The numerous creative street mosaics play a major role in Freiburg’s unique charm. On a walking tour, you’ll walk over colorful Rhine pebbles, dark basalt, and even white Carrara marble. One person who is very familiar with the intricate art of mosaic paving is master paver Dieter Saier. In this interview with STEIN, he talks about his varied work.
STEIN: Mr. Saier, Freiburg is known for its paving mosaics. How did this craft come to the Breisgau region?
Dieter Saier: It’s still unknown todaywho first invented this type of paving. It is said to have been the Freiburg paver Alois Krems who, during his travels through southern France around 1870, discovered the technique of paving with split pebbles and used it here in Freiburg to create Rhine pebble mosaics. In addition, split Rhine pebbles were used to cover the entire surface of sidewalks because their flat surface has proven to be very comfortable to walk on to this day.
What exactly are mosaics?
Mosaics are generally nothing more than symbols for artisans or cities. When we speak of coats of arms, these are images that must be depicted strictly according to certain heraldic rules.
What stones do you use for the mosaics?
Rhine pebbles, a specialty of the Upper Rhine region. In addition, small-format mosaic stones made of basalt, granite, or marble are used. The Rhine pebbles are oval in shape and have a lovely convex top. They originate from the Swiss Pre-Alps, which the Rhine has carried through Lake Constance to the banks of the Rhine in our region. Their characteristic flat elliptical shape and intense colors are the result of being smoothed by the water. Because of their varying mineral content—and thus their multicolored appearance—they are incredibly well-suited for creating mosaics. As a special treat, there’s also Carrara marble. It’s even often used to mark crosswalks.
That must cost quite a bit, right?
I sometimes wonder about that too. But it’s worth investing in quality, because we can reuse the STEINS multiple times. For example, if we have to dig up a traffic area, we can often reuse a good portion of the STEINS. That wouldn’t really be the case with other materials. In that sense, the investment makes sense. The Old Town was completely devastated after the war. There, too, we were able to reuse many building materials. Even today, we have carefully preserved treasures at the building yard that we use in our designs, such as Rhine pebbles, basalt, porphyry, granite, and marble.
Has anything changed recently?
We’re creating more and more accessible public spaces. And we do so with mixed feelings. Because in some cases, we have to cut off narrow strips of the historic convex STEINS. The new, very flat surface naturally looks quite different to the eye at first. It no longer seems as lively. But we do not neglect historic preservation.
What does that mean in practice?
The shape, the mineral composition—whether laid in rows or arches—all of that is preserved. We’re only changing the surface, thereby striking a balance between functionality and design.
What method is used to lay mosaics?
In the past, the unbound method was preferred for aesthetic reasons. In this method, loose mosaic stones were laid directly on the street in a bed of sand, and the joints were also filled with sand. Moss would then grow in the joints, which blended beautifully into the landscape. If the stones were very small—about the size of a thumbnail—the roughly 1,000 stones per mosaic were laid in cement mortar.
So does the surface of the joints play an important role in mosaics?
It’s crucial. For one thing, they make up a large proportion of the mosaic; for another, the joints form the actual lines and textures. A mosaic laid in mortar has more exposed joint surfaces compared to one laid on a sand bed. They remain gray, so to speak. We still use the unbound method today, but less frequently—for small, less expensive mosaics. In these cases, we’re talking about one or two days’ worth of work.
Doesn’t the sand get washed out quickly due to the weather, or do the STEINS come loose from foot traffic?
We only have problems where rain drips from the awnings. Otherwise, the rain consolidates the joints. And after two years, they’ve become encrusted with microorganisms and moss. But the city’s street sweepers are a problem because they suck the sand right out of the joints. That’s why the city is only allowed to sweep these mosaics by hand. If the sweepers didn’t exist, we could use the unbound construction method much more often, as we’d like. Because it’s more visually appealing, more environmentally friendly, and significantly cheaper. But of course, we’re also aware of the traffic demands placed on these areas. So we have a conflict of objectives here.
Are pavers commonly used today?
That’s right; the current method of laying mosaics in tiles has gradually become the norm. Because, as already mentioned, sidewalks and streets have to be dug up more and more often to access utility lines or similar infrastructure. In these cases, we can, of course, remove the pavers without damage and reinstall them later. For this purpose, the pavers have handles that are hidden in the ground. For example, the last partner coat of arms cost 12,000 euros.
Are so-called stencils also used here?
Yes, the templates are like a puzzle made of wood or plastic. For example, if you have a finial with four petals, the template consists of four pieces. First, you place all the puzzle pieces flush against the bedding. Little by little, you remove a puzzle piece and fill the area with STEINS. Finally, you pave the background.
A look into the future: Will your profession as a paver still exist?
Absolutely. Training centers are seeing an increase in enrollment. There’s a real effort to attract new talent. Because as housing needs grow, we’ll have to develop more and more new areas. And that means maintenance work will also increase. The profession isn’t academically oriented. But you can—let me put it this way—advance your career significantly with a standard level of education, becoming a technician, an engineer, and so on. What you need—whether you’re male or female—is skill, dedication, and creativity.
In the latest issue of STEIN magazine, No. 08/2018, published today, you can read more about the major construction project to pave the Freiburg city center ring road with granite and basalt, following the renovation of the city’s historic district. Our STEIN contributor Tanja Slasten describes what it means to be “committed to history” and how the redesign is being implemented.
