Klebemörtel

Klebemörtel, or tile adhesive, is a cementitious mortar used to bond tiles and stone to substrates such as concrete, cement screeds, plaster, gypsum boards, and cementitious backer boards. In many formulations it is polymer-modified to improve adhesion, flexibility, and water resistance, making it suitable for interior and exterior tiling projects. Adhesives are typically sold as a powder to be mixed with water or as a ready-to-use premixed product.

Most Klebemörtel products are designed for thin-set or medium-bed applications. Thin-set mortars are applied in a thin layer (a few millimeters) to accommodate standard tile sizes, while medium-bed mortars allow for greater thicknesses to compensate for uneven substrates or large-format tiles. There are also frost-resistant and moisture-resistant variants for exterior use or wet areas. Some formulations include additives to extend open time or improve slip resistance during installation.

substrates and preparation: The substrate must be clean, sound, stable, and free from dust, oil, or loose matter. Porous substrates may require priming to control absorption. Irregular surfaces should be leveled, and movement joints must be respected according to the project requirements. For floors with moisture exposure, appropriate moisture barriers or waterproofing membranes may be required before applying Klebemörtel.

application and curing: The mortar is spread with a notched trowel to establish a uniform bed, and tiles are pressed in with slight twisting to achieve full bedding and adhesive contact. Open time and adjustments depend on the product and conditions. After installation, tiles are grouted once the adhesive has set as specified by the manufacturer.

standards and safety: Tile adhesives are generally manufactured to European or national standards, such as EN 12004, which define performance criteria. Handling precautions include avoiding skin or eye contact with cementitious materials, wearing protective gloves and eyewear, and following disposal guidelines.