Tottenham Hale White Hart Pub, London

OVERVIEW:

The site was a former public house set on the North Island corner plot in Tottenham Hale. The building was three storeys high with a basement covering the area of the building. There was also a single-storey section of the building that adjoined the neighbouring property.

CHALLENGE

The building was of a traditional construction with brick walls under a slate roof with supporting timber rafters. The two upper floors had been used as accommodation. There was a large quantity of furnishings and rubbish left in the building, so this would need to be removed as part of the soft strip. Due consideration would need to be given to nearby businesses, residential dwellings and the busy road known as The Hale (A503). A site boundary would be required with strict controls by a dedicated banksman. Site would be accessed via access gates in the hoarding set up, as shown along station road below.

Due to the close proximity of the businesses and housing, vibration, noise and dust would need to be taken into consideration. Traffic and pedestrian routes would need to be set up using Heras fencing. Due to the building having disused drainage, there could be a risk of Weils disease. Full PPE would need to be used during the soft strip phase of the building. Toolbox talks were conducted, explaining the risk of Weils disease and how to prevent it. All operatives and visitors to the site had to adhere to strict COVID-19 rules based on government guidance.

SOLUTION

All services that fed the building were terminated. A CAT and Genny scan of the site was carried out by the demolition supervisor who had received the relevant cable detection training. All drainage that left the building was sealed off, this was to ensure that no debris could enter the drainage system and cause a blockage. Storm and foul drains, that were to be removed, were capped off at the site boundary.

Loose contents from within the structure, including furniture, appliances, and loose waste were removed by hand in a controlled manner and arisings managed in accordance with the Site Waste Management Plan. Door frames and skirting boards were removed by using bars and sledgehammers. All nails and fixings were removed from the walls.

The soft strip material was carried down from the second floor to the first floor and deposited out the window into the drop zone. The structure’s floors were cleared of general waste and debris prior to demolition. This was then removed from the building via the windows and doors that lead directly to each designated drop zone. All soft strip materials were taken away each day, by an excavator with grab attachment. This ensured that a build-up of combustible material could not occur. These materials were then segregated at site level, there were separate waste bins for general waste such as insulation material, plastics, metal, clean and dirty wood.

An excavator with a re-handle grab attachment, loaded the soft stripped material into the appropriate 40-yard waste bins, and removed from site in accordance with the Site Waste Management Plan.

Following the soft stripping, the licensed asbestos materials were removed prior to any demolition work taking place. The following Licensed asbestos had to be removed from the basement of the building:

  • Flash guards & arc shields to electrical switch gear within room B:01
  • Asbestos cement redundant drain / rainwater goods leaning on wall within room B:02.
  • Asbestos cement boards to ceiling, AC debris to floor & AC flue to redundant boiler within room (1m2) B:03
  • Small amount of AIB & AC debris to the floor within room B:06.

Removal of asbestos was carried out under semi-controlled conditions including a respirator zone, and all as per the current CAR Regulations 2012. Operatives were site-inducted which included reading the Plan of Works. Personnel decontamination procedures for transiting to and from the Respirator Zone were used.

Prior to any works commencing on site, a decontamination area was also positioned at the edge of the asbestos zone – at the top of the stairwell. Personal air monitoring was carried out during removal works and following removal works, a reassurance air test was also conducted.

Access to the low-level fascia panels and fuse box was gained from ground level. All fuse boxes were sealed with spray tac and tape before being removed whole and double-bagged. The electrical cable was also sealed with spray tac and tape before being cut and removed.

Access to the various contaminated areas was segregated by barrier tape and warning signs. Wetting was used throughout the removal process, using a water and suppressant mix via a low-pressure spray. The fascia panels were removed as whole as possible. Where screws or nails were to be removed, wetting was used throughout the process using a water and suppressant mix via a low-pressure spray. Nails were gently eased out; this continued until all the fascia panels had been removed. Where possible, the fascia panels were removed as a whole and then lowered onto the scaffold where they were double-wrapped in 1,000-gauge polythene.

The bags/wrap were then carefully wiped down and taken immediately to skip. When the fascia panel had been removed, the area was cleared and cleaned to the satisfaction of the site supervisor and an EM10 was completed. The AIB debris was treated as above and placed in a bag for disposal.

At the end of the removal, the work area (including waste route) and all the equipment were thoroughly cleaned using low-dust techniques (e.g. wet wipes, tac-rags, vacuuming with a Class H vacuum cleaner). Cleaning included all surfaces and the inside surfaces of the Respirator Zone sheeting. Special attention was given to any stripped surfaces. Any visible asbestos products or suspicious debris on the waste route were removed.

The site supervisor then proceeded into the respirator zone for final checks to ensure that the enclosure and respirator zone were ready. Only when an analyst had passed the visual and air test, did operatives proceed to take down the respirator zone and bag the 1,000-gauge polythene as waste. This was double-bagged and disposed of as asbestos waste.

Once the asbestos removal had been safely completed, then the demolition phase could begin.

