Lateral restraints Archives - Page 3 of 4

Distorted Columns & Lintels

Failing Bay Window Columns & Lintels

The charming bay window of this period property in Kensal Green, North West London was at risk of collapse due to failing lintels and stonework columns following the addition of a loft conversion.

The Structural Problem

The structural problems of this period property in London, NW10 were clearly visible. There was significant outward rotation of the masonry columns and lintels around the bay window. The structural issues had become more noticeable following the addition of a loft conversion and the installation of new double glazed windows.

The survey by AWT revealed that if the columns and lintels were not restrained and reinforced it would result in the failure of the bay window masonry. Such a serious defect required specialist structural repairs to avoid costly and disruptive rebuilding of the bay window.

NW10 BAY COLUMNS AFTER 225x300 - Distorted Columns & Lintels — After: Columns aligned.

The seriousness of the problem can be seem by how far the bay window masonry was leaning away from the main structure. The photo below shows that a gap of several centimeters had opened up between the new double glazing and the original stonework. This outward movement had also caused cracking in the surrounding brickwork.

NW10 Bay window gaps 1 225x300 - Distorted Columns & Lintels — Before: Large gaps between masonry & double glazing.

NW10 Bay window gaps repaired 225x300 - Distorted Columns & Lintels — After: Masonry flush with double glazing.

The Structural Repair Solution

Avoid costly rebuilding work by calling in the experts. At best, traditional building methods would require the partial demolition and rebuilding of the bay window brickwork. This would be costly, disruptive and time consuming. At worst, homeowners may find they have paid for superficial, cosmetic repairs that do not solve the underlying structural issues.

The front of the house was stabilised by realigning, restraining and reinforcing the masonry using AWT’s specialist tools and techniques. This included:

Bed Joint Reinforcement
Lateral Restraints
Grout Tie Injection
Brickwork Repairs
Repairs to Ornate Columns
Repointing with Colour Matched Mortar

All of this was achieved without visible fixings or rebuilding work. The property was left simply requiring retouching of the paint in the disturbed areas to restore it to its original beauty.

NW10 Bay window gaps 2 300x225 - Distorted Columns & Lintels — Before: Large gaps around windows.

NW10 Bay window gaps repair 300x225 - Distorted Columns & Lintels — After: No gaps around windows.

AWT provide cost effective structural repairs for a wide range of structural issues including failing bay window columns and lintels. We operate not only in NW London but across the whole of London and 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.

Failing Timber Bressumer Lintel

Collapsing Bay & Gable

This period property in Hampstead, North West London had significant structural defects due to a failing Bressumer beam over the bay window area. The entire bay window area and the decorative gable wall above was leaning away from the main structure. Without professional structural repairs, this would result in the ultimate failure and collapse of the structure.

The Structural Problem

This front elevation of this home in London, NW3 was at risk of collapse. The first floor timber Bressumer beam over the bay window was failing, causing the downward movement of the central column of brickwork. This resulted in significant distortion to the window cills, lintels and first floor causing them to lean down to the centre of the building.

This type of horizontal wooden beam is known by a number of different names including:

Timber lintel
Bressumer or Bressummer
Breastsummer
Summer Beam
Various other spellings including Sommer, Somer, Sommier and Somier

This type of substantial wooden beam is often found in period properties over bay windows supporting the building above and above shop windows.

Victorian timber Bressumer beams over bay windows are generally over stressed compared to modern day standards. They are often affected by Creep with significant deflection together with further deterioration of the timber due to rot, damp, pest infestations etc. This can render the beam ineffective, deflecting the brickwork above, as well as the floor and the ceiling, requiring remediation. Another common cause of Bressumer beam problems is movement within the building’s structure which leaves the beam lacking adequate support.

Many of the common symptoms of a failing timber bay window beam were clearly visible including:

Significant deflection of the beam
Cracking, bulging brickwork above
Masonry leaning away from the main elevation
Cracking internal plaster
Bulging ceilings
Sloping floors
Bowing of the main roof
Distorted window cills
Distorted window lintels

The entire bay window and the decorative gable brickwork was at risk of collapse. Traditional building methods would have required substantial and costly rebuilding work. Without AWT this would have required a major building project to de-construct the front elevation down to the Bressumer beam, replace the beam and thereafter rebuild the front first floor brickwork complete with window cill, lintels, refitting the windows and replacing internal plastering and finishings.

