Condensation on the wrong side of the vapor barrier!

[fredand44]

Hello!

(I thought I read a post about this a few weeks ago, but I can't find it now,)

I crawled onto my concrete slab in my little unheated crawl space under our porch yesterday and saw that I had gotten condensation on the inside of the vapor barrier at the bottom. Sigh!

I'm unsure how the moisture could have gotten in, I'm sure the material was dry in the summer when I installed the insulation and vapor barrier. (But then again, the humidity in the air is higher too.)

In the hall floor above, I have electric underfloor heating, so I assume that when the air in the floor heats up, it condenses against the cold vapor barrier at the bottom.

It never feels good with moisture, so now the question is if anyone has any idea how to fix this in a smart way. For example, make a few small holes that are then taped over, what do you think about that?

Best regards,
Fredrik

 

[Autodidak1]

There should not be a vapor barrier there; it should be under the hall floor (on the warm side). Remove it and add something like a wind protection fabric.

 

[fredand44]

Hello!
Thanks for the response!!
Now that you mention it, it feels obvious!!
The vapor barrier should be on the warm side, wrongly installed by me.
Now it's time to put up wind protection fabric instead!
Best regards,
Fredrik