Jochen Thomann and his team build dry stone walls from natural stone. 250 million years old. (Excavator whirring) I'd say he's aging gracefully. After ten or 15 years it still has the same color. The stones are as timeless as the construction methods are ancient. Like a puzzle, like a big puzzle. They build stone upon stone without mortar. Marvin Ude makes the shapeless stones suitable. I like to build a wall with natural stone, with each individual stone, to make it fit, to notice what emerges every day. And you see what you have achieved. (on:) Tight. (Birds chirping) (Machine rattling) (Rumbling) In Oberndorf am Neckar, the landscape gardeners have been putting stone on stone for six months. Stone by stone, they make the Martin family's hanging garden accessible. Around 140 tons of natural stone. Now it's time for the drywall on the house. Without a foundation, no wall can stand, neither stable nor long. So before they place stones, they dig a base. This buffers the natural movement of the ground. This pipe also belongs in the substructure. So that only water collects in it in the future, they cover the drainage in a coat made of fleece. The pipe carries the water out of the foundation and sits at the bottom of the excavation with a slope. Support mats and another fleece complete the substructure. All of this preparatory work serves the stones made of shell limestone, which the Martin family and planner Jochen Thomann chose. Lime and water is a chemical reaction. Mainly from the sedimentary rocks. We have to make sure that they dry quickly after a long rainy season or in winter months when it is humid. If a stone is constantly moist or sits in clay soil and is drained properly, i.e. the drainage drains the water away, it will probably have a short lifespan. It will develop cracks and marl spalling. It will actually dissolve. To prevent it from dissolving, this layer comes in between. A 30 centimeter gravel bed ensures that the water can drain away. For the dry foundation, which is not concrete, we use the gravel mixture. This is a gravel mixture with a grain size of zero to 32 millimeters. There is sand in it, grit, up to 32 millimeters. It can be compacted well. It no longer settles and has distributed the sand among itself. We need a stable material for the foundation. As drainage gravel we use patch gravel or drainage gravel, which is now grain size 16-32. The sand content is completely missing. The only thing is that the water is drained away quickly. The water-conducting gravel will be added to the foundation later. The gravel with sand content is first compacted. Marvin Ude leaves out the area around the drainage pipe. It remains loosely piled up so that the water can drain away unhindered. (Rooming of the machine) Next, another layer of gravel material is added. This is .32 material, but just a loose layer. And we will put the stones into this loose layer. Since the stones are quite uneven on the bottom, we can use the loose material to compensate for these unevenness. That we come out at the top with the top of the stone exactly at the height of the string. (Whirring, clattering) The builders want layered masonry. A stone wall with straight and rectangular joints. Parallel and stepped to the house and slope. We're basically trying to create a negative of the stone through the gravel so that it sits exactly there. The cuboids come from the Würzburg corner. The Franconian shell limestone is considered the most frost-resistant in Germany. The rain and frost of the northern Black Forest don't bother him if he sits in the foundation with drainage. We needed the large stones for structural reasons. There is a height difference of almost 3.5 or four meters that has to be absorbed. The large stones, in terms of their own weight, in terms of statics, would hold the slope. The dry stone wall clearly has the advantages: First of all, in terms of mining, the natural stone is much more ecological than the concrete block, in terms of the CO2 footprint, it has to be said clearly. We preserve niches for small creatures. And the visual aspect is so beautiful. The color of the shell limestone is unique. The beige, the gray, the bluish. We would say that he is aging gracefully. After ten or 15 years it still has the same color. The history of the earth is reflected in the color. Of the soft rocks, they need the large and heavy ones first. There are stones that you grab with the gripper and you notice that they are not suitable because they can break and crumble a bit. We'll see that we can put the stable stones at the bottom. We build with a so-called dosage, or run-up or inclination. This is statically prescribed. You should have a slope of ten to 20 percent. I'm trying to level that out there in the loose gravel material that we threw on top. And put the stone exactly in such a way that it reaches this ten percent. (High excavator hum) My hand signal, because we have difficulty communicating, I show him how to turn the stone. And in which direction he should take him. We are already well