AWT was called in to stabilise the structure and preserve the period features. AWT’s specialist tools and structural repair skills enabled them to restore structural integrity without the need for rebuilding work, saving time, money and disruption.

NW3 bressummer repaired 300x225 - Failing Timber Bressumer Lintel

NW3 bressumer 300x225 - Failing Timber Bressumer Lintel

NW3 bresummer 300x225 - Failing Timber Bressumer Lintel

The Structural Repair Solution

AWT used specialist equipment to realign the masonry, replace the wooden Bressumer lintel with a steel beam and install restraints. A lateral gable beam was also installed, the bulging gable wall was realigned and the structural integrity was restored.

Traditional building methods often provide a superficial, temporary solution. AWT’s structural repairs get to the root cause of the structural failings.

The structural repair works included:

Installation of temporary supports
Removal of failing Bressumer beam
Installation of new steel Bressumer lintel
Installation of lateral gable beam
Realignment of masonry by 70mm using hydraulic equipment
Bed Joint Reinforcement
Lateral restraints
Re-pointing disturbed areas with colour matched mortar

The remedial works restored the leaning masonry to its vertical alignment and restrained it from leaning outwards. The new steel Bressumer beam, lateral gable beam and the Bed Joint Reinforcement within the masonry restored the strength of the structure.

AWT provided a permanent solution to the structural defects without the need for expensive rebuilding work or visible fixings.

NW3 new bressumer 300x225 - Failing Timber Bressumer Lintel

NW3 new bressummer 300x225 - Failing Timber Bressumer Lintel

Hampstead bressummer repaired 300x225 - Failing Timber Bressumer Lintel

NW3 bressummer support 1 300x225 - Failing Timber Bressumer Lintel

Hampstead bressummer repairs 1 300x225 - Failing Timber Bressumer Lintel

Hampstead bressumer repairs 1 300x225 - Failing Timber Bressumer Lintel

Satisfied Customers

The first photo below shows the re-plastered ceiling ready to be repainted and the second shows it after redecoration was completed. The beautiful period features of the house can be enjoyed in their former glory.

The home owners were delighted with how hassle free the process was and at the finished results.

Some of their comments were:

“You managed to diagnose pretty much what was wrong over the phone without having seen a photo i.e. Bressumer beam failure. We felt we were dealing with a professional company with a real idea of what we would need.”

“Your surveyor, Scott, was again reassuring. He gave the impression that whilst our house was of concern it was nothing compared to some properties you’ve repaired and it wouldn’t be beyond you.”

“Once we agreed to go ahead you were again very supportive and we felt comfortable and confident that we were in good hands.
The building team you that sent us were very reassuring and immediately had our confidence. The entire team were polite and professional and inspired confidence.”

“My elderly neighbour 2 doors away asked me when the works were starting and I was happy to tell her they were already finished….”

“We have a family friend that was very concerned with us walking blindly into a massive building program with no clue as to what we were doing and that it could all go horribly wrong. I’ve been very pleased to let him know everything went better than expected and AWT completed the works quicker than we hoped. It’s all been a very positive experience.”

AWT provide cost effective structural repairs for a wide range of structural faults including failing wooden beams and lintels. We operate not only in NW London but across the whole of London and the South East of England.

Read our frequently asked questions about bay window structural repairs.

Stone Arch & Bay Window Reinforcement

Reinforcement and Repair of Ornate Stone Arch & Bay

This end of terrace home in Walthamstow, East London had 2 structural issues. The stone entrance arch had significant cracking to the brickwork above and cracking in the internal walls. The ornate bay window was dropping and leaning outwards plus the stonework was cracking and spalling.

The Structural Problem

The period decorative features on this home in London, E17, were showing their age due to structural issues causing cracked brickwork and stonework. The structural movement had exacerbated the deterioration of the paintwork leaving the beautiful, ornate stonework looking shabby.

There was significant cracking above the stone entrance arch in both the external brickwork and the internal walls.

