Brickwork repairs & repointing Archives - Page 4 of 4

Harrow High School. Corroded Window Arch Bars

Harrow High School. Corroded Window Arch Bars.

As can be seen in the photos, there were cracks in both the external brickwork and the internal plaster work around the windows of these school buildings in Harrow, Greater London. In places the external brickwork was crumbling.

The Structural Problem

The brickwork above the windows was visibly lifting and cracking. An inspection by Action Wall Ties quickly identified the cause as corroding mild steel arch bars which were reducing the support from the existing lintel arrangement. This type of fault also results in difficulties with opening and closing windows.

The flat brickwork arches in the building were of differing ages but all were built on mild steel arch bars. As these bars had rusted the resulting ferrous oxide (rust) expanded to several times the thickness of the original metal in turn lifting and cracking the brickwork above. In places the facing brickwork had crumbled to reveal the metalwork.

The Structural Repair Solution

The remedial works were designed to add tensile strength and reinstate the brickwork’s integrity without detracting from the appearance of the building.

The brickwork openings required remedial support and the arch bars needed to be removed to stop any further damage to the building. Bed joint reinforcement and beaming fenestration lintel repair techniques were used to restore the tensile strength of the masonry.

Bricks were carefully removed to allow the cutting and removal of the corroding arch bars. Two rows of twin 8mm stainless steel corded joint reinforcement fixings were installed forming a deep masonry beam. The formation of continuous beams within the existing masonry redistributes the upper storey loads and assists in restraining diagonal cracking and bulging.

Specialist drilling rigs were used to drill for and install helical stainless steel pins through the brick arch and into the line of the deep masonry beam that had been installed within the existing masonry.

Where possible the existing bricks were reused. Replacement bricks were colour matched to blend in with the original brickwork. The cracked mortar was raked out and repaired with new coloured sand and cement mortar to match the existing mortar.

Action Wall Ties serve customers not only in the Harrow area but throughout the South East i.e. Kent, Greater London, Sussex, Surrey and Essex.

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

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.

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.

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.

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.

Bulging and Cracking Ornate Bay Window

This Victorian/Edwardian terraced home in Lewisham SE4 was suffering with structural defects that were causing cracks in the decorative work around the bay windows as well as bowing brickwork.

The Structural Problem

The beautiful decorative moulding around the bay windows of this terraced home in South East London was cracking. Even more worryingly, the brickwork of the bay window was visibly bulging and rotating away from the main part of the house. Inside the house there were cracks appearing in the internal party wall.

Action Wall Ties were called in to find a permanent solution to the structural issues while preserving the period features of the property.

The Structural Repair Solution

The AWT’s survey team diagnosed inadequate restraint of the bay window and a point loading issue with the party wall. Reinforcement of the masonry and a redistribution of the load on the party wall was required.

AWT have an arsenal of techniques at their disposal that are not available to traditional builders. This allows them to repair structural defects without rebuilding works.

Following a thorough survey, the following techniques were selected to restore the structural integrity:

Bed Joint Reinforcement Beaming
Crack Stitching
Grout Tie Injection
Lateral Restraints
Concrete and Brickwork Repairs

The specialist tools and equipment developed by AWT allows them to repair structural defects without compromising the look of a period property such as this.

A twin diamond bladed machine with attached vacuum was used for precision drilling prior to the installation of rows of twin 8mm stainless steel corded joint reinforcements. This helped to redistribute the weight of the upper storey to those parts of the supporting structure best able to carry them. It also assisted in restraining diagonal cracking and bulging.

8mm stainless steel lateral restraints screwed into the floor joists’ bresummer beam and resin bonded to the masonry provided further lateral restraint.

Localised cracks in the brickwork were stitched together using stainless steel fixings embedded out of sight within the brickwork.

Any patches of defective masonry were cut away and the areas were repaired using Flexcrete – a specialist repair substrate.

The finishing touches included colour matching any replacement bricks and ensuring the pointing style and mortar mixture matched the existing texture and colour.

AWT’s specialist skills allowed these serious structural faults to be repaired quickly and economically without damaging the character of the period features.

Action Wall Ties (AWT) are specialists in masonry reinforcement and repair. We provide professional solutions to a wide variety of structural problems for home owners in Lewisham and the whole 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

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

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.

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.

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.