Tony Sheridan on Building a Greener Future with the Revolutionary Cemfree Cement

[00:00:00] Speaker A: Constructive voices, the podcast for the construction people with news, views and expert interviews. [00:00:07] Speaker B: Hello and welcome to constructive voices. I'm Steve Randall. Concrete is everywhere and that's unlikely to change anytime soon. But environmental concerns about its key component, cement, is driving change within the industry, with alternatives offering a far lower carbon footprint. Jack Deburker has been finding out more about one of the emerging solutions. [00:00:29] Speaker C: I'm Tony Sheridan. I'm the commercial director at DB Group, which is the parent company of Semfree. I've been working here for about five years now. Originally I trained as a structural engineer at UCD in Dublin and worked as an engineer in Dublin for nearly ten years and then did an MBA over there and then came over to London. And I've been in London for just over eleven ish years now. Time flies. And in London I worked in the building material sector, used the MBA and the engineering to get into the building material sector. Worked for a company called Hansen Heidelberg Materials, now one of the majors in the cement and concrete space over here. And I worked in their major projects team for a few years and worked in some line management roles, general manager and commercial manager roles, and in total worked there for about seven years and then heard about Semfree and DB Group jumped as a chance to work here about five years ago. And really the reason for that was the idea that Semfree being such an amazing opportunity and material opportunity for concrete and for cement and for construction to decarbonize. Just that the thought of being able to decarbonize all the concrete I've been specifying or producing or supplying for the last 1520 years was a huge thing for me to be able to try and get involved with. So I came here and have been working here ever since. [00:01:42] Speaker A: Fantastic. So let's backtrack a little bit to before you arrived in Semfree, Tony, how was the product actually born? [00:01:51] Speaker C: Yeah, so Semfree is the brainchild of a guy called David Ball who is the DB of DB group. And he about ten years ago came up with this idea to use alkali activation to activate ggbs, which is a waste material in the construction industry, and to make essentially a binder, a powder binder which could be used instead of cement to make concrete. And so that idea kind of got born about a decade ago. David then brought it into the DB group company and we've used one of the other companies in DB group. Puddle, which is a very successful waterproofing company, has essentially been the source of funds and expertise to grow Semfre from what it was as an idea into something that was actually saleable and ready for market. And then the past five years really going to market and making it sort of at industrial scale and delivering carbon productions at a real noticeable level. [00:02:51] Speaker A: Why, Tony, do you feel there is a need for alternative products like semfree? What's the problem with concrete cement? [00:02:58] Speaker C: It's a huge issue really. Concrete is amazing. Concrete is an incredible material. It's durable, it's versatile, it's strong and it's an amazing material to build with. And as an engineer, I can tell you, engineers love concrete. Current projections are that most society will be living in urban environments by 2050. I think 70% of the world's population will be living in urban environments in 2050. So that means a lot of concrete, more and more concrete every year. The problem with that is every ton of cement that's produced produces nearly a ton of co2 into the atmosphere. That's a big problem. In the UK the number is a bit better, it's about 850 kgs per ton, but it's still a big number and a big problem. So you got this concrete, which is great and being used more and more every year and you got to this cement in it which is a big problem and it's needed in it because it's what makes concrete go hard and get strong. The cement industry is responsible for 8% of global co2 emissions every year. So if it was a country, it'd be the third largest emitter in the world. So it is a big global problem. And we can't just stop using concrete because then we won't have any roads or bridges or hospitals or schools or houses to live in. So you need concrete, but we need to find a way of having concrete without cement. [00:04:05] Speaker A: Those are some very impressive stats, Tony, for the wrong reasons. Obviously the government, obviously we're talking about the UK now, has set net zero targets for the construction industry. What does this mean for the industry, Tony, and how can they hit those targets? [00:04:23] Speaker C: That's a big and complex question really. The government has set targets, legally binding targets for 2000 and 32,050, but hasn't really set the roadmap for construction to follow to hit those targets. It's kind of left industries to their own devices to see what they can do themselves, which in some ways is good because it leaves expertise where it probably is best placed, which is in the industry. But the problem is that that leaves everybody in the industry to go off and do their own thing. So you're left with a fairly dispersed set of ideas and a fairly dispersed set of activities that can feel a little bit disjointed. Every sector