Slate Shingle Roofing

[rrenaud]

I am trying to model a roof assembly using slate shingle roofing. The assembly is slate on air space on alphalt imprgenated felt on 1" nominal spruce planking. The permeability of the slate is very low, however there is significant gaps between the slates to say the air space behind is ventilated.

I have modeled this using a 10mm air space ventilate to the exterior at 1AC/hour. When I check the isopleth monitoring points for the materials it indicates a probability of mold growth. When the roof is actually deconstructed in the field, we are not finding the mold growth.

Any advice would be helpful.

[Manfred Kehrer]

Dear rrenaud,

if the points in the isopleth diagram are beyond the LIMs, this means only that mould growth is not out of the question.

A special investigation with WUFI Bio
(http://www.hoki.ibp.fhg.de/wufi/downloads_e.html)
should be done then.