kipsislaastien

Kipsislaasti, or gypsum plaster, is a plaster material whose binder is gypsum (calcium sulfate dihydrate). It is produced by calcining gypsum to the hemihydrate form, grinding it to a fine powder, and then mixing with water to form a workable paste. Modern kipsislaasti may include additives such as retarders, accelerators, fibers, or fine aggregates to adjust workability, strength, or texture. It is primarily used for interior walls and ceilings, where it provides a smooth finish ready for painting or wallpaper.

Application and use are typically in one or more coats, depending on the substrate and the desired surface quality. Substrates include masonry, concrete, gypsum boards, and timber structures with appropriate lath or mesh. Finishing coats are usually thin, while base coats may be applied in thicker layers to level irregularities. Gypsum plaster can be used as a base for veneers or decorative finishes and is compatible with standard interior coatings.

Properties and performance: gypsum plaster is lightweight, provides good surface quality, and exhibits relatively low shrinkage. It sets quickly at room conditions, enabling faster construction schedules. It is non-hydraulic, meaning its hardening relies on moisture; it is also relatively vulnerable to moisture and water damage, so external or high-humidity applications require moisture protection or alternative binders. Storage and handling require protection from dampness to avoid premature setting.

Variations include standard powder plasters, ready-mixed formulations, and some additives or fibers to improve toughness or modify setting behavior. In some cases, hydraulic gypsum plasters with special additives offer better performance in damp environments.