Investigation of the moisture conditions of the building envelope of sand-lime brick walls insulated with expanded polystyrene of various grades

• Main Authors: Myskin, S. M., Koroleva, T. I., Ivachev, M. A.
• Format: Conference Proceeding
• Language: English
• Subjects: Air temperature; Bricks; Building envelopes; Condensates; Freezing; Heat loss; Insulation; Load bearing elements; Moisture effects; Polystyrene resins; Sand; Thickness; Walls; Water vapor
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0145492

With a proper choice of material for thermal insulating layer of the outer building envelope, you can exclude the possibility of water vapor condensation in the thickness of the structure and as a consequence at the design stage to avoid adverse effects (destruction of fences, reducing heat transfer resistance and increasing heat loss of buildings and structures) during their further use [1 - 2]. The purpose of this study is to choose the most effective brand of expanded polystyrene insulation for insulating the load-bearing layer of a wall made of sand-lime brick. 4 variants of insulation were investigated: 1) Expanded polystyrene according to TU 6-05-11-78-78; 2) Expanded polystyrene “Radoslav” (Pereslavl-Zalessky), plate 18; 3) Expanded polystyrene from BASF “Styropor PS 15”; 4) Extruded polystyrene from BASF “Styrodur 2500 C”. For all variants, the possibility of moisture condensation in the thickness of the enclosing structure in the range of outside air temperatures from -9.9 °C to -27 ° C was determined by calculation and analytical method. According to the results of the study, it was found that the insulation of sand-lime brick walls with insulation materials numbers 2 and 4 have the worst indicators of the moisture conditions and the probability of freezing occurs already when the outside temperature -15 °C, and at -27 °C moisture condensation zone is observed in 4 sections. Wall structures insulated with materials numbered 1 and 3 have better performance on the moisture balance, the possibility of condensation occurs at lower temperatures of -18 °C and -17 °C, respectively, and the condensation zone is formed at the junction of insulation, which leads to less likely to its destruction. It was also found that when insulated with any of the above options of insulation material in the bearing layer of the wall condensation zone and the strength of the enclosing structure will not be broken because of the destruction of masonry due to its freezing.