of infrastructure or private sector, almost every company is doing things their own way. That lack of clarity and joined upness, if you will, is a problem. And the government could be doing more to help with that. If you look at, say, the states where you got the Inflation Reduction Act, I think that's being widely hailed as something that's really positive and proactive in terms of delivering sustainability goals because it is a bit more of a roadmap and a bit more structured. We could do something like that here. That said, a lot of really good stuff is happening in the construction industry to try and get to net zero. Huge things are happening which are very exciting and there is a lot of drive to try and join it up a lot more, but it's kind of from the ground up and it's not being led by government. [00:05:45] Speaker A: So yeah, you've touched on that, obviously, Tony, what is currently be done in the concrete industry that you're aware of to help reduce the carbon impact? [00:05:53] Speaker C: So if you take that kind of bottom up approach, a lot of infrastructure clients, for example, who are probably most focused on the government targets because a lot of their funding is directly from government, are really driving hard to reduce carbon in everything. And being infrastructure clients, they tend to use a lot of concrete. A lot of concrete goes into infrastructure. And so they are focusing on it in their own ways to try and reduce carbon. And some who are more advanced than others are starting to actually put products like SEM free as a carbon reducing replacement to cement into their specifications, and driving towards using SEM free or products like Semfree in a kind of a business as usual case, as opposed to doing demonstrations or one off supply. So we're moving the needle forwards a bit, moving the dial towards a kind of a business as usual state to really drive carbon out. So they're doing the work themselves to understand the materials, to get the designers on board, get the supply chain on board, to be able to take carbon out by taking cement out, which is huge. That's kind of sort of sector by sector, client by client, industry wide. We're actually directly involved in a group called the low carbon concrete group, which is a very powerful movement, I think really in terms of what it's trying to achieve. It's set up by the UK Green Construction Board and by the ice, the Institute of Civil Engineers. The idea is basically to run a whole bunch of parallel programs, work streams, taking a wide group a diverse group of stakeholders and selecting them to run a whole parallel list of work programs to try and decarbonize concrete, specifically including the name the low carbon concrete group. I guess the work streams are very wide reaching. They're everything from how do we reuse buildings more than we do now? How do we use supplementary materials and recycled materials more than we do now to take the high carbon bits of concrete out? How do we design more efficiently so we don't over design where we don't need to? How do we use alternative materials that are not yet in standards, such as products like Semfree, to take out cement entirely? And so there's lots and lots of parallel work streams, and lots and lots of engagement across industry, across different stakeholder groups to try and make sure that those work streams are as effective as possible. One we're directly involved with is actually specifically around british standards and adoption, and allowing easier adoption, faster uptake of products like Semfree to replace cement entirely and dramatically reduce carbon in concrete in that instance. So we're doing things like, there's a thing called a flex 350 standard that has just been written and is now at Republic consultation at the moment. And the low carbon concrete group were the people who were sort of instrumental in getting it written. That has been written by the british standards, the BSI, and it's a mini standard which will allow performance based specification. It won't matter whether it's cement or a different kind of binder that's being used to make concrete, which is very helpful for designers, because then they can select things that aren't cement to make concrete and therefore reduce carbon. And that's kind of a really big step forwards in terms of the concrete industry and its ability to use novel materials. So there's a lot of things going on, a lot of parallel tracking of trying to get carbon reduction initiatives of us moving and trying to get them as widely adopted as possible. It's very exciting. [00:09:18] Speaker A: It sounds really fascinating. It's probably, by the sound of the complexity and the parallels that are running there, it sounds like another podcast in itself, which possibly something we could talk about. But going back to Semfree, Tony, how much embodied co2 can it save? [00:09:35] Speaker C: So we believe we're actually market leaders in terms of the amount of carbon we can take out of concrete and concrete products. Certainly the stats we've seen across the industry would suggest that if you take our Optima product, we've got a number of products. Now, if you take our original product, Semfree Optima, which is a powder can come in a silo or it can come in a ton bag or come in a 25 kg bag, just like you'd see with normal cements. The carbon footprint per ton of optima is 133 kgs per ton. As I said earlier, the carbon footprint of