Air Leakage Assumption on flat concrete roof?

[Andreas Hauser]

Hello,

I have a question concerning the air leakage assumption at a flat concrete roof.
At wooden roofs I usually add a moisture source at an apropriate place on the outside of the roof. I use the "air infiltration model IBP" and choose an "air tightne class".
At larger concrete roofs, we have penetrations of the roof and gaps. I guess, there exists air leakages, too.
Would you use the same "air infiltration model IBP" and choose an "air tightne class" as we do it at wooden roofs?

Thanks!

[Christian Bludau]

Hello Andreas,

you could use the air infiltration source here, so you have an additional moisture load in your insulation to be on the save side. In reality there probably will be no infiltration through your concrete ceiling.

Christian