Bowing brickwork on Victorian semi

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

case study 56e199b5a11814.78242588 - Bowing brickwork on Victorian semi

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.

case 3 a - Bowing brickwork on Victorian semi

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.

 

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.

Bowing brickwork piers and dropping arches

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

case study 56e19a0041f610.58831797 - Bowing brickwork piers and dropping arches

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.

case 8 a - Bowing brickwork piers and dropping 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.

case 8 b - Bowing brickwork piers and dropping arches

case 8 c - Bowing brickwork piers and dropping arches

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.

case 8 d - Bowing brickwork piers and dropping arches

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.

case 8 e - Bowing brickwork piers and dropping arches

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.

1950s style four-storey block of flats

1950s style four-storey block of flats

A substantial 1950s style traditionally built four-storey block of flats typical of London and Kent, with bowing cracking brickwork – remedial expansion joints to solid construction

case study 56e19a6e658079.78842111 - 1950s style four-storey block of flats

The subject buildings were substantial 1950s style traditionally built four storey blocks of flats, stepped to accommodate a sloping site.

The Structural Problem

case 17 a - 1950s style four-storey block of flats

• Visible cracking movement was noted to the front and rear elevations of each building comprising 225mm thick solid brickwork.

• The smaller of the two buildings was constructed with a central step. Cracking in line with the step was noted to the external brickwork, to the rear and to a lesser degree to the front elevations.

• The larger of the two buildings was constructed with two steps. Cracking in line with the steps was noted to the external brickwork to the rear and to a lesser degree to the front.

Discussion

The movement noted was considered attributable to seasonal moisture and the resulting thermal expansion and contraction (i.e. hygrothermal) – a predictable defect, as this large area of brickwork had been constructed without the benefit of any expansion joints.

case 17 b - 1950s style four-storey block of flats

Solution for Structural repairs

AWT completed a remedial scheme providing a viable repair through the introduction of expansion joints.

1. Flexible joints installed: We introduced crack inducement joints. With a twin diamond bladed saw, we cut a 10mm wide joint, 110mm deep, into the external brickwork between each window and thereafter installed a flexible joint – as indicated with red lines on our proposal images – all in accordance with AWT’s methods.

2. Making good: To the crack line schedule for new joints, 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.

Action Wall Ties (AWT) are specialists in masonry reinforcement and repair, providing professional solutions to a wide variety of structural problems in London and Kent on all types of properties, including Low rise housing blocks. Contact us on Canterbury 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.

case study 56e19a7884e823.25433311 - 1930s Purpose Built Library

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.

case 18 a - 1930s Purpose Built Library

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.

case 18 b - 1930s Purpose Built Library

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.

case 18 c - 1930s Purpose Built Library

2. Fenestration lintel repair:
To the underside of the fenestration openings head, we drilled for, and injected, grouted 8mm helical stainless steel pins through the brick arch, passing into the line of the composite deep masonry beam installed within the existing masonry – as indicated with green parallel lines on our proposal images.

3. Resin bonded ties:
Within the area of the beaming we drilled for (wherever possible to the centre of a brick), and resin bonded, new 6mm stainless steel remedial ties (four per square metre) above window openings, then re-pointed disturbed areas only with coloured sand and cement mortar.

After the proposed reinforcing works had been completed the windows were removed (by others) to enable the removal of the mild steel angles and making good of the brickwork.

High Quality Structural Repairs

The gallery below shows the completed structural repairs after 15 years. The repairs are as good as new.

Traditional building methods are only able to provide short term, cosmetic repairs. Our skilled structural repair specialists can identify the underlying causes of structural defects and provide long lasting repair solutions.

Councils, housing associations and other public sector organisations across the South East have turned to AWT for cost effective, long term solutions to a wide range of structural issues.

Action Wall Ties (AWT) are specialists in masonry reinforcement and repair across Kent and London, providing professional solutions to a wide variety of structural problems and issues from cracks to wall movement and window sill defects. Contact us on 01227 721 255, or email us.

