Forming levelling layer for esp. liq., plaster floor - from dry mix of hydrophobised light aggregate and calcium sulphate binder, sprayed with water

摘要

The use of a dry mixt. (I) for prodn. of a levelling layer (after spraying water onto the laid mixt.) under (esp. fluid) floor plasters is claimed. (I) consists of (by wt.) 10-40% hydrophobised mineral aggregate, selected from expanded perlite, pumice, foamed glass, lava, expanded clay and/or expanded vermiculite with a bulk density of 60-250 kg.cu.m. and less than 10 mm particle size; and 60-90% calcium sulphate source, esp. in the form of lump gypsum and/or alpha-hemihydrate. Prodn. of a levelling layer between a floor and an esp. fluid floor plaster comprises (a) applying the dry mixt., to the floor and distributing to obtain a level surface; and (b) spraying water onto the dry mixt. to form an in-situ set and hardened levelling layer. USE/ADVANTAGE - Esp. for restoration of old buildings. The dry mixt. can be easily packaged and transported, allows prodn. of levelling layers in an extremely simple manner without requiring compaction and, after water spraying, allows floor plaster applicaiton after an extremely short time.