Solution: Lateral restraints

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.

case study 572c74b2d05cb8.37806035 - Bowing gable wall 1950s style two-storey semi

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.

The Ridgeway - Bowing gable wall 1950s style two-storey semi

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.

Victorian bay window with spreading and cracking masonry

Victorian bay window with spreading and cracking masonry

A much loved family home in South East London featuring an ornate brick and masonry Victorian bay window with spreading and cracking masonry. Diamond drilling through the brick arches and injection of grouted cords and bed joint reinforcing restored the property to its former glory.

case study 56e19c1f0e8205.70489881 - Victorian bay window with spreading and cracking masonry

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

Problem – Bay Window Cracking/Dropped Arches

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

Causation

It was clearly evident that the bay window had rotated away from the main building line, owing to subsidence.

The bay window’s foundations were shallow, compared with those of the main building.

This situation had been exacerbated by the close proximity of a tall tree that was further desiccating the clay subsoil, though the subsidence was not deemed severe enough at the time to warrant underpinning.

case 39 a - Victorian bay window with spreading and cracking masonry

Bay Window Repair Solution

The bay window was tied back to the main elevation using stainless steel bed joint reinforcement and one core installed into diamond drill holes, indicated with green lines. This served also to beam up the brickwork and repair the cracking. In addition, the bay was tied back to the two floors behind to provide proper lateral restraint.

The arch was pinned up, using stainless steel pins, and resined into the brickwork above. After installation, pointing was raked out, reinstated and tinted to match the existing (see coloured remedial works on our proposal picture).

Arboricultural works were undertaken on the tree (by others), to reduce the crown and accordingly lower its water demand from the underlying clay.

Long Lasting Structural Repairs

The gallery below shows AWT’s completed structural repairs after 15 years. This is why homeowners across the SE of England can trust AWT with their period properties. Our structural repair techniques provide long lasting, cost effective repairs that maintain the beauty of period properties.

Action Wall Ties (AWT) are specialists in masonry reinforcement and repair, providing professional solutions to a wide variety of structural problems. We have many years experience working on period properties, listed buildings and heritage structures.

For expert structural repairs in London, Kent, Surrey and Sussex please contact us on 01227 721 255, or email us.

Failing and rotating Victorian pentagon bay window

Failing and Rotating Victorian Pentagon Bay Window

Unstable Victorian pentagon bay window. The masonry of this 5-sided bay window was failing and rotating. It required stabilising, realignment and reinforcement. AWT was able to restore the structural integrity of the ornate period bay window without slow and expensive rebuilding work.

case study 56e19dec9283f6.95445712 - Failing and rotating Victorian pentagon bay window

The bay window at the corner of this end-of-terrace domestic Victorian property was in danger of collapse. There was significant visible outward leaning movement and the dropping of the brickwork arches in the pentagon bay window.

The Structural Problem

This two-storey, pentagon-shaped (also known as 5 lite/5 panel/5 pane)  bay window with a brickwork crenellated parapet wall was found to be unstable. It suffered from rotational outward movement, dropping of the brickwork arches at ground floor level, and significant rotational outward movement to the masonry columns, causing spreading and dropping of the brickwork arches above, which was of great concern.

The structural defects in the bay window were having a knock-on effect on the rest of the house. Similar movement was reflected in both the front and left side elevations, with outward bulging noted and some cracking of the front ground floor arches.

The movement noted by the AWT survey team was progressive and advanced. The structural failings were attributable to ineffective, inadequate restraining to the bay window structure, This has allowed the masonry columns to bulge outwards and the brick arches to spread and drop, cracking the brickwork above and becoming unstable and in danger of collapse.

The Structural Repair Solution

Action Wall Ties proposed remedial scheme was to provide a viable repair by realignment and then introducing Bed Joint Reinforcement Beaming. Other structural repair techniques were also used including:

  • brickwork arch lintel repair
  • lateral restraints
  • special diamond drilling for grout tie injection
  • resin bonded ties

This combination of specialist structural repairs enabled the AWT team to reinstate the uniformity of the wall and provide restraint to the masonry.

