect for the structure, and were completed to be sympathetic with the Grade II* facade all to the approval of English Heritage.

case 32 b - Grade 2 listed building remedial reinforcing

Long Lasting Structural Repairs

The After photos in the gallery below shows the building 14 years after the work was completed. This shows the quality of workmanship provided by AWT.

Action Wall Ties (AWT) are specialists in masonry reinforcement and repair, providing professional solutions to a wide variety of structural problems on Grade 2 Listed Buildings in Kent, Surrey, Sussex and London. Contact us on 01227 721 255, or email us.

Terracotta Facade Bowing Out

Terracotta Facade Bowing Out

East Ham Town Hall in East London. Main terracotta facade bowing out – precise drilling deep into the building and installation of Cintec anchors

case study 56e19be036cf66.29626384 - Terracotta Facade Bowing Out

East Ham Town Hall, in the E6 area of London, is an important landmark building, and its hundred year old brick and ornate terracotta construction requires specialised care when remedial works are called for.

LB Newham engaged Action Wall Ties to undertake reinforcing works to stabilise the important facade of the town hall. External cracking was spreading across the entablature frieze cornice above the left side entrance.

Problem – cracking and debonding brickwork

1. The main entrance – Above the staircase and to the left side of the entrance cracking was noted between the internal junction of the external brickwork, the dividing wall and the corner of the ceiling above.

2. The floor slab and ceiling – Cracking was noted on the 150mm floor slab that was found to be of a clinker rich material.

3. Brickwork – There were no signs of significant cracking to brickwork, although the movement noted was considered likely to be progressive. It was apparent that the outer brickwork was bowing outward, de-bonding from the dividing walls, and had become unconnected, cracking the dividing walls and floor slab – all reducing the restraining to the facade.

debonded brickwork bulges 1.3 - Terracotta Facade Bowing Out

case 33 a - Terracotta Facade Bowing Out

Proposed Cintec Anchor solution

Action Wall Ties completed a remedial scheme providing a viable repair by the introduction of Cintec anchors.

1. AWT entered the terracotta by diamond drilling with a narrow wall diamond core drill and retained the core to be replaced.

2. AWT then diamond drilled a 38mm × 4 metre hole through the external wall into the floor slab and the dividing wall as indicated with red crosses on the accompanying image.

3. AWT supplied and installed Cintec 40mm sock anchors with 18mm stainless steel bar, in accordance with the manufacture’s recommendations by certificated operatives.

4. The entrance hole in the terracotta was made good by the replacement of extracted core together with replacement bricks and coloured sand and cement pointing, all in accordance with AWT specifications.

Action Wall Ties (AWT) are specialists in masonry reinforcement and repair, including specialised mediums such as Terracotta, providing professional structural repair solutions with Cintec anchors to a wide variety of structural problems in London, Sussex, Surrey and Kent.  Please contact us on 01227 721 255, or email us to discuss your structural repair issues.

Cracking Museum Courtyard Walls

Cracking Museum Courtyard Walls

This Grade II listed mansion in London W1 is now a national museum housing the Wallace Collection. AWT were called in to repair cracked brickwork in the courtyard walls. The brickwork repairs on this heritage building needed to provide a cost effective, long term solution while preserving the appearance of the red brick and render walls.

case study 56e19e89742e96.25357839 - Cracking Museum Courtyard Walls

The subject building in central London, known as Hertford House, dates from the 1770s and features red brick and render courtyard walls.

case 50 a - Cracking Museum Courtyard Walls

As part of a major refurbishment cracking to the front courtyard walls was to be addressed.

Working with the main contractor and architects we proposed and completed remedial works including bed joint reinforcement, brickwork repairs and render finish repairs.

case 50 b - Cracking Museum Courtyard Walls

case 50 b 1 - Cracking Museum Courtyard Walls

case 50 b 2 - Cracking Museum Courtyard Walls

case 50 b 3 - Cracking Museum Courtyard Walls

case 50 b 4 - Cracking Museum Courtyard Walls

case 50 b 5 - Cracking Museum Courtyard Walls

case 50 b 6 - Cracking Museum Courtyard Walls

case 50 b 7 - Cracking Museum Courtyard Walls

case 50 b 8 - Cracking Museum Courtyard Walls

case 50 b 9 - Cracking Museum Courtyard Walls

AWT used their specialist structural repair techniques to restore structural integrity without the need for visible fixings or slow, costly rebuilding work. The beauty of the red brick and render finish was preserved.

case 50 b 10 - Cracking Museum Courtyard Walls

case 50 b 11 - Cracking Museum Courtyard Walls

case 50 b 12 - Cracking Museum Courtyard Walls

case 50 b 13 - Cracking Museum Courtyard Walls
Action Wall Ties are structural repair contractors with the specialist skills required for listed buildings. AWT work along with architects, project managers and local authorities to preserve historic buildings.