established. We now know what we want from each other. If I tell him like that, he should turn the stone around like this. swivel in that direction, that happens over the years. That's where you find your language. Roger Mattes and Marvin Ude found their common language 13 years ago. At first they were trainers and trainees. Today they are construction managers and foremen. That's not so bad. First I'll completely align it the way it should be. (Excavator humming) The 300 kilo colossus should hit the ground running. It is important that the stones always have contact with the others. The stones hold each other in line, forming the so-called butt joint. So they lie stone to stone and therefore do not need any mortar in the joint. He swaps his chisel and muscle strength for a spirit level and a guideline, levels the stone and puts it in the water. Now I used the small spirit level to see whether the stone already had a dosage of ten percent. The stone is 40 centimeters high. Ten percent would be four centimeters, which I would have to put at the bottom and be away at the top towards my front edge of the stone. That's pretty good here. That's fine so far. It's still a little too high on the left side. This can still be knocked down with the excavator. (Distant excavator humming) Dosing in the water and stone on stone are also part of the historical construction method. Fits. Now that was the stone. Building dry stone walls means trying your hand at it. The structure is created stone by stone. You can see it here now. It's pretty flat at the top except for the right side. Very uneven down here, it has so many bumps. This loose gravel material gives me the opportunity to compensate so that it sits absolutely level at the top. Marvin Ude decides whether and when a stone fits well. He places the second shell limestone like the first. Stone to stone, in the water, with dosage. And here at the butt joint, I can see something right away. Before I put it down again later, I can edit a little thing here, knock it away. The overhang is at the stone and at the stone. Then the stone, this butt joint, comes even closer to each other. (Distant excavator humming) This is what the trained landscape gardener does with the so-called fist and setting iron like a stonemason. (Distant excavator hum) Fits. There is another rule in addition to the “stone to stone” rule. Every third stone in a wall should be a binding stone. The front side is now the visible side. Such a binder stone must be twice as long as the depth of the normal row. (Metallic rumbling) All the force of the slope, everything that comes from above, the weight, puts additional pressure on the back. This gives the entire wall this slope, additional stability and pressure backwards, so it can no longer tip forward. Here both or all three joints are now very pressed together. Nevertheless, we still wedge them one behind the other so that our backfilled material, this patched gravel, does not have the opportunity to slip through to the front. The drainage gravel belongs between natural stone and fleece. Here it should drain the water quickly. A floating limestone cracks and dissolves. Colleague Niko Ivkovic is still condensing the shift. (Spring rattling) Everything stands or falls with the first row. The natural stones will later shoulder the main burden. The first day ends with foundation, drainage, dosage, binder stone and butt joints . (Birds chirping) The second begins with the search for the right stones. Like a puzzle, like a big puzzle. When I look at the stones and say, it could fit there. (quietly:) 35. Now for the next one, here is the gap in between, I chose one that can fit well and that can then go in there with little editing. Of course, experience helps a lot. From now on it's brick by brick. Like a 3D puzzle, they should now not only fit vertically, but also sit tightly horizontally on the so-called bed joint. It actually fits me now...not too badly, it's still a bit high on the right side. And if you were to look into the bed joint here, it would still sit a little bit on a point at the back right on the binder stone . You can pluck it away again. I'll knock this corner away, then he'll come down a little bit here and then he'll sit upright. Again with Setzer and Fäustel. (Excavator humming) This is relatively heavy, even the fist. This is a 1.5 kilo mitten. I have more punch behind it, more power. Then it breaks down more for me. That's quite tiring. Over time you get used to it a bit, the gym is no longer necessary. This is what you have during the day. Yes, try to calm down a bit and not put any further strain on your body. Just be a little calmer. The 33-year-old takes it easy when he places the stones. The more precisely they fit, the more stable the drywall will be later. That's why he processes every single cuboid. Without Marvin Ude, nobody sits firmly in the wall. Each stone is a hand-carved unique piece. What is important about the stones is that they sit very well. It rocks very slightly now. But that can now be solved with