Until recently, buried structures and underground structures were not always thermally insulated. However, taking into account the tendencies for the development of underground space and in order to increase the efficiency of operation, it became necessary for additional insulation.
Research at the Research Institute of Building Physics of the Russian Academy of Architecture and Building Sciences when simulating the operating conditions of heat-insulating materials as part of facade systems confirmed the need to insulate the buried part of the external walls of heated structures.
Moreover, the insulation of underground structures, at least buried by at least 1 meter, became mandatory after the entry into force of Amendment No. 1 to SP 50.13330.2012 “Thermal protection of buildings”. This happened on June 15, 2019. Now, to calculate the reduced resistance to heat transfer of a part of a wall located below ground level to a depth of at least 1 m, the same standardized value should be used as for a wall located above ground level.
Previously, designers, who were aware of the need to insulate underground structures, acted in this way. There was no standard value for calculating the thermal insulation of underground structures, and they were guided by the standards for aboveground structures. In other words, this change legitimized the existing practice.
When choosing a material for insulating underground structures, the main factor, in addition to heat-shielding properties, is moisture resistance. Foundations and other elements of a building located underground are in constant contact with both groundwater and moisture that enters the soil due to precipitation.
Of the most common modern insulation materials, only one material has the required moisture resistance. This is extruded polystyrene foam, the water absorption of which does not exceed 0.5% by volume, i.e., essentially zero. Other common heat-insulating materials with a fibrous and granular structure, under the influence of moisture, not only lose their heat-shielding ability, but also collapse.
The first domestic extruded polystyrene foam has been produced since 1998 by the PENOPLEX company. During this time, a wealth of experience has been accumulated in the manufacture and use of the material, including for thermal insulation of underground structures, where especially durable brands of insulation PENOPLEX are successfully used.®GEO, PENOPLEKS®45, PENOPLEKS®45C.