All fencing carried signage, warning of the dangers that would affect others entering the demolition zone during structural mechanical demolition. The excavator’s working area was made up of an exclusion zone, with the only permitted person being allowed in to be the plant operator. The demolition supervisor oversaw the mechanical demolition from the back of the site away from the drop zone and was always in radio contact with the plant operator.

The 360-demolition excavator, with grab attachment, was positioned on Station Road. The low-level building was removed first. Starting with the boundary wall, a pulveriser attachment was used to reduce the height of the wall down to ground level.

Once a section of wall had been removed (approximately 2 metres-wide or between two windows), the concrete roof was removed back to the internal wall. The concrete from the roof was allowed to safely drop to ground level. A dust boss was used during this process to ensure dust levels were kept to a minimum.

As the demolition progressed into the low-level buildings, items such as window frames and radiators were removed and stockpiled using the grab attachment. The concrete from the roof was spread out to create a working platform for the excavator to sit on.

Due to the close proximity of the neighbouring Premier Inn building, hand separation of the boundary wall was carried out.

A double width tower, with a platform height of 1.2 metres was set up next to the wall on firm level ground. A Scaff tag was attached to the tower and inspected by a PASMA trained site supervisor. The tower’s out riggers were set up correctly and checked during inspection. Using a sledgehammer to loosen the bricks, works then started on the top course. Working horizontally, the bricks were lifted down from the wall and removed to ground level. Care was taken to remove the wall and not to damage the Premier Inn’s wall. If possible, plywood sheets were slid in between the Premier Inn wall and the wall that was being removed. After this was completed, the mechanical demolition of the main structure could commence.

Using a hydraulic grab attachment, the brick wall was removed down to the first floor starting at the top of the gable wall. As the roof was removed, the timber joists were lifted out and stockpiled away from the working area. The roof was then removed back to an internal wall. The excavator then removed the 2nd floor, all floorboards and joists were lifted out together and stockpiled.

The side wall of the building was then removed. The scaffold that was located around the building Using a hydraulic grab attachment, the brick wall was removed down to the first floor starting at the top of the gable wall. As the roof was removed, the timber joists were lifted out and stockpiled away from the working area. The roof was then removed back to an internal wall. The excavator then removed the 2nd floor, all floorboards and joists were lifted out together and stockpiled.
The side wall of the building was then removed. The scaffold that was located around the building was then removed by the appointed contractor. During this process no mechanical demolition took place until the scaffold had been removed down to the next agreed point with the site supervisor, plant operator and scaffold contractor.

An area was created next to the front of the site for the scaffold to be placed. This area was fenced off and only scaffolders were permitted to be there. The excavator then proceeded to remove another bay of the roof back as far as it could reach. The floors below were then removed.

As works progressed into the building, the walls were removed using the grab attachment down to ground level, care was taken to ensure the excavator did not track over the basement until it had been filled in with hardcore. The hardcore was also used to gain height and create a working platform. The ground floor of the building was pushed into the basement, all hardcore was left within the building footprint to fill in the basement, this enabled the excavator to gain height.

All general waste and wood products were segregated using hydraulic grabs and stockpiled, then loaded into the bins as works progressed. As the mechanical deconstruction of the building moved forward, a dust boss was moved along ensuring all areas were covered and no dust was being generated. Once all waste had been processed and removed from the building, the slab of the low-level building was cleaned off using a grading bucket.

Following this, all arisings from the building were removed from site and the floor slab was wetted and swept clean.

An excavator, with bucket attachment, then proceeded to lift the slab starting at the edge of the site. The slab was broken into pieces no bigger than 500cm wide. When required, a breaker attachment was used on a second excavator to achieve this.

The slab was stockpiled on the footprint of the building ready for removal from site, eight-wheeled lorries were directed into the site by the appointed banksman. Each lorry was then positioned in the loading area. As the slab was removed, it was loaded into the lorries. When safe to do so, each lorry was directed from the site loading area on to the main road through the access gate located off Station Road.

The foundations of the building were then lifted out to a depth of 500mm below the existing ground level and stockpiled ready for breaking. The area of ground from where the foundation had been removed was then backfilled and tracked in. This process was repeated until all foundations had been removed. The foundations were broken using the hammer attachment, into pieces no bigger than 500cm wide. The walls of the basement were reduced in height to 500mm below existing ground level. The basement slab was punctured using the breaker attachment into one-metre squares.

The basement was then backfilled in 150mm layers. Crushed material was brought into site and tipped out into the loading / unloading area. Using a bucket attachment, the excavator spread the crushed material inside the basement to a layer of 150mm thick. A ramp was made into the basement (with bulk timber edge protection installed) to enable access for the roller. Each layer was well compacted, the roller was then removed from the working area and another layer installed. This process was repeated until the level matched the rest of the site.

RESULT

The site was successfully cleared of asbestos, demolished and handed back to the client ready for the next stage of development.

To find out more on how Lawson Group can help with your next demolition or asbestos removal project, call 01793 782000, email enquiries@lawsongroup.co.uk.