Magnesium-oxide boards cause moisture damage inside facades in new danish buildings

Author(s): Kurt Kielsgaard Hansen, Tommy Bunch-Nielsen, Bent Grelk, Carsten Rode
Paper category: Proceedings
Book title: Proceedings on International RILEM Conference on Materials, Systems and Structures in Civil Engineering Conference segment on Moisture in Materials and Structures
Editor(s): Kurt Kielsgaard Hansen, Carsten Rode and Lars-Olof Nilsson
ISBN: 978-2-35158-178-0
e-ISBN: 978-2-35158-179-7
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 164 - 175
Total Pages: 10
Language : English

Abstract: Magnesium oxide board, “MgO-board”, is a factory-made sheathing board product, which has been widely used in the last 5 years in ventilated facades on new or renovated buildings in Denmark. In winter 2014/15, a number of problems began to appear with these boards since the boards and adjoining building elements seemed to suffer from some sort of disease, which manifested itself by damages such as significant moisture, boards leaking salty water (‘tears’), corrosion of fittings and anchors and mould growth.
The damages were caused by the fact that MgO-boards absorb moisture from outside air in periods with high outdoor humidity (90-100% RH) and form water drops on the surfaces. The drops contain a high amount of soluble chloride ions and appear on the surfaces of the boards and may often run down the boards and to adjacent structures. Metal fixtures for the MgO- and siding boards may corrode heavily within a few years. The binder in MgO-boards is formed by chemical reaction between MgO and MgCl2, known as magnesium oxychloride cement or Sorel cement. Also organic matter can be found in the material. The paper presents results of investigations of properties for moisture ab- and desorption curves and transport of MgO-boards.

Online publication : 2016
Publication type : full_text
Public price (Euros) : 0.00