Q&A: Our Past, Our Future, Our Present—Roundtable Discussion with Stone Industry Experts
Our Past, Our Future—Our Present is an online roundtable discussion from our “Stone is Structure” webinar, where stone experts explored and weighed in on stone—as an element used primarily as a means of transferring load (other than self-weight), through the structure. The conversation that followed discussed topics relevant to our AEC industry, and touching on different areas of the design and construction process, such as: structural stone design, its sustainability factor and what we can do to overcome any construction challenges.
Speakers: + Mike Picco, President, PICCO + Steve Webb, Co-founder + Director, Webb Yates + Bryan Thorburn, Director of Business Development–Europe & Middle East, Polycor
Moderated by: + Karl Doucas, Principal VP Operations, PICCO
The following is a transcript of the discussion, which has been edited for brevity and clarity.
Q: Why is NOW the right time for structural stone design disruption or rediscovery?
A: Steve Webb—I think that the wide and broad adoption of steel and concrete as a solution in the 1930s for building, really, was based on the ideas that we were going to have limitless energy. People were seeing endless oil reserves, nuclear power…all kinds of stuff. The notion that there’ll be no limitations on energy. Clearly, there is now a real limitation on energy and a real drive for sustainability, so using the materials that are right under the ground is part of the solution for that. I think it’s wrong that stone is left behind as building material. But I also think this issue of sustainability really puts stone back on the agenda.
Karl Doucas—Steve made some great points related to sustainability and how to really view stone and carbon footprint; the small carbon footprint.
Q: How does sustainability factor when the use of stone at structural dimensions, often means using significantly more stone than traditional rainscreen or thin panel facade applications?
A: Bryan Thorburn—The black bars that Steve showed in the slide where you see the carbon footprint vs. tensile strength of the material shows it very well. The more stone that goes into the building means less concrete and steel that goes into the building. So, you have a far less embodied carbon in the building itself; in the actual material it’s going in. The other factor is the longevity of the building. I mean, buildings are now set to survive 50 years. In many parts of the world there are buildings now that are two, three thousand years old built in stone (maybe that’s the extreme). Of course we’re not building for 3,000 years; but, we certainly see that the durability and the resilience is very important. Especially right now with ideas of fire resistance and flood resistance. All of these factors ticks all the boxes in terms of the longevity and the lack of the very, very low carbon use in it.
On the other side, as you have more stone and less of these super airtight insulated greenhouses we've built that need to cool; and needed a lot of energy for air conditioning. All of those arguments the concrete industry talks about, in terms of thermal mass of the operational energy of a building, is super important when it comes to the stone itself. We think about those beautiful mediterranean homes that stay cool even on a hot day. And it’s because of the thermal mass—it breaks that curve of having to add more energy for the cooling and air conditioning, and that’s maybe a challenge we have of this becoming more accepted in terms of being the norm. But what we do know, is a thermal wall of a thick stone wall, for example, is going to help in terms of cooling. And I guess the reason that we’re here talking about this is because it’s not getting cooler. It’s because of rising temperatures. So, I would say that you’ve got the embodied carbon and the operational carbon between both of them.
Karl Doucas—They’ve all shown that the talent exists to bring this type of technology, or this rediscovery of solid stone construction, to the market.
Q: In your view, what are the biggest challenges to using stone as structure in construction? And how do we overcome them?
A: Mike Picco—I think the biggest challenge is really acceptance by the design and construction community. As Steve mentioned, it was the norm back in the day. Then through the 1920s and 1930s it was left aside and kind of ignored as a building material. So, I think we need to know that it starts first with the architects and designers reflecting back on the successful use of stone as structure in the many examples we have throughout the world. From a technology and industry perspective, as Brian mentioned, maybe quarries and fabricators now have to rethink some of their processing; some of their retooling potentially with some fabrication shops moving toward more cubic material. Material handling might be a little different for some of them. Some may be very easy to adapt; but, I think that’s an