Water absorption coefficient of fiber glass

[WEI LI]

Hi all,

Could anybody please tell me the estimated water absorption coefficient of fiber glass?
I think I have already searched through the internet but nothing popped out.
Or any other resources which I can get the liquid transport properties of fiber glass from?

Cheers

[Christian Bludau]

Dear Wei Li,

i would assume that fiber glass materials have no significant water absorption and hardly any liquid transport. I think liquid water absorption only takes place in imperfections.

What kind of fiberglass building material are you looking at?

Christian

[WEI LI]

Hi Christian,

Thanks for the reply.
I have the same thought with you. I am considering a 140 mm fiber glass insulation in roof.
Normally, there are facers on both sides of the fiber glass insulation, right?

[Christian Bludau]

Hi Wei Li,
I thought you are talking about something like epoxy-glass resin.
Fiber glass insulation is hydrophobic, so there is no water absorption. Liquid water will run through / off. There are a couple of fiber glass insulation materials in the database, search for "mineral wool".

Some of them have facers, but they are not included in the material dataset. If there is a membrane, you have to insert that as extra layer in the calculation.

Christian

[WEI LI]

It is really helpful. Thanks a lot, Christian.