Please help , mold!

[leeroyjinx]

hi everyone i have a metal pole barn in Eastern plains of colorado that i grow vegetablets in . I recently installed insulation with poly white facing to help keep garage warm, however it seemes where ever the insulation goes up there is moisture that buids up on the inside of the metal beteween fiberglass and the metal. this water beeds up and has been creating mold problems. Days when it snows and drops below 32 all day with high humidiyt seem to be the worste days, not so bad even today , relatively foggy day and temp below 45 all day.
The parts that dont have insulation dont drip but i do have to keep a fan on them.
i. do not have dehumidifier in there and i have yet to put 2x4 on the bottom of the insulation that touches the concretet, so maybe the moisture from the concrete or the temp difference the insulation is 8 inche and the gaps all around are 7 inches, i was told if it touches the metal all the way it shouldnt have this problem, but i dont see how that is possible with 2x4 in the way that hold the metal shell to the wood., anyways i was wondering what to do, i was thinking about taking it down and applying spray foam, the metal just seems impossible for not to sweat loke this, i dont know what to do , i have spent alot of time installing this insulation for a 32x30 pole barn.

 

[Roberts210]

I can't tell from your description exactly what you have built there. But it sounds like you will have to somehow create some air flow between the insulation and the metal, so the moisture can move out of that space before it condenses.

It would help a lot if you would post some pictures.

 

[2oolhound]

You need to post this in the garage build section here:

http://www.garagejournal.com/forum/forumdisplay.php?s=&daysprune=-1&f=26

Sounds like you need air space between metal siding and the insulation.

 

[Jake40]

If you have an air space between the insulation and the metal it needs to be vented. If it cannot breathe with temperature change and humidity change it will sweat.

 

[Al Borland]

First, you need a vapor barrier between the insulation and the heated space. That needs to be sealed to prevent airflow.
As far as mold goes, it needs water and food to grow. What surfaces are molding?

 

[matt_i]

Fans are your friend when you have essentially a terrarium with sealed heat and moisture for and from the plants. Imo a dehumidifier will work but its going to be going wide open forever and its directionally wrong for plants.

 

[Infinia]

hi everyone i have a metal pole barn in Eastern plains of colorado that i grow vegetablets in .

Colorado Vegetables


use moar insulation*
or perhaps add vapor barrier + air space in addition to a plastic layer
E.g. force the dew drops to form on the outside layer

*sealed air space is the cheapest insulation

 

[Jake40]

Colorado Vegetables


use moar insulation*
or perhaps add vapor barrier + air space in addition to a plastic layer
E.g. force the dew drops to form on the outside layer

*sealed air space is the cheapest insulation

The insulation he used has a vapor barrier on it.

 

[Infinia]

The insulation he used has a vapor barrier on it.

IDK does he?
backwards install

4. Use an air/moisture barrier layer.
If you plan to heat or cool your building, use an air barrier, such as Tyvek, on the outside of the insulation, and poly on the inside, to minimize unwanted airflow.
Make sure your builder knows how to properly seal the Tyvek around doors and windows. Proper sealing will keep both air and water from getting into your insulation and the building materials of your wall.
Good air sealing will keep you from losing money on the utilities you pay for to make the inside of your building comfortable.

 

[MikeF2316]

The insulation he used has a vapor barrier on it.

But the vapour barrier needs to be 100% continuous. That's the problem. The humidity just goes between the pieces of insulation and hits the cold metal. That's the reason you see complete sheets of plastic sealed with tape at any edges over the insulation in new house construction.