the wedges. Now I have to choose the right wedge. It has to go in, it can't be too big. So it shouldn't tip over like that. It has to sit between a rock and a hard place. (Distant vehicle hum) (Near excavator hum) Solid. Marvin Ude uses the Motorflex when large parts protrude from the stone and have to be removed - like here. So that the “stone by stone” formula works. The next shell limestone closes the gap between the old and new construction phase. The dry stone wall runs across the corner. To ensure that the loose natural stones are stable in the rows, Marvin Ude places the stones over the butt joints. This is also part of the old construction method. (Excavator humming) Solid. (Rhythmic hammering) Many dry stone walls were built until the 1950s, especially in wine-growing regions. To stabilize slopes and make areas accessible. The land consolidation put an end to the natural stone walls without mortar. Today, dry stone walls are considered intangible cultural heritage in many countries . They are valued again because they provide a habitat for animals and plants. Marvin Ude uses the Motorflex again, this time just scratching the surfaces. This saves him time and energy when he reworks with fists and compositors. His goal: a large-scale bed joint. The arrangement, that the bed joint sits nicely, the butt joints fit together nicely, that's the icing on the cake. This also applies to the Binderstein, even though it is mostly in patched gravel. It carries the slope load and stabilizes the wall. After aligning the binder stone, it wedges the butt joints again and fills the drainage gravel. (Loud excavator humming) (Excavator humming goes away.) It's right in line with me, so I don't have to work on it anymore. This cuboid should go up into the last row, the so-called wall crown. Then the dry stone wall is around 1.5 meters high. It would be really nice from a height. But I don't like the butt joint. She opens up quite a bit at the front, but he has contact at the back. The possibility now would be to saw it off, to split it off. But before that, I'll see if I have another one that might fit better. You have the time factor behind you, you have to pay a little bit of attention when choosing the stone: Which one is the best fit? With which I just have to edit something away so that it sits. Or where I have to say, let's try the next stone. You need an eye to see which stone fits best in which place. With minimal editing, it works. They build walls like bricklayers. They carve stones like a stonemason. They pave paths, plant beds and maintain gardens. With their interdisciplinary tasks, landscape gardeners are not considered a classic trade. They fall into the so-called green professions such as forester, farmer or winemaker. The butt joint fits better. To do this, he needs fists and setters again to create a full bed joint. (Excavator humming) If you want to build a dry stone wall yourself, you don't need a building permit. It may only be necessary to observe the requirements of neighborhood law. If you want to build the wall two meters or higher, you will first need a stability check from a structural engineer. Here in Oberndorf am Neckar there are no legal requirements that would restrict construction. (Excavator humming in the background) Marvin Ude stops the rocking again with wedges between stone and stone. (Knocking) (Excavator hum moves away.) (Excavator hum comes closer.) Sits. (High humming noise) A wall crown is actually placed without binder stones. So, with ashlar masonry there should be at least 15 centimeters of bonding. This has static reasons. So that we get a better offset for the next stones, we can place one along it, which we will split off here later. And now you can continue again with more choice. (Near excavator humming) There will be a lawn here later. And seen this way, the stone protrudes into the lawn. Now I will split it off at the back in line with the other two stones. To do this, I will now drill three holes here and then split them with my wedges. Yes, the holes are now drilled. Now come my riving knifes. (Metallic clinking) They are inserted in the direction in which the stone should break. This means: the direction of the break is this. This means that if we put it in at 90 degrees, this way around, then the impact energy would go around like this. But that doesn't fit. Therefore, in flight. (Footsteps in the gravel) So... And now they take turns tapping on it with their fists. You can tell by feeling when the stone is about to break. Or when a piece is torn. Then the wedges suddenly slide down a little more. Then I hit the other one again, where there is more resistance. And at some point I notice... when it breaks. Zack. (He sighs.) Broken very straight again. (Excavator humming) I really enjoy doing that. Work like this, generally working with natural stone, i.e. natural stone paving, one-liners, work like that, laying paving, that's what I enjoy most. While Marvin Ude is still laying stones at the bottom of the house, the upper part of the newly