Strategies for Enhanced Energy Efficiency and Moisture Management in Brick–AAC Cavity Walls

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceedingpeer-review

Abstract

In Sweden, cavity walls constructed with autoclaved aerated concrete (AAC) inner leaves and clay brick outer leaves were a common design choice during the 1950s to 1970s. These walls often result in relatively extensive heat losses, leading to reduced indoor thermal comfort. Further, moisture-related issues like frost damage and interior dampness are reported for this wall type. This indicates the importance of enhancing the hygric and thermal performance of such walls. Since preservation of the protected facade due to heritage values limits external interventions, interior insulation becomes a primary focus for energy efficiency improvements. This study aims to explore various maintenance and renovation measures to enhance the performance of these walls, namely a) repointing the outer leaf (face bricks), b) adding interior insulation with different properties, and c) combining interior insulation with repointing. The study employs hygrothermal simulations for Gothenburg, the location with one of the highest exposure to wind-driven rain (WDR) in Sweden. The results highlight that an efficient way to improve the wall condition, a balance between moisture accumulation and heat loss, is to add vapor-open insulation followed by repointing, especially for walls in a deficient condition. Repointing alone effectively reduces moisture accumulation for cavity walls with brick masonry in a deficient condition, with a limited impact on improving thermal comfort. XPS insulation, a vapor-tight system, reduces heat loss but increases moisture in the AAC layer, posing potential moisture-related issues. Adding capillary-active insulation followed by repointing improves thermal comfort without significant moisture accumulation in the AAC layer.
Original languageEnglish
Title of host publication18th International Brick and Block Masonry Conference
Place of PublicationSwitzerland
PublisherSpringer Nature
Pages804-819
Number of pages16
Volume1
ISBN (Electronic)978-3-031-73314-7
ISBN (Print)978-3-031-73313-0
DOIs
Publication statusPublished - 2025

Subject classification (UKÄ)

  • Building Technologies

Free keywords

  • Repointing
  • Masonry cavity wall
  • Internal insulation
  • Dampness
  • Autoclaved aerated concrete (AAC)
  • Moisture content
  • Heat loss

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