Steel roof leaking

[PILOON]

Still think condensation is probably the culprit.
For sure if the attachment screws are on top of the ridges it is condensation.
On the flats could be infiltration.
If screwed on the ridges then a vapor barrier could be the solution.

If the pitch is 3-4/12 and on the top of ridges I doubt it is infiltration but more like condensation or 'sweating', keeping warm moist air away from the cold metal roof is the solution.

 

[Rustyiron]

It can be hard to identify the leaky panel seam when your on the roof, but you just need to unscrew it and calk or butyl tape and screw it back down. I like the tape myself. This can happen when the "guy's" adjust a panel to end up with an even reveal at the end wall. You can only adjust each panel slightly before you get troubles. I have seen perfect seems leak in super crazy down pour also. (not an actual meteorological term)

 

[mcgoo]

It can be hard to identify the leaky panel seam when your on the roof, but you just need to unscrew it and calk or butyl tape and screw it back down. I like the tape myself. This can happen when the "guy's" adjust a panel to end up with an even reveal at the end wall. You can only adjust each panel slightly before you get troubles. I have seen perfect seems leak in super crazy down pour also. (not an actual meteorological term)

Because of my mezzanine in the long slope side of the shop I can get very close to the underside of the roof to find leaks. Found 3 so far. This tape is very interesting!

 

[Oldpath05]

How old is your building/roof?
In one of your pictures, it appears that the steel on your roof is in poor condition.
Before being concerned about condensation, and/or insulation, it would be best to determine the condition of the steel on your roof.

I was thinking the same thing, the metal roof looks to be a 100 years old to me, and why so many screws. I would only consider putting metal roofing on purlins on a woodshed or lean-to

This metal roofing was put on a little over 3 years ago, on top a boarded roof, instead of tar paper I used synthetic underlayment because I got a deal on it, screwed down every 2'-ish>>>>

 

[mcgoo]

I was thinking the same thing, the metal roof looks to be a 100 years old to me, and why so many screws. I would only consider putting metal roofing on purlins on a woodshed or lean-to

This metal roofing was put on a little over 3 years ago, on top a boarded roof, instead of tar paper I used synthetic underlayment because I got a deal on it, screwed down every 2'-ish>>>>

View attachment 499575

The building was built in 1984 so it makes the roof 33 years old. I purchase a property three years ago. The tin is actually in pretty good shape it just looks worse because it was originally coated black and now the black is peeling off. It's still galvanized and not rusting out whatsoever. I would agree with you about the method used. If I had my way I would have done it with sheathing. Not sure why so may screws we used....

 

[Oldpath05]

" The tin is actually in pretty good shape it just looks worse because it was originally coated black and now the black is peeling off." <<That explains it, an optical illusion. Sounds like a costly problem, can't wait to here the solution, good luck........

 

[hslogger]

Screw down roofs are gonna leak sooner or later. you can pull the screws out and put in over size ones. You can do that and caulk em.
I have pitched roof that is not very steep on my barn that was put up in the eighties. Screwed in. We are gonna pull it off, sheath it with plywood and put down new metal that is snap down hidden screws. I have that on a couple newer buildings and wish to heck the barn was done that way to begin with.

 

[redman135]

From the age you have quoted , have you removed a sample of screws to check the condition of the weather-seal washer? When my parents bought their retirement place the garage leaked. The cause was a perished weather seal washer on the screws. A full set of new screws (and seals) later and problem fixed. The garage was a similar age.
Some posters have commented about the number of screws, is the building in a "high wind area"?

 

[RNeumann]

To me a lot of folks are missing the main issue. The uninsulated shop is heated and contains a fireplace showroom. It's an ideal situation for ice dams and good old wicking. Roofs, in general, rely on two layers- ice and water shield and or underlayment and a top/main layer which is metal in this case.
Trying to get around that fact is asking for ongoing issues.

 

[sailfast]

To me a lot of folks are missing the main issue. The uninsulated shop is heated and contains a fireplace showroom. It's an ideal situation for ice dams and good old wicking. Roofs, in general, rely on two layers- ice and water shield and or underlayment and a top/main layer which is metal in this case.
Trying to get around that fact is asking for ongoing issues.

Exactly!
You definitely have a condensation problem though you are focusing on the apparent leaks.
The leaks have started due to corrosion via condensation.
The roof will be VERY slippery to work on... Hire a professional to either replace entirely or to spray a coating on. As well, spray 1.5 inches of closed cell foam on the interior side.
I run a company that does this, you need to look at the entire building envelope rather than just focusing on the apparent leaks.

From the age you have quoted , have you removed a sample of screws to check the condition of the weather-seal washer? When my parents bought their retirement place the garage leaked. The cause was a perished weather seal washer on the screws. A full set of new screws (and seals) later and problem fixed. The garage was a similar age.
Some posters have commented about the number of screws, is the building in a "high wind area"?