During the Devonian era 400 million years ago, slate was formed from clay layers deposited in the marine alluvium when mountain ranges folded. Lateral pressure during the folding process gave the clay masses the fissile properties of modern-day slate. It is only with the correct chemical and mineralogical composition that the slate acquires the colourfastness and weather resistance that is so important to the consumer.

An important factor is the reliability and long-term experience of the slate dealer. Theis-Böger offers its customers an above-average guarantee.

Good slate is highly resistant against the aggressive effects of the atmosphere and chemicals of all kinds. It only undergoes a natural weathering process during its service life of approximately 80 to 120 years. Our slate is resistant against flying sparks (fire category A1) and frost.

Assulo® and Altlayer® slate have the well-known anthracite-grey colour. A unique gloss effect occurs when the sun shines on it, something that can only be found in natural products. Monte Color® slate is available in natural colours, i.e. reed green, emerald green, bordeaux red and multicolour.

Three reasons why you should use slate

• Economically viable

Depending on where it is mined, a good slate tile will last between 80 and 120 years, with low maintenance costs. Subsequent generations will not be confronted with high disposal costs, as slate is a completely natural product without pollutants. Our new easy-tiling methods mean that your initial investment comes very close to the cost of a similar, artificial product.

 

• Visually incomparable

The colour and gloss of TB-slate makes a pleasant contrast to imitations and other alternatives. Monte Color® slate comes in a wide range of natural colours which, either on its own or in combination with Assulo® or Altlayer® slate, makes for a pleasing colour effect, which is a joy to behold.

 

• Good ecological profile

> Low-energy mining

With the exception of the production of raw slate slabs, slate production is still very much a manual business. In contrast with other roofing materials, no artificial heat treatment is required. Slate roof tiles are only mechanically processed during production. The average energy consumption per square metre of roof tile is well below 3 kW/h. This is excellent from an environmental point of view and helps conserve our planet's energy reserves.

 

> Environmentally compatible mining methods

Our obligation to recultivate the mining sites means that former quarries can once again harmonise with nature. Because these sites are closed to the public, they are often home to rare species of fauna and flora. Underground mines such as Altlay have no adverse effects at all on the landscape. All material excavated in the mine is used to fill up cavities. The waste produced during later processing is used to create floor coverings and bricks, for roadworks and as a neutral additive for the cement industry. The sawing and drilling processes require surface water, which is not chemically polluted and can be re-utilised internally after passing through a particle filter.

 

> An entirely natural product without pollutants

The fact that slate fully meets this requirement is of singular significance for all those employed in the mining and production of slate as well as for those engaged in the further processing of slate on building sites. In addition, house owners can be confident that a slate roof or facade is a healthy and naturally clean way to live. If a fire should break out there will be no harmful gases and acids.

 

> A long service life and no problems with disposal

The decision to use slate as a construction material represents a very meaningful investment for future generations. At the same time, maintenance costs are minimal. And no problems will arise when it eventually has to be disposed of. As a totally natural building material, slate has very low landfill requirements and is - of course - neutral in terms of its effect on the groundwater.