Metal Garage Roof

[The_Doctor]

Hi there hope someone can give me some advice/guidance.

I recently extended my garage and re roofed it with corrugated metal sheeting. With the weather being as cold as it has been for the past few days i was getting serious condensation build up on the inside of the roof.

I have now completely covered the inside of the metal roof using 4'x2' sheets of ecotherm insulation. I stuck them up with expanding foam - keeping them as tightly together as possible.

In places the condensation had iced up, so i used a heat gun to melt this and dried them as much as possible before sticking up the sheets.

Now what has caused me concern is this morning when i went into the garage i still had drips seeping thru where the sheets meet, i know i have to cover these 'joints' with the foil type sticky tape (my mission for tommorow) - but should i have had build up of condensation above these sheets?

What can i do to solve this problem. I am going to be storing tools and electrical bits and pieces in the garage and dont want to end up damaging them with drips from the condensation!!

Also - where the metal sheets rest on the wallplate at the top of the slope side there is -on the outside - a gap between the flashing and the 'raised' parts of the corrugated sheeting - could this be causing the condensation, i was thinking of spraying some expanding foam in this gap all the way along the roof - will that help in anyway??

any help or pointers would be appreciated.

Thanks

Maxi

 

[Deluks]

As long as the moist air in the room can 'get to' the metal sheets you will still have condensation. You have to either remove any moisture source from the room itself, or make sure that the insulation is continuous and tied in with the wall insulation which erm, you don't seem to have.

Put down some old towels on the floor to catch the existing drips, then remove the towels and dry them out/repeat.

As you've only had the insulation up for a day or two, you might even find that if you leave it a few weeks the problem resolves itself.

The sprayfoam idea may or may not help. On one hand you will be reducing what could be essential ventilation for the structure, on the other hand it might help raise the room temperature just enough to prevent the condensation. You can get corrugated foam filler pieces that are designed to fill these gaps, which might be a better idea.

Do you heat the building at all? Some low level background heating will certainly be beneficial.

 

[The_Doctor]

Thanks for your reply Deluks,

The walls are made up of single solid block, and i intend to use a smal calor gas portable heater in there if im ever working - dont know what, if any, difference that'll have on the situation.

The condensation in the garage today wasnt as far spread as yesterday - but it isnt as cold outside!

Im going to seal the joints and gaps today - will post the results when im done.

Thanks again.