We provided temporary support to the underside of the ground floor, then the underside of the first-floor window brick arches, removed debris from the cracks and deployed AWT designed and developed realigning cramping equipment to realign the masonry elements, closing open joints and returning the arches back to a more level line with the adjacent brickwork, along with the masonry columns, and into a more upright line before proceeding with the proposed drilling and reinforcing.

As indicated with red double dotted lines on our proposals 1, 2 & 3, we introduced twin 8mm stainless steel corded joint reinforcement, forming a deep masonry beam.

As indicated with horizontal green parallel lines on our proposals 1, 2 & 3 to form the beam and reconnect the bay window elevational brickwork, once the brickwork had been realigned with AWT-designed drilling equipment we diamond drilled a 20mm hole through each elevation of the bay, through the main elevational wall and chased internally into the main elevation wall, injecting a grouted 8mm helical bar.

As indicated with vertical green lines on our proposals 1, 2 & 3, to the underside of the fenestration openings head, we drilled for, and installed, grouted 8mm helical stainless steel pins through the brick arch and passed them into the line of the deep masonry beam, installing them within the existing masonry.

As indicated with yellow stars on our proposal 2, we drilled for, and screwed directly into timber floor joists, 8mm stainless steel lateral restraints, all resin bonded to the masonry.

As indicated with vertical green parallel lines on our proposals 1, 2 & 3, once realigned and columns made more upright, we drilled with specially designed drilling rigs from the top of the parapet down through brickwork and passed into the top of the masonry columns in order to inject a grouted 12mm stainless steel grip bar.

For cracked brick arches scheduled for reinforcement listed above, we raked out the existing cracked mortar and repaired it with new coloured sand and cement mortar to approximately 20mm in depth.

Action Wall Ties have developed methods and trained skilled experienced operatives to strive to finish our work to always be sympathetic to the existing structure. Where possible AWT match replacement bricks, pointing style and mortar mixture for texture and colour.

As can be seen in the gallery images, AWT’s specialist structural repair techniques were able to save this beautiful pentagon bay window. The period features were preserved. A long-lasting repair to the structure was achieved without any visible fixings and without rebuilding work.

Action Wall Ties services are available to clients in the South East i.e. in London & in Kent, Sussex & Essex. We regularly rectify problems and issues relating to cracking and movement around bay windows in properties of all ages and types.

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

Unstable Bay Window

Bay Window Cracking & Sagging After Installing New UPVC Windows

The bay windows in this London, SW2, property had become unstable due to the removal of the original timber windows for replacement double glazing installation. Problems were manifested as cracks in the plaster and brickwork. Gaps also opened up between the ceiling and the bay wall.

AWT was able to restore structural integrity to the bay window without the need for slow, costly rebuilding work. AWT provided a cost effective, long term repair with minimal disruption to the ongoing restoration project.

case study 5b62dbe93c42d4.63894392 - Unstable Bay Window
Gaps, cracks & damaged brickwork. Structural issues caused by replacing windows in period bay windows.

Common symptoms of structural issues arising from fitting replacement windows into bay windows include:

  1. Cracks in internal walls around bay window
  2. Gaps opening up between the ceiling and the bay window wall
  3. Difficulty opening/closing windows
  4. Cracks in external brickwork
  5. Bay window masonry sagging
  6. Bay window masonry leaning/pulling away from the main elevation

The Structural Problem with the Bay Window

During the refurbishment of this mid-terraced Victorian/Edwardian period property in Brixton, South West London it became evident that there was a serious structural issue with the bay windows. Cracks were radiating out from the bay window brickwork and the first floor bay window was leaning outward. Both the plaster and the brickwork showed significant cracking.

Hubert Rd defects 1 - Unstable Bay Window

 

The Action Wall Ties team quickly discerned that when UPVC windows had previously replaced the original timber sash window frames the supports afforded at the head of the bay had been removed. This had allowed the bay window to sag, drop and rotate away from the main elevational house wall.

Initially, temporary supports were put in place to the underside of the first floor front bay window masonry. This prevented further deterioration of the brickwork.