created garden made of natural stones is accessible and ready for planting. (Distant conversation, hammering) Master gardener Jochen Thomann has a selection of prairie perennials for the beds in Oberndorf am Neckar. Shell limestone and prairie shrubs fit together perfectly. Both are frost-resistant and don't like wet feet. The climate of a region influences the choice of plants and natural stones. This is the stone of our homeland, from the Swabian Alb, the White Jura, the Jura limestone. However, our quarries are now not so suitable for outdoor bricks or slabs. It has to be said that the frost hardiness is too low. There is no resistance to de-icing salt. The Alb-Jura looks good indoors as a window sill, the Franconian Jura as a garden stone. We like to use it as a beautiful stone for Mediterranean gardens, for modern Bauhaus-style architecture, but also for classic, traditional, playful gardens. (Distant excavator hum) The hardest stone that we like to use is also a regional stone, that is the Black Forest granite. It is what granite promises, a hard stone. A stone for the long term, a stone for generations. It's resistant to de-icing salt, so that doesn't bother him either. It is also acid and weather resistant. It is more difficult to work because it is hard rock. We chose the shell limestone because of the style of the house, because of the wooden cladding we have there. And we chose shell limestone as a second reason because you then get a more precise joint pattern. Joint pattern, color play and frost hardness were awarded the contract. At the beginning of the planning, concrete walls were also discussed. (Bird calls) In a case like this, where you have different levels, we would need four or five concrete foundations to make the wall strong. I would even say that this project would be cheaper with all the natural stone than if we had to put in concrete foundations. In the meantime, Marvin Ude has arrived at the hanging wall with the lower wall made of shell limestone. Here he has provided a cornerstone. So, that's about the optics. It always looks very nice when you add it to the corner. The practical benefit is that we can fill the area more evenly. And from the level of the third row along the stone, slope down to the level of the second row. This gives us more space where we can later model the ground for the lawn. The change in the weather does not interfere with placing the capstone. As usual, he puts it stone on stone and stone on stone. Since I like the craft so much, this wall building work, I of course make an effort. I want it to look nice, that I'm happy with it, and ultimately that the customers are happy with it too. I like these adjustments, that it sits nicely, that the result is beautiful. I'm really happy about that too. (Loud excavator humming) That was the last stone. We're almost done with the wall work here. Now I'm going to look up the edges here, look up the escape again. Then we did it. He touches up the edges for the sake of appearance. This applies to the top of the wall as well as to the rows below. It can go up and down a bit in height. But I want to hit the edge itself very precisely. Because that's the row, when you walk towards it, you stand in front of it and look straight ahead. Then it's nice when you see the clean edge. (Clinking hammering) For five days, they used ten tons of shell limestone over a length of twelve meters to build the wall on the house . The final touches for Marvin Ude and his colleagues are to cover the bed joints with gravel and place a barrier layer of fleece on top. (A chainsaw rattles.) Remove support mats and fill with soil. The drywall is finished. (Hammering) The dry-built walls will not need any care from the Martin family in the future. This totally exceeded our expectations, especially when we watched you place the stones so precisely and so precisely. You see a stone like that and think, well, a stone is just misshapen and there's no other way to get it right than to put them on top of each other, but there are huge differences. And we are really happy that it was so successful and also hope that a few lizards and slowworms will feel at home here. That's right. So, I am also very satisfied with the work here. We did it well, we did it well, the stones fit so far. Now you can finish the terrace covering here and then the wall here will come into its own even more. (Distant conversation, metallic rumbling) Although these are stones, as Mrs. Martin also said before, you can't just take them and put them stone on stone, you have to have an eye for them, you have to puzzle something together and also edit, and I have to say that the Marvin has its own high standards, which I don't think can actually be increased. There are colleagues who probably do it as well as we do, but not better. In stone-old construction with timeless natural stone, these dry stone walls will last for generations. (bird calls) Are you as fascinated by craftsmanship as we are? Then subscribe to the channel now and never miss an episode. SWR 2023
