Lower Borough Walls, Bath

OVERVIEW:

Lawson Group were awarded the project to provide licensed asbestos removal and demolition works at Lower Borough Walls in Bath. The building was an old chapel with other buildings incorporated within the building including a hairdressers and offices.

CHALLENGE

Licensed asbestos insulting board (AIB) would need to be removed in line with HSE regulations. The internal demolition would have to be carried out by hand and would be divided into three distinct sections of the site. The areas would be the north, middle and south buildings. All works would take place in a busy area of the town so consideration would have to be given to minimising noise, vibration and dust disruption to the local environment.

SOLUTION

Soft strip materials were removed from the structure in a controlled manner by carrying them out in small manageable pieces, placed into the
appropriate 40-yard waste bins and managed in accordance with the Site Waste Management Plan.

Asbestos Insulating Board (AIB) had been identified within the site so these areas were sealed off within full enclosures with air and bag locks all linked to a decontamination unit (DCU). For lower level AIB, a dust suppression solution was sprayed to accessible sides of the AIB prior to removal. It was then carefully prised from the steel pillars whilst shadow vacuuming or spraying suppression solution to ensure controlled removal. AIB boards were placed directly into waste bags or wrapped up in 1,000-gauge polythene sheeting if too large or bulky. Everything was double bagged or wrapped at this stage. Operatives accessed the high level AIB by using a small podium and used the same process as per the lower level methodology.

As panels were removed, the voids were inspected for any apertures to adjoining areas and were sealed as necessary. All visible dust and/or debris/cobwebs etc. within brickwork cavity and the enclosure were wiped clean or vacuumed using a Class H vacuum cleaner. Standard operating procedures were followed for decontamination, waste removal and four stage air clearance.

Only once the asbestos removal had been completed could the demolition works commence. This second phase would use hand demolition techniques by Lawson Group’s highly trained operatives. The North Building was the first building to be worked on. Mobile towers were first set up from the upper floors and, using a reciprocating saw, small sections of the roof were removed and carried down the stairs and placed directly into a 40-yard bin.

The internal stairs were constructed of timber and located on the west elevation and were removed by hand. The main structural demolition was completed by operatives using small hand tools.

Although part of the North building, the ground floor shopfront removal was left until the end of the entire project in order to keep the site secure. A saw cut to the east side of the building was also delayed until the end for the same reason. To complete these parts of the works, a specialist diamond driller was brought in after the structure had been assessed. Whilst completing these, Lawson Group ensured that the rest of the façade remained safely in place.

The next building for works to commence on was the middle building. Using the same technique that was utilised in the North building, the wide-spanning roof was removed in sections to prevent the structure from collapsing. To totally remove the first floor, a scissor lift was manoeuvred into position under the floor and operatives removed it by hand from the underside. The south building also needed its roof removing and using tower scaffolding, was removed the same way as the previous two buildings. Drawings were once again reviewed and walls were clearly marked as to what was to be removed and which would remain. As hand demolition of the structural walls commenced, each separate floor was assessed. Highly skilled operatives used a top down methodology and material was lowered to the ground floor using power barrows.

The basement also needed to be removed in this part of the building. This was hand dug and using a conveyor belt, spoil was moved up to the ground floor where it was transported to a 20-yard skip via small power dumpers.

RESULT

The AIB was fully removed within HSE regulations, the buildings were dismantled as per the client’s instructions with the site being successfully handed back 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.