Cracking brick balustrade walls to walkway & Balconies Archives

Hazardous Masonry on Grade 2 Listed Building

Listed Building with Bulging & Cracking Masonry

This Grade II listed building in Thanet, Kent, was built in the 1840’s. The owners of this period property were facing the prospect of demolition and rebuilding of the facade of the property due to serious structural defects. Previous repairs using standard building techniques had failed to solve the structural problems. The property is currently in use as a nursery school. The business would have been forced to close for several months during traditional building works. AWT were able to repair the severe structural problems in a couple of weeks and preserve the period features without disrupting the running of the business.

The Structural Problem

The structural issues with this Victorian, Grade 2 listed property in Ramsgate, Kent were becoming hazardous due to the risk of falling masonry. Traditional building methods would have required several months of expensive and messy deconstruction and rebuilding work. The business would have been forced to close during the building works and the subsequent re-plastering and redecoration.

The front of the building had clearly visible bulging and cracking to the head of all the first floor windows. There were also cracks in the brickwork and stucco works each side and to the underside soffit of the window opening heads. There were clear signs of previous attempts at repairs that had failed to get to the root cause of the problems.

grade 2 listed structural defect - Hazardous Masonry on Grade 2 Listed Building — Buckling Brickwork

As shown in the photo below, the mild steel embedded within the masonry had corroded and the rust caused it to expand to several times the thickness of the original metal. The heavily corroded wrought iron arch bars were lifting and cracking the brickwork and the decorative stucco around the windows. The stucco stringer course frieze and cornice of the parapet wall was also cracking and distorting. Previous attempts at repairs had provided a temporary, cosmetic repair but had failed to solve the underlying structural defects.

The continued expansive corrosion of the wrought iron arch bars would, without remedial works, lead to the failure of the masonry and the risk of detached masonry falling from the building. Urgent structural repairs were required.

Rusting wall bars 300x225 - Hazardous Masonry on Grade 2 Listed Building

Rusted metal grade2 listed 300x225 - Hazardous Masonry on Grade 2 Listed Building

The Structural Repair Solution

Structural repairs to listed buildings need to be handled carefully to preserve the period features of the building. AWT have many years of experience working on listed properties. AWT can help the owners of listed buildings to navigate through the process of obtaining permission for repair works.

The specialist tools and techniques that AWT employ allow structural repairs to be made without the need for visible fixings. Using custom designed drilling and cutting tools, AWT can remove corroded metal fixings and embed new stainless steel fixings within the masonry.

In order to allow the business to remain open during the structural repair works, AWT arranged for the scaffolding to be erected at the weekend while the nursery was closed. The scaffolding was then double boarded and netted for safety. The AWT crew accessed the scaffolding from the side of the building allowing parents, children and staff to access the building as usual through the main entrance.

vertical wall ties 225x300 - Hazardous Masonry on Grade 2 Listed Building — Preparing Vertical Wall Ties

grade 2 listed structural works 225x300 - Hazardous Masonry on Grade 2 Listed Building — Drilling for Vertical Wall Ties

The AWT team used their specialist techniques to form composite beams within the existing brickwork and then remove and replace the corroded wrought iron arch bars. The team then reconnected and reinforced the brickwork above the windows and the parapet wall. They also repaired the cracked decorative stucco.

Before metal grade2 listed 225x300 - Hazardous Masonry on Grade 2 Listed Building — Before – Cracks & Broken Bricks

replacement lintel Thanet Kent 225x300 - Hazardous Masonry on Grade 2 Listed Building — During – Lintel Replaced

After metal grade2 listed 225x300 - Hazardous Masonry on Grade 2 Listed Building — After – Ready to Paint

This project required a combination of:

Bed joint reinforcement beaming
Grout tie injection
Resin bonded ties
Cintec sock anchors
Removal of corroded mild steel arch bars
Replacement arch bars
Brickwork repairs

The team at AWT strive to make all works as sympathetic as possible with the existing masonry. Not only do they try to match replacement bricks and pointing for colour and style they even match the mortar mixture texture.