The bay window had visibly shifted and caused cracks in the external brickwork as well as in the interior walls. The supporting columns and cills had become distorted.

These are common problems in such Victorian / Edwardian properties and are usually the result of ageing and inadequate restraining in the original building methods.

The AWT team also had to be prepared in case the masonry components weren’t solid masonry but simply a thin facade covering a timber frame.

Walthamstow brickwork repairs 230x120 - Stone Arch & Bay Window Reinforcement

Walthamstow stoneworkwork repairs 230x120 - Stone Arch & Bay Window Reinforcement

E17 stone repairs 230x120 - Stone Arch & Bay Window Reinforcement

The Structural Repair Solution

Installation of temporary supports & AWT designed cramping equipment
Realignment of masonry with hydraulic jacks
Precision diamond drilling & installation of stainless steel corded joint reinforcement.
Reconnecting the bay window brickwork to the main elevation by embedding grouted 8mm helical bars.
Installation of lateral restaints.
Repair damaged stonework with Flexcrete Monomix concrete repair mortar system.
Crack stitching work to cracked brickwork.
Cutting back damaged brick faces or resurfacing damaged bricks where possible using AWT methods.
Cutting out badly cracked bricks and replacing with colour matched yellow stock bricks.
Re-point disturbed areas with colour matched sand lime and cement mixture.

AWT provided an efficient, cost effective, permanent repair without the need for visible fixings. AWT have the tools and skills to remediate the root cause of these types of period property structural defects. AWT’s specialist fixings meant no rebuilding work was required and so disruption to the homeowner was kept to a minimum. The property was left ready for painting to restore it to its former glory.

Read our frequently asked questions about bay window structural repairs.

For a fast, effective solutions to stone arch and bay window structural problems contact AWT today. We provide professional solutions to a wide variety of structural issues for home owners across London, Kent, Surrey and Sussex. Contact us on 01227 721 255, or email us.

Repairing Gaps Around Bay Window Glazing and Distorted Gable Brickwork

Repairing Distorted Gable Brickwork & Large Gaps Around Bay Window Glazing.

The masonry of the bay window of this property in London E11 was leaning away from the main structure. Large gaps were opening up between the bay window frames and the double glazing units. Realignment of the sagging bay window plus reinforcing failing gable brickwork to restore structural integrity were required.

The skills of the AWT team allowed them to restore the structural integrity in a cost effective and efficient manner without any rebuilding or visible fixings.

The Structural Problem

This East London home had visible cracking in front bay window brickwork and stone lintels. Outward rotation of the first floor bay window was clearly visible. Large gaps had opened up between the bay window frame and the glazing. The cracking and distorting of the masonry bay had caused significant movement to the brickwork gable above.

Problems of this type are common in such Victorian / Edwardian properties and are usually the result of ageing and inadequate restraining in the original building methods.

The AWT also had to be prepared for the possibility that the masonry components might not be solid masonry but simply a thin facade covering a timber frame.

The Structural Repair Solution

After the initial inspection, the AWT team conducted an intrusive survey by drilling carefully placed inspection holes and using an endoscope where necessary. This allowed them to determine that this property’s bay window was constructed using solid masonry elements.

The first element of the structural repairs required the installation temporary supports to the underside of the first floor bay window lintels. AWT designed realigning cramping equipment and hydraulic powered jacks were used to realign the columns and brickwork ready for reinforcing.

Specialist drills were used to introduce rows of 8mm stainless steel corded joint reinforcement fixings. This redistributed the upper storey load to the supporting structure below and restrained the diagonal cracking and bulging tendencies.

Precision drilling rigs were used to install helical stainless steel pins through the brick arch. Resin bonded stainless steel pins were used to reconnect the brickwork to the main body of the building.

Internal gable restraints were fixed in place. Stainless steel lateral restraints were installed directly into the timber joists and resin bonded to the masonry. This restored the structural integrity of distorted gable brickwork.

Any disturbed mortar was re-pointed with mortar matched for colour and texture to blend with the existing pointing.

Read our frequently asked questions about bay window structural repairs.

For a fast, effective solution to bay window structural problems contact AWT today. We provide professional solutions to a wide variety of structural problems for home owners across London, Kent, Surrey and Sussex. Contact us on 01227 721 255, or email us.

