Moisture is one of the major factors in the physical deterioration processes of building facades.
Physical deteriorations are typically caused by restrained moisture movements and freezing or are connected to
chemical or biological attacks. Changes in moisture and temperature lead to the swelling and shrinking of
building materials. Freezing of water in pores and cracks leads to an increase in volumes and causes scaling
and spalling of materials. The continuous monitoring of temperature and relative humidity provides significant
information about the long-term performance of buildings. Documenting the performance of repaired facades
through this monitoring can enhance our understanding of the long term deterioration of materials and the
changes in the structural behaviour due to aging.
One objective of the research was to test the new possibilities offered by ICT (Information and Communication
Technology) in the real estate and construction sector. For that purpose, a new relative humidity and thermal
monitoring network system (RHT-MNS) was developed. The (RHT-MNS) is useful for assessing the performance
of repaired building facades. It also gives information about the physical functioning of facades.
A field study for testing the RHT-MNS was carried out to monitor the temperature and relative humidity of a
facade that was repaired by adding external mineral wool insulation and a rendering system (Sto AG, Sto Therm
Vario, Finexter Oy) consisting of 6 mm of rendering coat and glass fibre mesh. The monitoring was carried out
at regular intervals of 15 minutes since the year 2004.
The results of relative humidity and temperature monitoring provide an opportunity to have a close look at the
hygrothermal performance of the building facade. The results show that the original facade structure is drying
after adding the external wall insulation and rendering system.
The RHT-MNS monitoring network system has proven to be a new successful method for monitoring the thermal
and moisture conditions in repaired building facades. The RHT-MNS monitoring network system is also reliable,
inexpensive, fast to assemble and easy use.