Metro Bank, Wolverhampton

OVERVIEW:

Lawson Group won the contract to convert three retail units into one, located at One Queen Street, Wolverhampton; creating a space ready for development into a new branch of Metro Bank.

CHALLENGE

The fronts of the units were located in a main shopping area of Wolverhampton, to the rear of the site was a service yard which was restricted by a canopy that measured 12ft in height. On both sides of the site were shops that would remain in use for the duration of the works. Being in a very busy town centre location would mean major consideration would need to be given to noise, dust and vibration. AIBs would need removing from two of the existing retail units.

All vehicles would need to be removed from the front of the site by 9:30am, so meticulous planning would be required. Each shop unit had a large quantity of furnishings and shop fittings inside them and these would need removing during the soft strip process. The building was to be taken back to the bare structure, this would include any floor coverings, plasterboard and wood fixings. This structure was three storeys in height, with various internal brick and block walls that divided up rooms and units – these would also need to be removed. As part of the works, all the shop fronts were to be removed including the front cladding. Access scaffold would need installing along the front of each unit. Located outside each unit, at first floor level, was a reinforced concrete canopy; this needed to be removed along with areas of the floor slab and supporting steel beams. An appointed structural engineer confirmed which beams and floor slabs were to be removed and if any temporary works were required.

Scope of Works for this project therefore included:

  • Site inductions
  • Soft stripping
  • Waste removal
  • Reinforced canopy removal
  • Cladding and shop front removal
  • First floor slab and beam removal
  • Internal removal of brick and block walls
  • Asbestos removal
  • Demobilisation

SOLUTION

Loose contents from within the structure, including furniture, appliances and loose waste were removed by hand in a controlled manner, arisings were managed in accordance with the Site Waste Management Plan. Door frames and skirting boards were removed using bars and sledgehammers. All nails and fixings were removed from the walls, avoiding areas that had AIBs. Electric scissor lifts were used to gain access for removal of the ceilings, and all the M&E from the ground floor. These were cut out using a reciprocating saw and removed from the working area. In preparation for the waste removal, the front windows of the shop were removed in two locations – on the upper floors. Using a bar, the beading around the edge of the glass was removed and glass taken out. Once each of the two panes of glass had been removed, a reciprocating saw was used to cut out the frame of the window. The area was then boarded over, using plywood, by screwing to the frame and attaching warning signs.

Due to the location of the building, the waste bins were located inside the hoarding at the front of the site, these were loaded by hand. All materials from the basement and ground floor were carried into the bin using the shop doors for access. All soft strip materials were stockpiled at the front of each shop ready for removal. These waste materials were then segregated at site level, with separate waste bins for general waste such as insulation material, plastics, metal, clean and dirty wood. Material from the second and first floors were removed via the windows at first floor level.

A forty-yard bin was positioned directly under the loading point, beneath the concrete canopy, with chapter eight barriers positioned around the bin. During waste removal from the first floor, two operatives were issued with full restraining harnesses. The demolition supervisor ensured that the one-metre long lanyards were secured to the anchor points around the window frames. Both the operatives then moved out onto the canopy, the full restraining harnesses ensuring the operatives were restricted to only one metre from the window. All soft strip material from the first floor was passed to the operatives next to the windows, the material was lowered into the bin. All soft strip material was removed each day to ensure a build-up of combustible material did not occur.

Next to be removed was the reinforced concrete canopy. Plywood sheets were positioned under the canopy to protect the pavement area. Two MEWPS were positioned between the hoarding and canopy with a three-metre-long section of Monarflex, in-between and supported by each MEWP. This acted as a protection screen that extended two metres above the canopy during its removal and was moved along as works progressed.

A cut line in the canopy was made one and a half metres from each of the neighbouring shops. A Lawson Group operative, using full restraint harness and anchored to a designated point, used a T1000 hand breaker and disc cutter to create this 300mm wide gap in the canopy. This was the starting point for the remote controlled Brokk. The Brokk was position under the canopy whilst the operative stood behind the machine in a safe position away from the drop zone.

