I want to simulate the a roof with roofing felt as DensElement™ BARRIER SYSTEM from wufi database.
The DensElement™ BARRIER SYSTEM is in the WUFI material database and should be watertight but lets vapour out through the construction according to its technical guide.
- I need the Sd-value [m] or the vapour transfer coefficient [kg/m2sPa] for the barrier system in WUFI2D. In the technical guide of DensElement the vapour transfer coefficient is given as:
Permeance: US perms (ng/m2•s•Pa) ≤24 (1823).
Does that mean I can use the vapour transfer coefficient at the exterior surface as: 1.823e-9 kg/m2sPa ?
- As seen in the figure below the thickness of the den-element should be 0.01588m. If I want to include the dens in my simulation is it neccessary to adjust the thickness of the dens element to 0.01588m?
- Is it reasonable to use this material as a roofing felt on top of a gypsum roof board air tight roof.
https://denselement.com/wp-content/uplo ... _Guide.pdf