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.

Bowing brickwork on Victorian semi

Victorian mid-terrace house rear addition bowing and dropping brickwork – stabilisation, bed joint reinforcement beaming, crack stitching, fenestration lintel repair, grouted tie and lateral restraints

The subject building was a traditionally built Victorian mid-terrace domestic residence, consisting of three floors below a pitched tiled roof.

Problem

Signs of distortion and distress, with localised cracking, were noted to the far external gable wall of the rear addition – along with cracked and dropped brick arches to the first and second floor level. Previous repairs of old tie bars with patress plates, large steel straps, rebuilding and re-pointing were noted, indicating a history of movement.

A significant outward bulge to the side elevation at first floor level with localised cracking was also noted, as was significant downward movement at the rear doorway with all brickwork leaning towards that point.

Causation

The movement noted was attributed to subsidence, which may well be historic as internal redecoration shows no sign of cracking. Under these circumstances we did not consider that underpinning was warranted at this stage. Our pragmatic solution was to reinforce and tie back the building by using a combination of bed joint reinforcement and lateral restraints into the first floor construction to reinstate structural integrity.

Solution

AWT’s remedial scheme was the introduction of bed joint reinforcement beaming, crack stitching, fenestration lintel repair, grout tie injection and lateral restraints – 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.

1. Reinforcement:
We introduced two rows of twin 8mm stainless steel corded joint reinforcement to form a deep masonry beam – as indicated with red double dotted lines on our proposal images.

2. Grout tie injection:
We drilled into the party wall and bent into the hole one of the grouted 8mm stainless steel cords – as indicated with red stars on our proposal images.

3. 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 and passed into the line of the deep masonry beam installed within the existing masonry – as indicated with green parallel lines on our proposal images.

4. Crack stitching:
We stitched localised cracks with the introduction of single 8mm stainless steel corded joint reinforcement – as indicated with red single dotted lines on our proposal images.

5. Lateral restraints:
In conjunction with the beam, we introduced 8mm stainless steel lateral restraints 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.

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.

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.

Bowing brickwork piers and dropping arches

Victorian two-storey bay window with bowing brickwork piers and dropping arches – realignment, bed joint reinforcement beaming, lateral restraints, reinforcement to the brickwork columns and grout ties and concrete repairs to masonry cill

The subject building was a traditionally built mid-terraced domestic Victorian/Edwardian house in South London on two floors below a pitched tiled roof.

Bowing brickwork piers and cracking, dropping and sagging of the structure around the bay window required urgent attention. Using equipment and methods designed by Action Wall Ties, the bay window was reinforced and repaired.

Detailed Case Study

Defect

Action Wall Ties’ investigation reported distortion and distress with localised cracking to ground floor, external spandrel brickwork and cracking and dropped key stones to the brick arches.

The slender brickwork columns to the ground floor had bowed outwards leaving a bow shaped space between the timber box window frame and the brickwork column that has been repeatedly re-pointed.

The bay window has a very large overhanging cill with supporting corbelled knees.

Causation

Action Wall Ties reported that the movement noted was considered to be progressive due to a combination of ageing and ineffective restraining of the slender brickwork columns and rotational effect of the overhanging cills, causing the bowing out of the columns and the arches to spread, crack and drop – cracking the supported spandrel brickwork above.

Structural repair solution

Our remedial scheme involved the introduction of bed joint reinforcement beaming, lateral restraints, reinforcement to the brickwork columns and grout tie injections, together with concrete repairs to masonry cill, all to reinstate the uniformity of the wall and provide restraint.

We provided temporary support to the underside of the ground floor brick arch key stones, removed the debris from the cracks and lifted the stones/arch back into a more level line with the adjacent brickwork.

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

As indicated with green parallel lines on our proposal 1, the beam reconnected the bay window elevational brickwork, and this was accomplished with AWT designed equipment enabling us to diamond drill through each elevation and chase into the main elevational brickwork and install a grouted helical bar.

The formation of continuous beams within the existing masonry should redistribute the upper storey loads, to a large extent, to those parts of the supporting structure, below which are best able to carry them while at the same time assisting in restraining diagonal cracking and bulging tendencies.