ton of cement in the UK, the industry wide stated that is about 850 kgs. So you're talking about kind of an 85% reduction in embodied on a ton for ton comparison. It's significant. It's a large chunk of carbon can be taken out very quickly if you just take out the cement and put in SEM free. I would say that there are others available. If this was the BBC, there'd be others. The line. Other cement replacements are available. There are, and a lot of them are very good. We just know we happen to be the best. Okay, so that's taking the powder as a direct comparison. Nobody actually builds using the powder they build using concrete, don't they? So nobody really cares about the powder, they care about the concrete or the product that's made with it. So if you talk about, say, our masonry mortar, for example, where we have used sempre optima and we have made our own masonry mortar with that, and that's a product that's available now. It's been available for nearly a year, and it comes in bags and it's just like normal masonry mortar. You put it in between blocks and you make walls. Very simple stuff. When you add up all the other carbon that's involved in putting a bag of masonry mortar together, the cost, the carbon cost of the packaging, the deliveries, the carbon cost of the sand and the other additives in a bag of mortar. We're using the same sand as a cement based mortar and the same packaging as a cement based mortar. The carbon savings from having SEM free in there instead of cement, when you look at a bag of the mortar, is 70%. So you can save 70% of your embodied carbon in a wall by using SEM free mortar instead of cement based mortar. And actually, in the same way, by using a SEM free block instead of using a cement block. So if you're a designer or a developer or a client, and you've got a block wall to build, or a house to build, or a building with lots of blocks in it to build, and you want an easy way, you're reducing your carbon where you don't have to worry about design implications, you don't have to worry about retraining all your site staff to do a different thing, a different process on site, simply just switch out one for the other. You can achieve a 70% reduction in that wall or that building or that part of the building by going SEM free instead of OPC based. [00:12:17] Speaker A: That sounds like a very easy fix that you're offering there. What other solutions and technologies are available in the market now? Tony? [00:12:24] Speaker C: There's a huge variety, really, in terms of what is out there and what can be done. As an advocate for SEM free, I'm an advocate for the whole gamut. I think we should all be using all this stuff, not just Semfree, but anybody else who's trying to reduce carbon. We see ourselves as part of a very patchwork solution, a very wide range of solutions that will solve the carbon issue. In concrete. There's not a one size fits all approach here. So there's lots of different things that are being done. So, for example, people are injecting carbon into concrete so that there's companies out there who can inject carbon into concrete. And in doing so, they reckon there's a 15% ish reduction there. There are people who are doing things like cast iron clay, which is a very exciting development in the concrete industry, which is a good step forwards from cement. It's still a linear process. You're still digging something out of the ground and burning it at a high temperature, and there's still a fair chunk of carbon involved in all that. But it's a notably different notable reduction versus OPC cement. There are other things like doing more blending of different waste streams and different materials to basically replace some of the cement in concrete mixes. So turnary blends is what they're called. So putting three things into a blend as opposed to two, which is what's done normally now, but there's also things like carbon capture as well, which is a future development, which could be a huge part of the solution if it gets developed properly and is able to be used properly by the cement industry. And then there's things like us, which are. We're part of a group of products called alkali activated cementitious materials, aacms or geopolymers, some people refer to us as. And there's a number of us in the market at different stages of development. To be fair, some of our kind of our competitors that I suppose are an earlier stage in their development than we are. Some others are roughly where we are in terms of having good experience in the market and having something that's been used fairly widely. And yeah, I think where I see it is, it's a bit like a parallel to the power generation industry in the UK, where you used to have one way of doing things very centralized. You used to have the UK wide power company which burned coal to deliver electricity to everybody's home, and a very centralized approach with one way of doing it. And now if you look at power generation in the UK, it's very dispersed, it's very multifaceted, and you have people even selling power back to the grid themselves. And you can see a similar path for cement, where currently it's an oligopoly. It's run by a handful of companies, I think five or six in the UK, across nine cement plants, making cement. So doing one thing and selling it out nationally, whereas I think in future we can see a very wide, diverse way of making binders for concrete as opposed to cement. [00:15:16] Speaker