Exterior Tiles

[David Lam]

I haven't been able to find a satisfactory post on this forum. I may have missed it so please direct me if it exists.

I am attempting to model a building with external tiles (unknown material - I have asked). There is no material in WUFI for this. The exterior surface option of using 2m sd doesn't make sense as I would expect the tiles to keep the rain off pretty well.
I'm using WUFI Pro so can't model the grout (that's the bit between tiles) well, but I'm less concerned about that.
What I need is a sensible way to model the tiles, and there doesn't appear to be one.
Can you help please?

[Manfred Kehrer]

Hello David,
the sd value of 2m refers to the vapor permeance and has nothing to do with the rain absorption/deflection, but you can use a user defined sd value to account for any painting if exists.
I suggest to use a brick material to address the water sorption characteristics.
Best,

[Thomas]

Hi David,

the tiles in the drop-down list are supposed to be glazed and thus impermeable to vapour transfer. However, the mortar in the joints between the tiles is vapour-permeable, and the "2 m" suggested by the drop-down list refer to the vapour permeability of those joints, taking their fractional area on the wall into account (in other words, it is a weighted average of the impermeable glazed tiles and the permeable mortar in the joints).

See here for a short earlier discussion: Perm ratings for ceramic and porcelain tiles

Regards,
Thomas