Thread: Condensation in metal shed

Originally Posted by BobL

If gas is going to be burned inside a building and exhaust is not flued or vented it's going to add massive amounts of water to the shed (not to mention loads of CO2).

I still don't have any active ventilation/dehumidifying, or air temperature/humidity logging.


There was heavy rain & wind on Sunday. New internal factory leak in one spot on Monday. A few days of no rain, so steps/ground under the leak mostly dried out.

A cold Thursday night (down to 6°), and Friday late morning, DRIP, DRIP, DRIP from the edge of the internal insulation blankets:

IMG_3016.jpg IMG_3017.jpg


So, exactly one year later, I guess the conditions are identical? At least I got better photos this time.

I'm going to try, in a few different areas inside;

1) Shoving something under the blanket, near that edge, so that it is more air-tight above the blanket.
My hope is that less internal air circulating above the blanket means less condensation on the cold roofing sheet above it.

2) Duct sealing tape, on the top of the metal, and folded to seal the edge of the blanket to the roofing sheet.

3) Some thick foam along that exposed edge of roofing sheet, so that it is not available for damp inside air to condense on.

Hi Guys,

JMTPW, Sprayed foam insulation directly onto the dry metal roofing works much better than a loose insulation blanket, though the adhesive backed stuff works well but is really only suitable for relatively small areas.

There is a new warehouse being built near me and they are spraying the roof sheets with an expanding foam material. I understand that it is to be a fully automated building with robots doing the running about. I'm only guessing but the word "Amazon" comes to mind !