Wil Sillen's post

Wil Sillen

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'Drystack the new 'Lego' 'My invention requires a new profession: dry stacker' By: Jasper Houtman Cement holds the stones together in many Dutch houses. Dennis Deen came up with a more sustainable alternative that resembles Lego. He sold his two companies and put most of the money into this invention. “I had never heard of venture capital.” One day Dennis Deen looked at his two businesses, one for bricklaying and the other for scaffolding, and saw the main bottleneck: cement. His 100 employees were on average 55 years old and new masons did not come forward. Work came to a standstill in frost, because cement may not be processed. “Meanwhile, cement is also responsible for 5% of CO2 emissions worldwide.” Deen included all this in the big question he asked himself: if I don't want to use cement anymore, how do I build with bricks? On that day, five years ago, he picked up a sheet of paper and began to list it. Patent Deen came up with a new way of building with bricks. Holes have been drilled into the stones, a frame of polyamide (nylon) is pressed into it, so that one stone can be 'clicked' on the other. Deen obtained a patent for this invention with his company Drystack. There are now houses according to his building method in Amsterdam, Bergen, Hoorn, Utrecht and The Hague. New projects will follow shortly in Delft and Alkmaar. This year Deen and his company stacked about six hundred thousand bricks, next year he expects to be able to put away three million. He is now noticing enthusiasm abroad. 'Girls like it because it doesn't make you dirty, like bricklaying' In retrospect, it seems like an easy step from the wish list on paper — for example, the method had to be easy to learn and perform in all weather conditions — to the jobs that Deen is now allowed to do. “But before you get here,” he says with a sigh. "It was all or nothing. At home I often said it would take a while. My wife would then respond with: “You could have just gone into real estate”.' Self-designed machine Deen started with a machine of his own design that could drill sixteen holes in the stone. That process had to be refined to the nearest tenth of a millimeter. The current production location in Velsen-Noord contains the latest versions of the machine. They are equipped with diamond drills that hardly wear out. Usually the stones still have a cement joint after stacking. “That's just for the sake of sight. In houses it is watertight and airtight inside. The brick is only there for finishing.' It is therefore still the cheapest, most maintenance-friendly and most durable product, according to Deen. "I don't think the brick will disappear for that reason." The novelty of a stacked brick facade raised eyebrows and also curiosity in the market. ‘A specialist in bricks and roof tiles in Delft was immediately enthusiastic and that resulted in orders. Then we left.' Interest among architects was sparked by rules for circular construction, in other words the reuse of building materials. Roughly speaking, 'dry stacking' costs the same as building with cement, says Deen. Millions Deen invested millions in the development of Drystack, which now has fifteen employees. “I had never heard of venture capital. I went to the bank, but they asked for the figures for the last five years and you don't have that as a starter.' Last year, the entrepreneur received help from investors, who also took on a managerial role. They recently raised capital from six industry financiers, including construction company Dura Vermeer and project developer Flow Real Estate, but Deen would not name an amount. “We need thirty machines and an organization for that expansion. Then you talk about millions.' On the paper from years ago, Deen also referred to training quickly. ‘We have to establish a completely new profession in the Netherlands: dry stacker. VMBO schools think it's fantastic. Girls like it because it doesn't get you dirty, like bricklaying. Sustainability certainly plays a role in the interest. Moreover: you leave after a day's work and there is something there.' https://youtu.be/N1oxAuW62g0

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