AWT are available for large and small projects in London, Kent, 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.

King’s Cross Station Cintec Sock Anchors

King’s Cross Station Cintec Sock Anchors

One of London’s King’s Cross station’s main entrance brick arches was sagging and losing structural integrity. AWT was contracted by Network Rail to drill for and install Cintec sock anchors to repair the structural defect.

case study 56e19eb6768176.03107812 - King's Cross Station Cintec Sock Anchors

The subject building was central London’s King’s Cross station. This Grade I listed building’s eastern large spanning brickwork entrance arch was found to be de-bonding.

debonded brickwork bulges 1.3 - King's Cross Station Cintec Sock Anchors

case 51 a - King's Cross Station Cintec Sock Anchors

case 51 a 1 - King's Cross Station Cintec Sock Anchors

case 51 a 2 - King's Cross Station Cintec Sock Anchors

case 51 a 3 - King's Cross Station Cintec Sock Anchors

case 51 a 4 - King's Cross Station Cintec Sock Anchors

case 51 a 5 - King's Cross Station Cintec Sock Anchors

Action Wall Ties was contracted to drill for, and install, Cintec cementitious grouted sock anchors to reconnect the brickwork.

This entailed drilling 75mm holes into the 225mm arched timber frame and drilling into the brickwork with a 38mm diamond drill vertically to a depth of 1200mm. We then prepared for, supplied and installed cementitious grouted sock anchors with grade 304 stainless steel M12 threaded bar washer and nut.

case 51 a 6 - King's Cross Station Cintec Sock Anchors

case 51 a 7 - King's Cross Station Cintec Sock Anchors

Action Wall Ties (AWT) are experienced structural repair contractors with the capacity to work on both large and small public sector and infrastructure projects. We can assist with a wide range of structural repairs including the installation of Cintec cementitious grouted sock anchors.

AWT are available for contracts in London, Kent, Essex, Surrey and Sussex. Please contact us via our contact form, by email or call 01227 721 255.

Structurally Unstable Period Property

Structurally Unstable Period Property

Victorian / Edwardian property in Harrow, Greater London, saved from partial demolition and rebuild.

case study 58dd0a549b8da4.65274980 - Structurally Unstable Period Property

This period property in North West London was saved from partial demolition and rebuild by our specialist structural repair techniques and solutions.

The Structural Problems

Slender brick columns between the front windows were severely bowing outwards.

The masonry above the windows was dropping and sagging. The gable wall above was leaning inwards and had started to collapse.

Bowing brick columns 4 - Structurally Unstable Period Property

There was evidence of previous attempts at repairs by traditional builders.

The building had been deemed structurally unstable and was unoccupied. Standard building contractors has proposed demolishing the affected areas and rebuilding. This process would be lengthy and costly.

Demolition and rebuilding would have destroyed much of the ornate brickwork and altered the character of the property. A partial rebuild of the property would also have entailed removing all the internal finishings from the affected areas which would add to the costs.

Click on the gallery below to see how far out of alignment the brick columns were.

The brick columns around the windows of this Victorian / Edwardian property had rusting metal fixings within the brickwork. This is a common cause of cracking and bowing in brickwork.

The slender support columns were visibly bowing causing structural instability in the brickwork above.

The brickwork of the gable above was leaning in and was only being held in place by the internal roof rafter. Some of the brickwork had collapsed inwards leaving a hole in the wall.

Apex 4 - Structurally Unstable Period Property
After

Structural Repair Solution

Specialist equipment designed by Action Wall Ties was employed to firstly retain the columns to allow the removal of the corroded fixings and debris then realign the columns back to inline before installing new stainless steel fixings to reinstate the structural integrity of the masonry.

Specialist hydraulic rams developed by Action Wall Ties were used to gradually realign the thin brickwork columns. Custom made stainless steel fixings were then installed to strengthen and stabilise the masonry.

Replacement bricks, where necessary, were colour matched to the existing bricks. In areas where the mortar was disturbed repointing was carried out using colour matched mortar.

Long Lasting Structural Repairs

The precisely targeted repairs carried out by Action Wall Ties preserved the decorative brickwork of this Victorian / Edwardian property. The repair works were substantially cheaper and faster than the proposed rebuild. In contrast with rebuilding, the precision techniques used by Action Wall Ties left the internal finishings of the property virtually unscathed.

Action Wall Ties offer structural repair services to period properties for clients in the South East – in London & in Surrey, Kent, Sussex & Essex.

Action Wall Ties (AWT) are specialists in repairs to period properties with bespoke solutions avoiding the need to demolish and rebuild. We also offer professional solutions to a wide variety of structural problems. Contact us on 01227 721 255, or email us.

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