Using a hydraulic sheer attachment, the canopy was removed. During the works, the dust was controlled by using a water supply from the building. The concrete was allowed to safely drop to ground level. When safe to do so, operatives then cleared the material and heaped it up ready for removal. A disc cutter was then used to cut out any remaining re-enforcing bar. The hardcore was loaded into a one tonne hi-tip dumper, the material was then loaded into twenty-yard bins ready for removal from site. As works progressed, the MEWPs along with the protective Monarflex barrier, moved along the working area. Once the canopy had been completely removed, the edge of the concrete was trimmed back using a disc cutter and handheld breaker. This was all inspected to ensure all the loose hanging material had been removed.

Access scaffold was then positioned around the building by the appointed contractor. The scaffold was fully boarded with sheeting fixed to the outside to fully enclose the works. Starting at the top, all timber cladding was cut out and removed using a reciprocating saw, the material was then passed to an operative inside the building at each floor level.

All concrete panels and cladding were broken out using handheld T750 breakers. The waste material was then cleared away using wheelbarrows and stockpiled in areas on the first floor ready for removal from site. As works progressed down the front of the building the steel beams were exposed. The shop fronts at ground level were then removed; all glass, doors, frames, cladding and signage were removed. Using a disc cutter and reciprocating saw, the material was cut into small sections. The waste from this process was removed each morning via the waste bins located at the front of the site.

Asbestos Containing Materials were located within two of the three retail units, so these would need removing before any internal demolition could take place. AIB identified included:

  • Former well-known mobile phone provider store – 147m2 of AIB ceilings.
  • The Bag Shop – 1m2 AIB header panel.

AIB ceiling panels were located on the second and third floors of the phone provider store and a header panel within the stairwell between the ground and first floor of The Bag Shop. A DCU was set up, connected to the building and made operational; enclosures were also formed. DCU, airlocks and bag locks were positioned as per the site plan.

The DCU was positioned within the loading bay area located to the rear of both shops, direct connection was not possible due to the configuration of the building. Designated waste and transit routes were set up to the DCU and waste skip. Respirator only warning signs were displayed to ensure other occupants were aware of ongoing asbestos removal works.

Removal of AIB ceiling panels – former mobile phone provider store

Second floor canteen area

A scaffold crash deck (access platform) with HAKI type staircase was positioned within the kitchen canteen area on the second floor of the former mobile phone provider store. This was to allow for the removal of AIB ceiling panels from above the stairwell, that connected the second to the first floor.

First and second floor canteen, kitchen, female and male toilets, and offices

Where required, Lawson Environmental operatives worked from podium steps or mobile access towers during the removal process. A team of two worked together in the enclosure during removal works.

Where the tiles were supported by a frame, the surface of each tile was vacuumed to remove any loose fibres. Using a low-pressure sprayer, the tile was wetted on the underside and was gently removed from its support whilst direct vacuuming was carried out. Once lowered, the panel was further wetted and placed into red asbestos waste bags. AIB tiles were removed from the perimeter of the ceiling first to expose any inaccessible voids above the ceiling line. Inaccessible voids were then sealed up as work commenced until the perimeter tiles had been fully removed and sealed up. Panels were removed by hand whilst shadow vacuuming and spray suppression was carried out by the second operative.

Any visible dust, debris or cobwebs in the exposed void or other surfaces were wiped clean or vacuumed using a Class H vacuum cleaner. The remaining boards were removed in a sequential manner. The boards were screwed into metal framework, so this framework was also removed as contaminated waste. Any MMMF insulation in the ceiling void above was sprayed with surfactant and double-bagged for disposal as contaminated waste.

As tiles were removed, an operative sprayed the rear of the panels with surfactant ensuring all of the exposed surfaces were fully wetted to avoid any dry spots. A handheld pump sprayer or Greco was used for this purpose. The remaining ceiling tiles were removed one at a time. Each tile was carefully removed using the shadow vacuuming process. One operative held the tile whilst the other vacuumed both front and rear surfaces prior to removal. The pre-cleaned tile was then lowered down and placed into a red asbestos waste bag. Once safely within the bag, an operative wrapped cloth tape around the top of the bag to seal it.

