Properties of magnesium oxide boards used as sheathing in exterior walls

Stefanie Wøhler Nielsen, Carsten Rode, Tommy Bunch-Nielsen, Kurt Kielsgaard Hansen, Wolfgang Kunther, Bent Grelk

Research output: Contribution to journalConference articleResearchpeer-review

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Abstract

Sheathing boards based on magnesium oxide (MgO) became very popular in the Danish market around the year 2010. However, it was realized a few years later that they condensed humidity from ambient air. The leakage from the boards led to severe problems with corrosion of metallic components and moisture uptake and degradation of wooden members. The boards have been banned from use in the Danish market since 2015, while damage cases valuing around 370 million EUR still need to be reconciled [1]. The binder in MgO board is formed by a chemical reaction between MgO and MgCl2. However, MgSO4 is a possible alternative to MgCl2, and such boards may have smaller moisture uptake, to reduce this issue. This paper gives an account of recent activities to compare properties of MgO boards, based on chlorides or sulphates. The investigations comprise: (1) Analysis of elemental composition and crystalline components, (2) Examination in optical microscope and scanning electron microscope, (3) Determination of moisture retention and water vapour permeability, (4) Analysis of chemical composition of leaked salt water from boards, and (5) Visual observation of decomposition and determination of dry mass change after exposure to high humidity.
Original languageEnglish
Article number02091
JournalMATEC Web of Conferences
Volume282
Number of pages6
ISSN2261-236X
DOIs
Publication statusPublished - 2019
Event4th Central European Symposium on Building Physics - Prague, Czech Republic
Duration: 2 Sep 20195 Sep 2019
Conference number: 4
https://www.cesbp2019.org/

Conference

Conference4th Central European Symposium on Building Physics
Number4
CountryCzech Republic
CityPrague
Period02/09/201905/09/2019
Internet address

Bibliographical note

This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/)

Cite this

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title = "Properties of magnesium oxide boards used as sheathing in exterior walls",
abstract = "Sheathing boards based on magnesium oxide (MgO) became very popular in the Danish market around the year 2010. However, it was realized a few years later that they condensed humidity from ambient air. The leakage from the boards led to severe problems with corrosion of metallic components and moisture uptake and degradation of wooden members. The boards have been banned from use in the Danish market since 2015, while damage cases valuing around 370 million EUR still need to be reconciled [1]. The binder in MgO board is formed by a chemical reaction between MgO and MgCl2. However, MgSO4 is a possible alternative to MgCl2, and such boards may have smaller moisture uptake, to reduce this issue. This paper gives an account of recent activities to compare properties of MgO boards, based on chlorides or sulphates. The investigations comprise: (1) Analysis of elemental composition and crystalline components, (2) Examination in optical microscope and scanning electron microscope, (3) Determination of moisture retention and water vapour permeability, (4) Analysis of chemical composition of leaked salt water from boards, and (5) Visual observation of decomposition and determination of dry mass change after exposure to high humidity.",
author = "Nielsen, {Stefanie W{\o}hler} and Carsten Rode and Tommy Bunch-Nielsen and Hansen, {Kurt Kielsgaard} and Wolfgang Kunther and Bent Grelk",
note = "This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/)",
year = "2019",
doi = "10.1051/matecconf /20192820202091",
language = "English",
volume = "282",
journal = "MATEC Web of Conferences",
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}

Properties of magnesium oxide boards used as sheathing in exterior walls. / Nielsen, Stefanie Wøhler ; Rode, Carsten; Bunch-Nielsen, Tommy; Hansen, Kurt Kielsgaard; Kunther, Wolfgang; Grelk, Bent.

In: MATEC Web of Conferences, Vol. 282, 02091, 2019.

Research output: Contribution to journalConference articleResearchpeer-review

TY - GEN

T1 - Properties of magnesium oxide boards used as sheathing in exterior walls

AU - Nielsen, Stefanie Wøhler

AU - Rode, Carsten

AU - Bunch-Nielsen, Tommy

AU - Hansen, Kurt Kielsgaard

AU - Kunther, Wolfgang

AU - Grelk, Bent

N1 - This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/)

PY - 2019

Y1 - 2019

N2 - Sheathing boards based on magnesium oxide (MgO) became very popular in the Danish market around the year 2010. However, it was realized a few years later that they condensed humidity from ambient air. The leakage from the boards led to severe problems with corrosion of metallic components and moisture uptake and degradation of wooden members. The boards have been banned from use in the Danish market since 2015, while damage cases valuing around 370 million EUR still need to be reconciled [1]. The binder in MgO board is formed by a chemical reaction between MgO and MgCl2. However, MgSO4 is a possible alternative to MgCl2, and such boards may have smaller moisture uptake, to reduce this issue. This paper gives an account of recent activities to compare properties of MgO boards, based on chlorides or sulphates. The investigations comprise: (1) Analysis of elemental composition and crystalline components, (2) Examination in optical microscope and scanning electron microscope, (3) Determination of moisture retention and water vapour permeability, (4) Analysis of chemical composition of leaked salt water from boards, and (5) Visual observation of decomposition and determination of dry mass change after exposure to high humidity.

AB - Sheathing boards based on magnesium oxide (MgO) became very popular in the Danish market around the year 2010. However, it was realized a few years later that they condensed humidity from ambient air. The leakage from the boards led to severe problems with corrosion of metallic components and moisture uptake and degradation of wooden members. The boards have been banned from use in the Danish market since 2015, while damage cases valuing around 370 million EUR still need to be reconciled [1]. The binder in MgO board is formed by a chemical reaction between MgO and MgCl2. However, MgSO4 is a possible alternative to MgCl2, and such boards may have smaller moisture uptake, to reduce this issue. This paper gives an account of recent activities to compare properties of MgO boards, based on chlorides or sulphates. The investigations comprise: (1) Analysis of elemental composition and crystalline components, (2) Examination in optical microscope and scanning electron microscope, (3) Determination of moisture retention and water vapour permeability, (4) Analysis of chemical composition of leaked salt water from boards, and (5) Visual observation of decomposition and determination of dry mass change after exposure to high humidity.

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