A: That's a great comparison, Tony, to the power situation, obviously in the UK. Very good comparison indeed. Now, going back to the various technologies that you've just described, how do you feel the industry is adapting to them? [00:15:29] Speaker C: At the moment, it's a mixed picture. There are a lot of pioneering companies that we've had the pleasure of working with, and I'm sure some of our competitors have as well, who are really trying to drive forwards as fast as possible. And there are some others who are just a bit more cautious about moving forwards or cautious about doing something new because they see risk as opposed to opportunity, which is understandable. But I'd say that if you were to take a broad brush, I'd say that a lot of companies, again, if we go back to infrastructure clients, for example, who are more directly affected by or directly interested in the government targets, given being that they're usually government funded, are really driving hard to try and reduce their carbon and looking for solutions and therefore working harder to try and do things like use Semfri or other AACMs in their concrete. I've been doing this for five years now and I've seen kind of a step change. In terms of five years ago, we might have been knocking on a lot of doors and getting some slightly indifferent answers to the last couple of years where the desire for this change in the carbon content of concrete and the carbon content of construction is really ramping up. And now people are knocking on our door saying, what can you do for us? Please, we need help. And people are in infrastructure are saying, we need to do this as business as usual as quickly as possible. How can you help us do that? Or how do we do that? Can you help us on that journey? It's rapidly gaining a lot of traction. So it's an interesting time, I think there are complications and there are roadblocks, and we're trying to overcome them. The standards thing I mentioned about Flex 350, that's us trying to overcome a roadblock, which is the british standards for structural concrete, where they are prescriptive, and therefore it's harder to design without cement, that prescribe an amount of cement in concrete to be in the standard. And that's harder to get around, but you can work through it. And as I said, some of these more enlightened companies or innovative companies are finding ways of working around that and have found very successful ways of working around that by designing by first principles and getting comfortable with the material and doing the testing to allow them to then specify it in their specifications in an ongoing way. [00:17:39] Speaker A: One of the things that occurs to me, Tony, with the product itself, the product range itself, is there quite a lot of R D still going on at Semfree? How does that side of things work? [00:17:52] Speaker C: Our business really is primarily selling the binder, selling the cement replacement, and we are doing a lot of work and have been doing a lot of work with a lot of companies who make concrete products and developing their products to be able to be SEM free versions of their products. So block manufacturers, brick manufacturers, precast paving manufacturers, mortar manufacturers, bulk mortar manufacturers, all these kind of very large companies, actually, in some instances, very keen to be able to supply the cement free version of what they do. But there's a journey there in terms of developing the SEM free version of that and doing all the testing on those products to make sure they're fit for purpose, and then launching the product into the market. And in some instances, that's a multi year development program. A lot of our work in the technology team is in supporting that product development work. So the D and the R and D, I suppose. And that's really exciting, actually, because going back to that block wall example, if you've got a block now from a block manufacturer, which is SEM free and has a circuit 70% carbon reduction, you've got a mortar from either us or from a bulk mortar supplier which has a similar carbon reduction, all of a sudden you've got very simple ways of just changing, just changing out one standard block with another standard block, but you've taken 70% of your carbon out of your wall. So it's quite powerful, actually. A lot of these products have performance based standards already, so they are actually easier to adopt widely. They haven't got that barrier that structural concrete has with the british standards and the reason for the flex 350 in that instance. So there's a huge opportunity for designers and clients and house builders, for example, in the block instance, to make big switches and big carbon savings immediately now, without having to worry about changing designs, changing ways of working, changing manufacturing processes. It's all there ready now. So that's the development stuff in terms of the research stuff. A lot ongoing in that as well, actually, we've originally had one product which was a powder, we call it optima. And more recently we developed two new products which have slightly different characteristics. Faster strength gain, higher strength gain, that kind of stuff. One's a liquid and one's a powder. And that's come directly from the research we've been doing over the past couple of years, few years. And that research is ongoing into new versions of our products which have better strength