As indicated with yellow stars on our proposal 1, in conjunction with the beams, we drilled for, and screwed direct into the timber floor joists, 8mm stainless steel lateral restraints – all resin bonded to the masonry.

As indicated with green parallel lines on our proposal 1, to assist in alleviating the rotation affect from the large cills we installed grout ties vertically, drilling for and injecting a grouted 8mm helical bar.

As indicated with blue parallel lines on our proposal 1, we introduced a purpose fabricated steel reinforcing post, fitted and fixed to the inside of the brickwork columns, fixed with stainless steel resin bonded fixings.

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

Victorian mid-terrace bay window repair

Victorian mid-terrace house bay window generic repair. Victorian mid-terrace house – Generic subsidence and cracking bay window repair

This building was a traditional two-storey mid-terrace domestic residence of Victorian vintage with a pitched tiled roof.

Problem – cracked bay window

The front bay windows showed visible distortion and distress, accompanied by significant cracking to both the main brickwork and brick entrance arches, which had also dropped.

Causation – subsidence

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. 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.

Read our frequently asked questions about bay window structural repairs.

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

Bowing gable wall 1950s style two-storey semi

1950s Semi with Bowing Gable Wall

Bowing gable wall to a 1950s style semi-detached house in Sittingbourne, Kent. Remedial wall ties, isolating the existing ties, bed joint reinforcement beaming, crack stitching and lateral restraints.

The subject property in Swale, Kent, comprised a 1950s style two-storey semi-detached house of cavity brickwork construction.

Problem – Gable wall bowing & cracking

The gable wall: The right side gable wall had a visible outward bulge at the centre of the wall at first floor level and significant cracking was noted (no corresponding internal cracking was present). The front elevation external skin was rebuilt after suffering damage in a hurricane. No downward movement at DPC level was noted.

An AWT investigation with a metal detector and an endoscope revealed that the wall ties viewed to the right side gable wall and rear elevations were mild steel vertical twist ties, all in a similar heavily corroded condition and showing signs of de-laminating.

Horizontal cracking, lifting and opening up of joints were noted at irregular intervals on the right side and rear elevations, with corroding ties clearly visible.

Discussion

Right side elevations: We believed that the movement was progressive, due to ineffective and/or inadequate restraining, and not attributable to significant subsidence.

Wall ties: Our opinion, in accordance with the Building Research Establishment’s recommendations, was that the symptoms noted above were likely to be representative of the majority of the cavity wall ties to the right side, and the main rear elevation suffering from corrosion.

It was believed that the building’s right side and main rear elevation would benefit from remedial wall ties and the isolation of the existing ties.

Structural Repair Solution

AWT completed a remedial scheme providing a viable repair by introducing remedial wall ties, isolating the existing ties, then employing bed joint reinforcement beaming, crack stitching and lateral restraints.

Remedial wall ties and isolation of existing ties: Our operatives undertook remedial wall tie treatment to the right side and main rear elevations in accordance with AWT’s wall tie treatment – Generic Repair.

Bed joint reinforcement beaming: The introduction of two rows of twin 8mm stainless steel corded joint reinforcement forming a deep masonry beam – as indicated with red double dotted lines on our proposal plan.

Crack stitching: We stitched localised cracks with the introduction of single 8mm stainless steel corded joint reinforcement – as indicated by red single dotted lines on our proposal.

Lateral restraints: At approximately 900mm centres we drilled for, and screwed directly into alternate timber floor joist’s end grain or into the side grain, 8mm stainless steel lateral restraints into the timber floor and ceiling joists, all resin bonded to the masonry along with corresponding wall ties – as indicated with green stars on our proposal plan.

Make good the pointing: To the cracking schedule for reinforcement listed above, and to areas of weakness to pointing to the right side elevation, we raked out the existing cracked 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.

Homeowners, landlords, housing associations and councils across Kent, London, Surrey and Sussex can call on AWT’s experts to repair rusting wall ties and other structural problems. Action Wall Ties (AWT) are specialists in gable wall repairs, masonry reinforcement and repair. We provide professional solutions to a wide variety of structural problems. Contact us on 01227 721 255, or email us.