At The Stonemasonry Company Limited we pride ourselves on our ability to be flexible, adapting to any scenario or space in order to achieve the best results for our clients. Although we have written in the past about our cantilever stone staircases no two are ever the same. Our work at Egerton presented us with a number of challenges, both in terms of space and design parameters and ever-changing logistical considerations, making this a great example of how a variety of challenges can be overcome to produce beautiful results.
This 6 flight cantilever stone staircase, with fully cantilevered solid stone landings, was manufactured in Tunisian Limestone, rising 7 levels though a series of obstacles including window openings, lintels as well as transitions between structural and non structural walls and unseen steelwork. All of these elements, required individual attention from our design team, in terms of both aesthetics and engineering practicalities. When you add these elements in to a project that features an irregular shaped stairwell, without a straight line in sight, it made the perfect project to challenge our team.
From the below image you can appreciate how the staircase seamlessly flows over, under and in some cases, even straight across all the windows and returns into the wall it cantilevers from. Where the stair goes across the window you can see how a portion of steps are floating in mid air. It was only through the perfect understanding of the geometry of these treads, and an in depth engineering analysis, that it was possible for us to carefully place concealed steel bars in each tread connecting them all together, making them act as one piece that bridges both halves of the staircase flight from either side of the window.
The solid stone landings that feature in this project are a beautiful element of the design. As well as increasing the head height as you transition up and down the levels they also create an uninterrupted flow of stone that completely integrates the stairwell. The stone landings cantilever off the wall and connect back to steel supports on each of the main landings, offset from the stairwell footprint. However these beautiful elements presented some logistical challenges, given their size transport and delivery, as well as the lifting and fitting sequence, required a great deal of care and attention, making these pieces an impressive feat in themselves.
While discussing fitting, it’s important to mention that this staircase was installed out of sequence. Usually we build from the lowest flight upwards, on this occasion however, due to program restrictions, we were required by the contractors to fit from the ground floor upwards and then return to install the two basement flights at a later point. This change required a lot of careful considerations, so that we could adapt our gantry and lifting process as we were installing our heavy equipment only inches away from the perfectly finished flight of stone steps above. We then had to feed the rest of the staircase, tread by tread, through the stair void, whilst ensuring that the completed elements were in no way impacted by this installation. Although this is not our recommended method of installation, as there was no other option, our team did all they could to accommodate this change without compromising on finish, with amazing results.
In addition to the challenges posed by the fitting schedule, landings and floating elements that we overcame in this project, we also faced the requirement to extend stone treads to find structural walls, we also engineered special lintels to go above and below certain windows and devised a special template system in order for our installation team to be able to set out all six flight perfectly. Lastly we also delivered and fit a large amount stone flooring in other areas of the property.
We never cease to be amazed by how many challenges can arise with a traditional cantilever stone staircase, but we are just as amazed and impressed by how our teams overcome every hurdle in front of them. It is safe to say that no two projects are ever the same and although some have more obstacles than others at The Stonemasonry Company Limited we relish these opportunities to develop our knowledge and explore what is possible with stone. This enables us to produce staircases like this, which we absolutely love! Our feature staircases stand as a testament to the blood sweat and tears that go into our work, and this staircase in particular was absolutely worth it.