The high quality fixings used by AWT combined with their thorough knowledge of structural defects ensures a long term solution to structural issues.

Action Wall Ties are structural repair contractors with the specialist skills required for listed buildings. AWT work along with property owners, architects, project managers and local authorities to preserve historic buildings.

AWT are available for large and small projects in Kent, London, Essex, Surrey and Sussex. To arrange a survey or to discuss project details, please use our contact form, email us or call us on 01227 721 255.

1930s style low-rise apartment blocks

1930s style low-rise apartment blocks in London

An estate of 1930s style low-rise blocks of apartments with defective balustrade walls (half-brick thick) to access deck and private balconies – AWT’s remedial scheme – remedial restraint posts, removal of the existing reinforcing rebars.

The subject buildings are 1930s style low-rise blocks of apartments, conventionally built of solid brickwork and concrete floors, with open access decks and private balconies.

Structural Problems

• Visible cracking and previous repairs (in a similar pattern) were noted to the balustrade half-brick thick walls.

• Generally the brickwork and pointing was found to be in good condition, with little spalled pointing and bricks noted. Previous repairs to the access decks and private balconies balustrade half-brick thick walls in a similar pattern were noted.

• All access decks and a representative sample of private balcony balustrade walls were inspected and scanned, locating the reinforcing bar position. Some bars were uncovered, inspected and photographed. In the main, previous repairs correspond to the pattern of the existing reinforcing bars.

• The reinforcing bars uncovered were the old ½ inch rebar bent up from the concrete slab and built into the centre of the brickwork up to, and possibly into, the cast in-situ concrete coping.

Discussion

The existing half brick balustrade walls contained mild steel reinforcing bars. From our investigations it was apparent the damage to the brickwork (cracking/spalling/previous repairs) resulted from the expansive corrosion of these bars which reduced the effectiveness of the bar, especially at the asphalt tuck line leaving the wall vulnerable to failure represent a safety issue.

The reinforcing bars viewed had corroded, delaminated and expanded, rendering the bars ineffective. The half-brick thick balustrade wall’s stability is dependent on the reinforcing.

Wrought iron decorative panels, built in lugs viewed, assessed to be corroded, delaminated and expanded, lifting and cracking the brickwork.

Stuctural Repair Solution

AWT have previously successfully completed remedial schemes to ameliorate similar defects at many other blocks.

AWT’s remedial scheme involved the development of methods and the design of equipment to enable us to undertake the remedial reinforcement, installing restraint posts, expansion joints, removal of the existing reinforcing rebars and thereafter make good the brickwork to the balustrade walls, to the access decks and to the private balconies.

The remedial scheme also alleviated the need for the removal and replacement of the balustrade walls, along with all the associated problems that this would have entailed for the occupants with the added benefits of a considerable cost saving and resulting impact on the environment.

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

1930s style low-rise apartments with balustrade wall defect repairs

An estate of 1930s style low-rise blocks of apartments with balustrade wall defects – corroding mild steel balusters cracking masonry to half-brick thick balustrade walls – removal of the baluster embedded into the coping stone and brickwork,

The subject buildings are 1930s low-rise blocks of apartments in London, of conventional brick and filler joists construction, with open access decks and private balconies.

The Structural Problem

Cracking and dislodging of the brickwork and coping stones to the balustrade walls of the private balconies was reported and noted.

Discussion

Action Wall Ties investigated the defects and reported that the causation was found to be due to expanding corrosion of the handrails mild steel supporting balusters built into the masonry.

The corrosion of the embedded mild steel results in the formation of ferrous oxide that expands to several times the thickness of the metal it has resulted from, thus breaking out of the brickwork splitting bed joints and lifting of the brickwork.

Structural repair solution

Action Wall Ties remediation involved cutting the baluster at the coping stone line, removal of the baluster embedded into the copping stone and brickwork, and completing repairs to the brickwork and coping stone. AWT re-drilled holes down into the walls for grout and designed all the necessary stainless steel fixing plates, thereafter welding the original baluster to a fixing plate.

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