characteristics, again, perhaps better setting times better, some different characteristics for different niches in the market as we see them, as we develop relationships with different manufacturers. But also what we're really pushing into is developing ways of activating different waste streams as well, and really opening up into lots and lots of other potential pure wastes from lots of different industries that can be activated using different chemicals and become different versions of SEM free binder. And that's the future, really, of the industry, I think, is being able to take wastes from multiple sources to understand the chemical compositions and the mechanical compositions of those materials, and to have the ability and the wherewithal to be able to activate them, to make cement replacements. And that brings us to kind of taking materials from all around the world, depending on where the contractor, the construction is happening, and activating local materials with local chemicals and delivering really ultra low carbon binders for local environments. [00:21:25] Speaker A: That's super exciting, obviously. [00:21:27] Speaker C: Yeah. [00:21:28] Speaker A: Now, Semfree obviously has been used by, I hope I'm going to pronounce his name correctly, Arsleff, in the world's first trial driving cement free, ultra low carbon precast piles. Now, how has that gone so far? [00:21:45] Speaker C: Tony, we've done a lot of work in piling in general at Semfree over the years. Not in precast piles, but in other kinds of piles. So just in more widely used piles, in female piles, bearing piles. We've been in permanent structures and in temporary structures for dozens of projects, really, and some really high profile ones too. We did some piling for hs two and stuff, and they were female piles. We've done a lot of piling and understand some of the aspects of the piling. Well, we understand the piling market, really, I suppose, quite well. The reason why we were doing this project was we were doing an innovate UK funded, grant funded project to demonstrate how good SEM free is in aggressive grounds, aggressive environments, because we had seen from our piling work and our research in our lab that SEM free concretes are better in aggressive ground than cement based concretes. And that could be another advantage in using something like SEM free instead of using cement. We took on this project with innovate UK and other partners to demonstrate that and take data to prove it in a very clear way. So we used one of our newer versions of Semfree, Semfree Rapid, which had a faster and higher strength gain than our original Semfree. And we used that to make some precast piles with RSLAV and to drive them into the ground, and then take data from those piles in the ground to confirm what we already know, which is that the Semfree piles perform better in those aggressive environments, in those aggressive soils. So the piles were driven, were produced and driven in 2022. And that was great, because we were able to show that a precast manufacturer, who usually want very, very fast curing times and very fast turnaround times for their molds to be efficient in their factories, they could use something like SEM free instead of cement, and still have all the same operational metrics that they would have normally, and no need to disrupt what they do in their normal practices. And then they made the piles, and then they could also take the piles to site and they could drive them. And that basically means sticking the big column up in the air and whacking it with a massive hammer and driving it into the ground, which is a fairly disruptive thing to do with a concrete structure. Lo and behold, the SEM free concrete performed just as well as an OPC based concrete, a cement based concrete, in that you could drive it into the ground with no problems. So really great on that regard that we, without having redone it before, did it with our Semfree rapid, and it worked really well. The data we have to date on the durability aspect of it are proving what we know already, in that the early data is showing that the Semfree piles perform better than OPC based piles. That data is going to be gathered for the next five years, I think. Well, four years now, I guess, to get a longitudinal study going in terms of showing that over five years, you'll see the same kind of results as you have seen already. So, yeah, really excited, actually. It's really good. [00:24:50] Speaker A: That is very exciting now. So, yeah, I was just going to ask you about durability, obviously, because it's alkali activated, but the studies are ongoing, the initial results are positive. And that's basically what you're saying, Tony. [00:25:03] Speaker C: Absolutely, yeah. We have a lot of data already and we've got a lot of lab data and a lot of data of having SEmfree in use for the past number of years, particularly with our original product, which shows that Semfre outperforms cement based concrete in a number of environments. That's not that surprising. If you look at how Semfree is made, if you look at the chemistry of it, it makes a lot of sense. So the desk based study would tell you that's the case, our lab based stuff tells you that's the case, and then we look at it in real life applications proving that it's the case. And we've got data dating back for nearly a decade when we were doing initial trial work and initial mixes, line work to show that. Yeah. And