This is a common problem that AWT is called to repair. Removal of timber sash windows from a bay window often leaves the bay window brickwork without sufficient support. Structural problems with the bay window masonry may become evident during or after the fitting of new double glazed units to the bay window.

Restoring Structural Integrity to the Bay Window

Action Wall Ties’ plan involved restoring the structural strength integrity of the bay window and redistributing the load from the upper storey of the property.

Utilising our specially developed equipment, tooling, methods and skilled staff allowed the realignment of the leaning masonry. This was followed by the fabrication and installation of remedial steelwork and fixings. The introduction of bed joint reinforcement beaming, to form composite beams within the masonry, together with lateral restraints restored the structural strength, all with minimal impact on the face of the brickwork.

Action Wall Ties used bed joint reinforcement beaming, lateral restraints and grout tie injection to reinforce the masonry. Steel lintels and columns were also fitted.

Replacement bricks were colour matched to blend with the original masonry. The pointing style and mortar mixture were also designed to match the original texture and colour.

Hubert repaired - Unstable Bay Window

Action Wall Ties serve customers in SW London and throughout the South East i.e. in Kent, Greater London, Sussex, Essex and Surrey. We are often called in by homeowners encountering bay window problems following the fitting of new double glazed windows. We are experts in repairing and stabilising bay window brickwork and stonework.

Action Wall Ties (AWT) are specialists in masonry reinforcement and repair, providing professional solutions to a wide variety of structural problems including issues with bay windows. Contact us on 01227 721 255, email us or use our contact form.

Bowing and Bulging Wall

Bowing and Bulging Wall

The joint owners of this 4 storey semi-detached Victorian villas (converted into flats) reported visible bulging, dropping brickwork arches to the rear and gable solid brickwork walls and long cracks developed internally.

case study 5b62f1ba37a455.34142644 - Bowing and Bulging Wall

The Structural Problem

The Action Wall Ties surveyor inspection identified ineffective and inadequate restraining plus spreading of the of the brick arches as the root cause of the problem. This had allowed the main elevation brickwork to bulge outward and brick arches over the doors and windows to spread and drop causing the brickwork above to crack. It also caused long cracks in the internal plaster work of the flats.

Bronsbury front view - Bowing and Bulging Wall

This is a common problem with properties of this type and age. As well as damaging the structural integrity of the property it often makes doors and windows difficult to open and close as the frames are warped by the pressure of the sagging brickwork load above.

Restoring Structural Integrity

The introduction of remedial reinforcement to the masonry and lateral restraints was recommended to provide restraint and support to restore the brickwork’s integrity.

Specialist equipment developed by Action Wall Ties was used to install bed joint reinforcing beaming, stainless steel lateral restraints and pins within the structure of the property. This restored the structural integrity of the masonry without the need for any visible restraints.

The cracked mortar was raked out and repaired with new coloured sand, lime and cement mortar that was a match for the existing mortar’s colour and texture.

Action Wall Ties’ specialist knowledge allowed them to restore the property’s structural stability without the need for costly rebuilding work. Their specialist equipment also minimised the disruption for the residents.

Action Wall Ties (AWT) are specialists in masonry reinforcement and repair, providing professional solutions to a wide variety of structural problems including issues with bowing and bulging brickwork in Victorian properties. Contact us on 01227 721 255,  email us or use our contact form.

Action Wall Ties serve customers in North West London and the whole South East of England.

Rendered Victorian Terrace with Bulging and Sagging Brickwork

Victorian Terrace with Bulging and Dropping Brickwork

This Victorian terraced home with rendered brickwork in Walthamstow, East London was suffering with dropping and outward bowing of the brickwork.

case study 5ba50c25294103.83954636 - Rendered Victorian Terrace with Bulging and Sagging Brickwork

The Problem

This rendered Victorian terrace home in Walthamstow, London E17, was suffering with significant distortion of the masonry. It also had dropping and outward bowing movement of the brickwork on the upper floor.

The left hand side external brickwork had bulged outward from the centre first floor. Internal movement to the junction of the dividing wall and external wall was also noted.

