Abstract
Cold pitched roofs, with their form of construction situating insulation on a horizontal ceiling, are intrinsically vulnerable to condensation. This study reports the results derived from using a simulation package (Heat, Air and Moisture modelling tool, or HAM-Tools) to investigate the risk of condensation in cold pitched roofs in housing fitted with a vapour-permeable underlay (VPU) of known characteristics. In order to visualize the effect of the VPUs on moisture transfer, several scenarios were modelled, and compared with the results from a conventional bituminous felt with high resistance (200 MNs/g, Sd = 40 m). The results indicate that ventilation is essential in the roof to reduce condensation. However, a sensitivity analysis proved that reducing the overall tightness of the ceiling and using lower-resistance VPUs would help in controlling condensation formation in the roof.
Original language | English |
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Pages (from-to) | 117-128 |
Number of pages | 12 |
Journal | Building Research and Information |
Volume | 37 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Jan 2009 |
Keywords
- condensation
- cold pitched roofs
- construction