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Hygrothermal assessment of internally added thermal insulation on external brick walls in Swedish multifamily buildings

Abdul Hamid, Akram LU and Wallentén, Petter LU (2017) In Building and Environment 123. p.351-362
Abstract

Proper and efficient renovation requires understanding the behavior of existing buildings and of different building materials. Analyzing hygrothermal measurements in two case studies, one with and the other without an internally added thermal insulation system, enabled us to identify factors of critical importance for further assessment through simulations, and to validate a hygrothermal simulation model of a solid brick masonry wall, a model used then to assess internally added thermal insulation systems of different types. A mold resistance design (MRD) model shows that, in connection with all internally added thermal insulation systems, the risk of mold growth is appreciable when brought on by solar driven vapor from the exterior.... (More)

Proper and efficient renovation requires understanding the behavior of existing buildings and of different building materials. Analyzing hygrothermal measurements in two case studies, one with and the other without an internally added thermal insulation system, enabled us to identify factors of critical importance for further assessment through simulations, and to validate a hygrothermal simulation model of a solid brick masonry wall, a model used then to assess internally added thermal insulation systems of different types. A mold resistance design (MRD) model shows that, in connection with all internally added thermal insulation systems, the risk of mold growth is appreciable when brought on by solar driven vapor from the exterior. This, if biological material is present in either of two critical areas, those of the boundary between the thermal insulation and either 1) the existing masonry wall, or 2) the exterior surface of an internally added vapor barrier. Furthermore, assessments of corrosion risks are conducted for two critical placements of the bed-joint reinforcement. At a depth of 30 mm from the exterior surface, the corrosion risk was found to be less with use of capillary-active vapor-open systems than when no thermal insulation was employed, other systems increase the corrosion risk. At a depth of 90 mm, all thermal insulation systems increase the corrosion risk. Excluding precipitation uptake eliminates all risks, showing that this is the most crucial factor. Solutions that limit this uptake or increase the drying-out rate should thus be considered beneficial.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Brick, Hygrothermal, Insulation, Masonry, Moisture, Renovation
in
Building and Environment
volume
123
pages
12 pages
publisher
Elsevier
external identifiers
  • scopus:85030474807
  • wos:000411847600027
ISSN
0360-1323
DOI
10.1016/j.buildenv.2017.05.019
language
English
LU publication?
yes
id
f621608c-3d03-415b-8e80-6c1bf29a2c7b
date added to LUP
2017-10-16 11:52:07
date last changed
2018-01-16 13:23:10
@article{f621608c-3d03-415b-8e80-6c1bf29a2c7b,
  abstract     = {<p>Proper and efficient renovation requires understanding the behavior of existing buildings and of different building materials. Analyzing hygrothermal measurements in two case studies, one with and the other without an internally added thermal insulation system, enabled us to identify factors of critical importance for further assessment through simulations, and to validate a hygrothermal simulation model of a solid brick masonry wall, a model used then to assess internally added thermal insulation systems of different types. A mold resistance design (MRD) model shows that, in connection with all internally added thermal insulation systems, the risk of mold growth is appreciable when brought on by solar driven vapor from the exterior. This, if biological material is present in either of two critical areas, those of the boundary between the thermal insulation and either 1) the existing masonry wall, or 2) the exterior surface of an internally added vapor barrier. Furthermore, assessments of corrosion risks are conducted for two critical placements of the bed-joint reinforcement. At a depth of 30 mm from the exterior surface, the corrosion risk was found to be less with use of capillary-active vapor-open systems than when no thermal insulation was employed, other systems increase the corrosion risk. At a depth of 90 mm, all thermal insulation systems increase the corrosion risk. Excluding precipitation uptake eliminates all risks, showing that this is the most crucial factor. Solutions that limit this uptake or increase the drying-out rate should thus be considered beneficial.</p>},
  author       = {Abdul Hamid, Akram and Wallentén, Petter},
  issn         = {0360-1323},
  keyword      = {Brick,Hygrothermal,Insulation,Masonry,Moisture,Renovation},
  language     = {eng},
  month        = {10},
  pages        = {351--362},
  publisher    = {Elsevier},
  series       = {Building and Environment},
  title        = {Hygrothermal assessment of internally added thermal insulation on external brick walls in Swedish multifamily buildings},
  url          = {http://dx.doi.org/10.1016/j.buildenv.2017.05.019},
  volume       = {123},
  year         = {2017},
}