Corroded mild steel cavity wall ties

Corroded mild steel cavity wall ties

An 1950s estate of street housing with corroded mild steel cavity wall ties – remedial wall tie treatment

case study 56e19c2cec4b78.12947654 - Corroded mild steel cavity wall ties

The subject buildings form an estate of terraced and semi-detached social street housing of cavity construction under pitched roofs.

The wall tie problem

The existing wall ties viewed were found to be mild steel vertical twist ties, commonly known as fishtail ties.

The galvanised coating was found to be in varying stages of corrosion, blackened with red rusting noted.

The corrosion of the embedded mild steel wall ties had resulted in the forming of ferrous oxide (rust), which had expanded to several times the thickness of the metal it had resulted from, in turn lifting and cracking the brickwork.

Remedial Wall Tie Solution

AWT completed a remedial programme providing a viable repair through the introduction of a pattern of remedial wall ties and isolating the existing ties, together with general brickwork repairs and re-pointing.

Call us for a quote for our specialists wall tie repairs, our tools and techniques allow us to complete the work quickly with a minimum of disruption and at a very reasonable price.

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

1980s Office Building with Failing Brick Slips

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.

case study 56e19e50dc7c07.67894388 - 1980s Office Building with Failing Brick Slips

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.

case 48 a - 1980s Office Building with Failing Brick Slips

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.

case 48 b - 1980s Office Building with Failing Brick Slips

case 48 b 1 - 1980s Office Building with Failing Brick Slips

case 48 b 2 - 1980s Office Building with Failing Brick Slips

case 48 b 3 - 1980s Office Building with Failing Brick Slips

case 48 b 4 - 1980s Office Building with Failing Brick Slips

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.

case 48 c - 1980s Office Building with Failing Brick Slips

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.

Seven-Storey Building NHBC Warranty Remedial Works

Seven-Storey Building NHBC Warranty Remedial Works

This seven-storey building in Croydon, South London required remedial work under the NHBC warranty scheme. This included stainless steel support angles, horizontal soft joints and Sika CarboDur strengthening carbon fibre plates.case study 56e19e6e7125e0.29228426 1 - Seven-Storey Building NHBC Warranty Remedial Works

The subject building was a contemporary designed seven-storey apartment building.

case 49 a - Seven-Storey Building NHBC Warranty Remedial Works

The Structural Problem

The building was found to be deficient from the one that had been designed and remedial works were instigated by NHBC warranty. Consulting structural engineers were engaged to design the required compliant remediation works and Action Wall Ties were engaged to undertake the works.

The Structural Repair Solution

The remedial works involved the introduction of stainless steel support angles with horizontal soft joints and Sika CarboDur strengthening carbon fibre plates to concrete beam, together with remedial wall ties and bed joint reinforcement.

We removed the external brickwork skin exposing the concrete beam and prepared the concrete surface removing any ridges with a concrete planer, cleaned and primed ready for and applied Sika CarboDur structural strengthening system 80mm strips bonded with Sikadur 30 in accordance with manufactures and AWT methods. Thereafter, we installed stainless steel support angles and reinstated the brickwork.

case 49 b - Seven-Storey Building NHBC Warranty Remedial Works

case 49 b 1 - Seven-Storey Building NHBC Warranty Remedial Works

case 49 b 2 - Seven-Storey Building NHBC Warranty Remedial Works

case 49 b 3 - Seven-Storey Building NHBC Warranty Remedial Works

AWT are structural repair contractors. We work with local authorities, housing associations, the NHBC and other organisations to provide cost effective structural repairs to both low rise and high rise blocks. Our repair techniques ensure the minimum amount of disruption to residents.

AWT are available for contracts in Kent, Sussex, Essex, Surrey and the whole of London. Please get in touch using our contact form, by calling 01227 721 255 or email us.

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.

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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