If structural repairs are sought early enough, AWTs specialist repair techniques may allow for repairs without removing render/pebble dash finishes. However, due to the advanced structural issues with this property, it was necessary to remove the render.

 

barclay upper floor - Rendered Victorian Terrace with Bulging and Sagging Brickwork

The Solution

The first step, after the initial survey, was to carefully remove the render finish on the front elevation to expose the underlying brickwork. As well as giving access to the brickwork this also allowed for a secondary survey to ensure there were no further issues with the masonry.

Our remedial work included:

  • Bed Joint Reinforcement Beaming
  • Crack Stitching
  • Fenestration Lintel Repair
  • Lateral Restraints
  • Grout Tie Injection
  • Brickwork Repairs
  • Realignment and Pinning of the Coping Stones

The repair work was designed to reinstate the uniformity of the walls and provide restraint in order to restore the tensile strength of the brickwork. It was also necessary to reconnect the main elevational brickwork to the brick internal dividing and party walls.

Action Wall Ties used specialist drilling rigs that enable precision drilling. State-of-the-art stainless steel fixings were then installed within the framework of the building. These techniques have been designed to deal with the root cause of structural faults rather than just provide a short-term cosmetic fix.

Carefully matched coloured sand and cement mortar was used to make good the drill holes. As can be seen in the photo, there are no visible fixings once repair works are complete. The exposed brickwork is left clean, tidy and ready for repointing. The facade of the house can either be left as exposed brick or the render can be replaced if desired.

barclay render removed - Rendered Victorian Terrace with Bulging and Sagging Brickwork

AWT’s specialist skills allowed these serious structural faults to be repaired quickly and economically. No long and costly rebuilding work was required.

Action Wall Ties (AWT) are specialists in masonry reinforcement and repair. AWT can advise on structural repairs to properties with render, pebble dash and spar dash. We provide professional solutions to a wide variety of structural problems for home owners in East London as well as the rest of London, Kent, Surrey and Sussex. Contact us on 01227 721 255, email us or use our contact form.

Distorted Flank Wall with Difficult Access

Distorted Flank Wall with Difficult Access

This traditionally built mixed retail and domestic mid-terraced property in Greenwich, SE10, had visible bulging of the side wall.

case study 5c0669e65efd61.54833021 - Distorted Flank Wall with Difficult Access

The Structural Problem

The side wall brickwork of this property in was visibly bulging outwards. Movement was also noted within the property with some visible cracks.

The property located in South East London had retail space on the ground floor with domestic residences on the upper floors. Access to the flank wall was hindered by an abutting pitched slate roof which made access difficult.

Front elevation - Distorted Flank Wall with Difficult Access

Action Wall Ties needed to devise a structural repair scheme that would provide a lasting repair with minimal impact on the retail space, the residential space and the neighbouring properties.

An alternative to long, disruptive and costly rebuilding work was required.

Greenwich cracks - Distorted Flank Wall with Difficult Access

The Structural Repair Solution

AWT needed to ameliorate the masonry defects and add tensile strength to reinstating the brickwork’s integrity. A three pronged strategy was used:

  • Bed Joint Reinforcement Beaming
  • Lateral restraints
  • Brickwork repairs and infill

AWT used carefully designed scaffolding to access the defective masonry while taking care to protect the slate roof of the neighbouring property.

The wall contained an arched window opening that has been boarded over internally. The old sash window was removed and the opening was bricked up with colour matched bricks. Any damaged bricks were replaced.

Internally the installation of timber noggins and lateral restraints provided restraint of the lateral movement of the masonry. The stainless steel lateral restraints were screwed directly into the timber studs and then resin bonded to the masonry to provide a permanent solution to the lateral movement.

AWT used their precision diamond drilling equipment to install rows of twin cord reinforcement, forming a deep masonry beam. This redistributes the weight of the upper storeys. It also acts as a restraint to diagonal cracking and bulging.

Repointing the disturbed mortar with colour matched mortar provided the finishing touch.

AWT provide cost effective masonry repairs to customers 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.

 

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