Parkstone House, Poole
In January 2022 Bell Group, working in partnership with Avison Young, were awarded the 2nd phase of works to carry out window replacement, roofing works and concrete repairs to the exterior of Parkstone House, a building used to home NHS staff. All works were carried out on behalf of Sovereign Housing Association. The building measures 120m perimeter x 9 elevations x 34m high x 13 stories.
The Challenge:
The scaffolding element was split into three phases and although working within a busy environment the first two phases were relatively straight forward with much of the scaffolding being grounded. However, on Phase 3 we had to produce a solution to provide access above a fragile flat roof covering the hospital library. The conventional solution would have been to penetrate the flat roof and erect supporting towers within the library and beam between the towers to enable the erection of 13 lifts of scaffolding above. Although the normal method, in this scenario it would have meant the closing of the library and removal of the flooring within the library to create a foundation to support the significant leg loads, at the same time as weather proofing the building and making good afterwards, a costly and highly disruptive operation that would have delayed the project and added huge inconvenience to all parties.
The Solution:
Ideal Scaffolding (Southern) Ltd. came up with a proposal to anchor all scaffolding to the building by creating a series of cantilevers bolted to the facade with no grounded legs. The purpose was to spread the load evenly across the building using shear plates bolted to the wall. Ideal engaged with Russell Marlow of Optima Scaffold Designs LLP who started working through the loads required from the shear plates along with frequency of ties and required platform widths and calculated we would require 2.75kN of pull out and 4.53kN of shear per tie. The total load was to be distributed over 20 shear plates per lift x 2 bolts per plate x 11 levels = 220 plates and 440 bolts in total.
The first box was ticked, however the next challenge was to prove the concrete panels we were fixing to could support the loads. After a bit of head scratching, we proposed using industrial hanging scales and testing by fixing plates to the panels from the grounded scaffolding, then attaching to beam work and testing the panels to loads greatly exceeding that required. We now needed an ambitious civil engineering company who would approve and develop our testing as we basically planned to pull the concrete panels from the building.
Via Optima we found just that company in JDL Consultants Ltd who bought into our idea, so the die was cast and on the 21st of June 2022 along with the Ideal team and Paul Meredith from JDL, we successfully tested various panels around the building to loads vastly exceeding the requirements.
Everybody has been brilliant from Optima and JDL, who bought into our vision along with the Bell Group, Avison Young and Sovereign Housing who have all been essential in allowing us to try something new and to deliver a successful project.
We have called it “THE IDEAL CANTILEVER” and hopefully it will prove a useful solution to overcome similar access challenges within our industry.
The Design:
In order to meet the brief, and with no viable options of supporting traditional beam-work, the method of support chosen for this scaffold is far from the usual with each lift self-supporting and negating the need for any supporting standards other than to carry the edge protection. Specialist knowledge provided by JDL was crucial to justify the integrity of the panels and devise a safe testing method and although the frequency of ties were greater than the norm, this was far outweighed by the benefits for the project as a whole.
Optima and JDL are both very proud to be working with this project alongside Ideal Scaffolding (Southern) Ltd., demonstrating a passion for innovation and safety.
Please get in touch if you too have a project you would like Ideal Scaffolding (Southern) Ltd. to help with.