so things like, for example, if you take in agriculture or even in sort of wastewater treatment, I suppose, where you've got acidic sort of acids, weak acids acting against, say, slab in a yard on a farm where it's slurry or it's something like that that's acting on the concrete. If you use a normal cement based concrete, what you tend to find in the industry is that the concrete gets overdesigned. You end up seeing designs for like a 50 Newton concrete on a yard, which doesn't need to be anything like that for structural reasons. What they're doing there is they're putting in more cement because they know the cement is not going to react very well with the acids that are being exposed to, and it will deteriorate quite quickly. So by beefing it up, they make it last longer. Well, actually, with SEM free, you don't need to do that. The material itself inherently performs a lot better versus those kinds of acids and those aggressive environments, and therefore, you don't need to over design it in the first place. You can design it for what it structurally needs to do, which is actually quite weak, but it will maintain itself over time in terms of how it interacts with those acids. So you can actually design more efficiently in these cases by using SEM free or an AACM instead of using OTC. So a, you get the benefit of not having the carbon in there, and b, you get the benefit of not having to over design in the first place. [00:27:09] Speaker A: Fantastic. So I have a headline here that I picked out during my research. Cement free concrete puts network rail on track for carbon savings. This was published in the Institute of Civil Engineers. Tony, can you elaborate on this? [00:27:26] Speaker C: So again, network rail being one of these infrastructure clients who clearly have got their eyes on carbon and carbon and concrete. They're not the only ones. A lot of infrastructure clients are really focused on it, but this is a really good example. Bam Nuttle were the construction company, and we were talking to Bam Nuttle about this because Bamnuttle wants to show the clients, Network rail, that they could do this. And we worked with them on getting a mix design, and we worked with them on proving to Network rail and themselves that SEM free was fit for the application. So everybody was happy that it could work. And then we went and supplied, and it was a 300 meters tube to concrete and one continuous pour over about 10 hours. Wow. And it all went really well. Everyone was very happy afterwards. So it was a low grade application. It wasn't a particularly strong concrete that was being needed. In fact, it was just filling a void, I think, really. But it was necessary for the void to be filled. So because it was a low grade concrete, it was a low cement content, a low binder content. I think we saved about 60 tons of carbon on that one project. I mean, 300 meters cubed in one pour is a good big single pour, but in terms of the scale of the concrete industry, it's a drop in the ocean. But we still managed to say 60 tons. What strikes me about it, what struck me about it was if they hadn't used SEM free for that 300 meters, they would have used cement for that 300 meters. And it just speaks to back to how addicted everybody is to concrete and how great concrete is and how easy to use it is, which is great, but it's a problem because it's got cement in it, and there's thousands and thousands and thousands and thousands of meters cubed of concrete being poured in low grade applications up and down the country with really zero risk of catastrophic failure anywhere. I mean, mass fill isn't going to cause a problem if it crumbles a bit. Not that SEM free would crumble, but you don't have to build a 50 story tower with SEM free to save tons and tons and tons and tons of carbon. You can put SEM free now, even though it's not in the official standards, you can put SEM free concrete into all sorts of weird and wonderful low grade applications now and save thousands of tons of carbon in doing so. That's just a huge opportunity that is, I think, rapidly being recognized, but has been missed. [00:29:47] Speaker A: Interesting, very interesting. So I would be rude not to ask. I'm sure listeners would think, well, why hasn't she touched on the financial aspect? How does it compare in terms of budgeting for whatever examples of projects that you've worked with, infrastructure or otherwise, how does it compare to the traditional. [00:30:07] Speaker C: There's a couple of things in parallel really, on that. One is I think concrete is actually underpriced in the market. And I think if concrete, cement and therefore concrete were priced for value, you'd probably see a different price point at the start of all these conversations. That's a slightly secondary thing, I suppose. Cement currently in the UK market is priced at, depending on where you're buying, at 120 to 150 pounds a ton. The price has moved quite a bit in the last couple of years, so it does change rapidly. It was very static for a long time, but since COVID it did move quite a bit in Brexit, it did move quite a bit up north. I think it's stabilized now a little bit. That's the cost of cement, not accounting for the cost of the carbon in the cement. And so if you were to apply the logic of carbon credits or carbon trading to that, you would add probably 50 to 80 pounds a ton to that. And similarly, if you're talking about carbon capture and ccus, that's