Measurements behind Internal Insulation on Solid Masonry Walls with Different Orientations and Degrees of Repair in a Danish Multi-story Building

Lies Vanhoutteghem,Britt Haker Høegh,Thor Hansen,J Kurnitski,T Kalamees

doi:10.1051/e3sconf/202017201008

Lies Vanhoutteghem, Britt Haker Høegh + Show 3 more

Open Access

https://doi.org/10.1051/e3sconf/202017201008

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Abstract

Internal insulation is used in many heritage buildings to ensure a better indoor environment and reduce energy use. This article describes measurement results from installing an internal insulation system in a Danish multi-story building. The internal insulation system consists of a fully glued vapour tight insulated plasterboard. To reduce the risk for wood decay and mould growth at the wooden beam ends in the floor construction, a 100-200 mm uninsulated gap was left above and below the floor construction. Measurements include the effect of orientation, degree of façade repair and influence of indoor moisture content. Results show in general acceptable hygrothermal conditions behind the insulation system. However, a gradual increase in relative humidity at sun-exposed walls was registered due to ‘summer condensation’. The degree of surface repair also showed an influence on relative humidity levels during this period. At the uninsulated gap above the floor, a higher moisture content indoor resulted in a higher relative humidity, though without exceeding the threshold for mould growth. However, a large temperature range was registered. The influence of the uninsulated gap on reducing the risk of wood decay and mould growth at the beam ends could therefore not unambiguously be confirmed.

Highlights

Internal insulation is often the only suitable measure to reduce the energy use and ensure a better indoor climate in heritage buildings, or buildings worthy of preservation
Results in this paper describe the design and measurement data from an internal insulation system in one of the projects case buildings
To assess the hygrothermal performance of the internal insulation system, results have been compared to the critical moisture level for mould growth [15]

Summary

Introduction

Internal insulation is often the only suitable measure to reduce the energy use and ensure a better indoor climate in heritage buildings, or buildings worthy of preservation. Applying internal insulation reduces the inside temperatures and the drying potential of the original walls, which increases the risk for interstitial condensation [1], and risk of mould growth and wood decay at the embedded beam ends. The choice of insulation system, and its effect on hygrothermal behaviour of the walls and beam ends is subject to much research, as systems for internal insulation or continuously evolving [3,4,5,6,7,8]. Besides the choice of insulation system, the performance of the existing façade, and the influence of wind driven rain have a large impact on the hygrothermal behaviour of the walls [9]. Influence of façade repair is instead considered

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Conclusion