The sealed waste bag was then carefully lowered down from the tower to another operative at ground level, the waste was then stored within the enclosure in readiness for removal at the end of the shift. Bagged asbestos waste was removed from the enclosure via a dedicated bag lock, all as per the removal of asbestos waste regulations.

Removal of AIB door header from within staircase – The Bag Shop

Removal of AIB door header panel was needed, as there was insufficient room to position a bag lock, then the waste bag was removed via a preformed air lock. The header panel was located above the access stairs from the ground to first floors within the Bag Shop. To gain full access to the header panel, one operative worked from the stairs within the preformed enclosure. The door header panel was screwed in and all screws were visible. These were removed using hand tools and in conjunction with using shadow vacuum procedures (LEV).

Once the door header panel had been released, an operative lowered one side in order to make the back of the tile accessible for decontamination. The back of the panel was carefully vacuumed prior to carefully applying an application of fibre suppression mix and then was lowered horizontally. It was then placed into a red asbestos waste bag, sealed with silver cloth tape and put neatly to one side until ready to be removed from the enclosure. After the door header panel had been removed, the timber frame was sprayed with surfactant. This was also removed and placed into red asbestos waste bags, then disposed of as contaminated waste. Following removal of the AIB Header Panel, standard operating procedures for decontamination, cleaning down and air testing of the enclosure were followed.

After the AIB removal, the internal work could progress, initially by removing internal walls in the basement, ground, first and second floors along with various concrete staircases. As work was taking place in a confined area, and a powerful machine was needed, then Lawson Group utilised a remote controlled Brokk 90 excavator. The floor slab loading was checked to ensure it could take the loading of a Brokk 90 by the appointed engineers. Chapter eight fencing was installed around the working area to create a drop zone. Starting on the ground floor, the walls were removed using a breaker attachment. Work started at the top course and the wall was removed down to slab level. As it was removed, the hardcore was cleared to ensure that no excess weight built up on each slab. The hardcore was then shovelled in to a one-tonne dumper, which in turn moved the material to a twenty-yard bin located in the loading area. The Brokk was then positioned in the basement, all walls were then broken out using the method described above. It was then used to remove the concrete stairs. Using the hammer attachment, the concrete was broken out in strips. Once the entire flight had been removed, the hardcore was shovelled on a conveyor which had been installed from ground floor to the basement and was used to remove all the material from the basement to ground floor level. A scaffold ramp had been installed from the basement to the ground floor to enable the Brokk to be removed. The ramp was also used to support the conveyers for hardcore removal.

The first floor was the next destination for the Brokk, where all the internal walls were then broken down. As they were removed, the hardcore was removed using wheelbarrows. The slab was also removed by the Brokk, ensuring it was positioned over a steel beam for support. Scaffold edge protection was installed by the appointed contractor before the slab was opened. A drop zone had been created at ground floor level using chapter eight fencing with warning signs attached. At all times the Brokk operator was positioned behind the edge protection, if he had to enter the working area then a full restraint harness was used and anchored to the appropriate anchor points. The Brokk started at the farthest point, which was the front of the building, working back, each bay of slab was broken out. All the beams were cleared of all concrete. Once the area of slab had been broken out, the hardcore was cleared from the ground floor using a series of conveyor belts which transported it to a twenty-yard bin positioned outside at the rear of the building.

Throughout the building there were various concrete stairs to be removed, this was also carried out using the Brokk. It was positioned at the top of each flight of stairs with acrow props installed under each flight that was being removed. The Brokk broke out the flight in strips exposing the reinforcing bar. The reinforced bar was then cut using a disc cutter. All concrete was then removed and tipped into a twenty-yard bin for removal using the same conveyor belt system as mentioned before.

Prior to removing any steel beams, the weight of each beam was calculated by an appointed structural engineer. Two Genie lifts were positioned at each end of the beam to be removed and positioned under it. An operative gained access to the side of each beam by using a scaffold tower. Using a propane cutting torch, a drop cut was made to each end of the beams, each beam was then lowered to ground level and cut into one-metre sections which were then removed from site

RESULT

All three former units were safely transformed into one larger retail unit, on time and ready for the next phase to turn this building into another branch of Metro Bank.

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.