FIELD: chemistry.
SUBSTANCE: invention relates to a method of making underlay in buildings. In the said method which involves mixing components of a dry construction mixture and water, laying the obtained mixture and drying, laying is carried out in two steps, where a dry construction mixture containing the following components given in vol. % is used at the first step: porous material selected from a group comprising: polystyrene foam, crushed limestone wastes, vermiculite, pearlite and expanded clay 48.0-69.0, slaked lime 0.76-0.84, technical lignosulphonates 0.1-0.13, sodium tripolyphosphate 0.02-0.03, G3-G6 gypsum binder - the rest. A dry construction mixture containing components in the following ratio given in vol. % is used at the second step: quartz sand 25-50, plasticiser 0.38-0.42, slaked lime 2.5-2.75, sodium tripolyphosphate 0.18-0.22, G13 and G16 gypsum binder - the rest. Laying is done successively, starting with a first layer with thickness of 20-300 mm from a mixture of water and components of the dry construction mixture from the first step, and then a 5-30 mm thick second layer on the hardened first layer from a mixture of water and components of the dry construction mixture from the second step, where when mixing water and components of the dry mixture from the first step porous material is first mixed an aqueous mixture from technical lignosulphonates and sodium tripolyphosphate and the rest of the components of the dry mixture are then added. When mixing water and components of the dry mixture from the second step, quartz sand is first mixed with an aqueous mixture from plasticiser and sodium tripolyphosphate and the rest of the components are then added. The second layer is dried at 20°C until complete hardening.
EFFECT: increased strength and water resistance, improved heat- and sound insulation properties.
3 ex
