Hygrothermal Behavior of Thin-Walled CLT Folded Plate Envelopes under Intermittent Heating Regimes
DOI:
https://doi.org/10.38027/jsalutogenic_vol5no1_6Keywords:
Cross Laminated Timber (CLT), Folded Plate, Building Physics, Barkat Prototype, Wooden StructuresAbstract
Current building physics regulations, such as TS 825, prescribe heavy insulation based on continuous-heating assumptions. Yet, the hygrothermal consequences of the fluctuating regimes of periodically used buildings remain insufficiently characterized, particularly for thin-walled Cross-Laminated Timber (CLT) envelopes. This study evaluates the hygrothermal performance of the "Barkat Folded Plate" CLT system under a measured periodic-use scenario by triangulating exploratory field observations, steady-state digital calculation (Ubakus, Glaser method), and 1/1 scale dynamic testing. Observations in periodically heated mosques of Istanbul’s Fatih district showed indoor temperatures of 14–17°C rather than the regulatory 20–22°C; these data defined the boundary conditions for Simplified Hot Box experiments (15-hour night cycle, ΔT ≈ 17°C) on three stratification strategies. The diffusion-open Type-1 released moisture (−12 g), acting as a hygroscopic buffer; the bitumen-sealed Type-2 gained +15 g, confirming vapor-trap behavior while remaining far below the 20% fiber-saturation threshold associated with biological degradation; the hybrid Type-3 buffered +14 g within the timber without interstitial condensation. Within this single-cycle experimental scope, the findings indicate that diffusion-open and vapor-retarded timber sections manage periodic moisture loads more adaptively than heavily insulated, diffusion-closed assemblies, suggesting that envelope requirements for periodic-use functions may merit differentiation rather than uniform prescription.
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Copyright (c) 2026 Muhammed Emin Akyurek, İbrahim Agah Tastemir (Author)
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