probably got a 40 to 50 pounds a ton price tag on it. So depending on how you want to talk about the price of cement, it does change a little bit in terms of how you want to recognize those kinds of issues. SEM free is more expensive than cement in its current price. So the powder on a light flight basis is more expensive than cement. Usually you would see, well, it depends on how we deliver it. You can get down to about, I'd say, 60% more expensive than cement on a ton for ton basis. And in some instances, depending on how it's being delivered, it might be 100% more expensive than cement on a light for light basis. So if you take that price point and talk about what that means for a product being made with the cement, or therefore a building being made with the products that are being made from that cement, you take the increase in cost downstream, if you will. You see that by the time you get to, say, the house that you're building with cement blocks and bricks, for example, you're barely having an impact on the cost of the house being built. You're almost in rounding errors for the cost of the house being built. The cost of the bricks and the blocks could be anywhere from 8% more expensive using SEM free versus cement, to, say, 30% more expensive from using SEM free to cement, depending on, again, how it's delivered and how expensive the block is in the first place, what kind of block it is. For example, there are cost uplifts and the powder is like. Is more expensive. By the time you put it into concrete or a concrete product or a brick or a block or mortar, that price uplift gets washed out quite a lot, quite a bit. So you're in the kind of the ten to 15% price uplift in general. And then by the time you take that block, brick or precast element and you put it into a house or a structure, the additional cost for that element within the structural cost is in rounding errors in terms of what the cost of the building was. So it depends on really how you want to frame the question. But my answer to that would be, it's more expensive, but really, for the carbon you're saving, it's worth every penny. [00:32:57] Speaker A: Sure. And I think we're now at such a crucial stage that I suppose we'll mention Network rail again. What a great example that we spoke about previously. Lots of entities, as you say, people that you've been dealing with, companies that you've been dealing with, that they have the foresight to understand that their brand is really important, that what's happening with the planet obviously is massively important. So for how you've calculated it, for like a small difference at the end of the whole process, that's not meaningful. During this time, I would say five. [00:33:32] Speaker C: Years ago, that was a real sore point in conversations. People wouldn't be able to accept that logic. But over the past few years, we've seen a huge swing and people now recognize that it's worth it, that the cost uplift is actually very manageable and that it's worth doing for lots of reasons of brand and that kind of thing, but also just the ethics of it, the fundamental need to take carbon out. We have to do it. I mean, you can save 20 p if you want, but you're heading towards an iceberg on the Titanic and you want to try and change course, don't you? [00:34:08] Speaker A: Very much so, yeah, very much so. Great comparison. What kind of plans and targets does Sempre have over the next ten to 20 years? [00:34:17] Speaker C: Big ones, I would say big ones. Very exciting ones. We're still a very small. So DB Group itself isn't a huge company, but Semfree is small within it. Still, we've got about, I'd say across the piece, about dozen people working directly for Semfree in terms of commercial and technology, and we've got big plans and big ideas to try and grow as fast as possible. We've been doing a lot of work in terms of onboarding some very big customers to get those products to market more easily, available, more widespread, to help clients make the switch more easily. And we're trundling along with that work. And I think we're seeing a step change now in the availability of these products and therefore the growth trajectory of the company. So that allows us to grow in terms of commercial effort and also in terms of technology and r and D to expand on the research bit in particular and the R D as well, and develop even more of those alternate precursors I mentioned earlier. And also the plan is to go so big growth in the UK, but also big growth internationally. We've been looking at other markets where the cement usage is high, where the green agenda is front of mind with government and with construction, and where we can see that the frameworks for the legal frameworks, I suppose, and the kind of the standards frameworks are suitable for alternates like Sempre to be used reasonably widely. And so growth in the UK will help fund a lot of that international expansion that we've got on the books as well. So yeah, big, big plans, very exciting time, actually. And it does feel like we've done a lot of really great work under the radar here in the UK for a number of years, and we're about to really go big. Go large. [00:36:03] Speaker B: That's Tony Sheridan from Semfree talking to Jackie de Burker. And that's all for this episode of Constructive Voices. Please take a moment to share it with others who may find it interesting. 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