Roof tile
Roof Structure and Tile Temperature Sensor Testing
Revised Roof Structure
The premise of the mock-up experiment originated from the excessive heat experienced in attic spaces due to the implementation of metal corrugated sheets into the roof structure. The mockup experiment entails the removal of these metal sheets, thereby reverting to traditional roof construction while ensuring the roof’s water-tightness and breathability. Two novel materials are introduced: a breathable moisture-barrier membrane and lime mortar bedding.
To preserve the authenticity of the existing roof structure, the timber rafters and purlins will be retained as much as possible. Alterations to the roof structure will include installing marine plywood layers on the top and bottom of the roof insulation, spaced with a small ‘penny gap’ to allow for air circulation between each panel. Additionally, a breathable moisture barrier will be incorporated to facilitate air movement while preventing water infiltration. The timber purlins that support the roof tiles will be reinforced with a lime mortar bed, which not only strengthens the adhesion of the roof rafters but also functions as the first layer of protection against penetrative rain as a breathable moisture barrier.
Surface Temperature Performance
The following data was collected on the mock-up located at the backyard of NUS ArCLab to test the surface temperatures of various roof tiles installed. Using the 88598 K 4ch K SD Logger, sensors were set up on the top surface of the roof tile (1CH), bottom surface of the roof tile underlayer (2CH), middle of the roof structure between the roof tiles and the moisture barrier (3CH), and the internal soffit of the mock-up structure.
Type 1 — Kamedani Tile
Surface temperature data was collected at 10-minute intervals between November 2024 – February 2025 and subsequently consolidated by taking the average temperature into 4 key time periods in a day to best identify the difference temperature between the hottest and coolest time of the day.
Type 2 — Malaysia Tile
Surface temperature data was collected at 10-minute intervals during the period of May - June 2025 and subsequently consolidated by taking the average temperature into 4 key time periods in a day to best identify the difference temperature between the hottest and coolest time of the day.
Conclusion
Considering the warm hours in a day (12:00-18:00 hrs), Kamedani tiles recorded a temperature difference of 4.6°C, while the Malaysian tiles recorded 7.8°C. Although the significant temperature difference may indicate the Malaysian tiles’ superior performance, a closer examination of the results reveals that the temperature of the tiles remains largely consistent along the layers of the roof structure above the moisture barrier and lime mortar bedding, with a temperature difference of 1.1°C, compared to Kamedani tiles, where the temperature difference is 2.6°C. This data suggests that Kamedani tiles are more effective in dissipating heat across the roof structure layers.
The achievement of a drastic temperature change between the top surface of the Malaysian tile and the soffit of the mock-up, resulting in cooler internal temperatures would have been attributed to the use of lime mortar bedding and the new roof breathable moisture barrier detailing rather than the roof tile itself.
Overall, temperature results from Kamedani tiles also reflected a lower temperature reading across all sensor locations within the mock-up roof layers. Therefore, as results have proven, Kamedani tiles have a much better thermal performance than its Malaysian counterpart.