Corrugated Metal Roof Damage
Most corrugated metal roof damage
will be caused from moisture and in this case, the builder ran the
corrugated metal roofing in the wrong direction. The grooves in the
metal roofing should have ran parallel to the roof rafters.
I've never seen a metal roof built like this before, but there's a first time for everything. As you can see, most of the water damage is accumulating where the metal roofing laps on to the next piece.
If the roof slope was steeper, the small lap of metal roofing, might actually be enough and they wouldn't have never had a problem with it. Lower sloped roofs, need to make make sure that the metal laps are at least 6 to 12 inches and it wouldn't be a bad idea, to use some caulking or plastic roof cement at these joints.
Home Repair Tip: You will need to remove the corrugated metal roofing and run it in the right direction.
If you look closely, the roof rafter that is closest to the top of the picture, has what looks like to be a 2 foot piece of 2 x 4, nailed onto a broken roof rafter. There's a good chance that there was either a heavy rain or snow loaded upon this section of the roof framing and the weight of this load, broke the roof rafter.
The 2 x 4 roof rafters are undersized anyway, not only is the metal roof running in the wrong direction, these roof rafters should have been at least 2 x 6. But probably should have been 2 x 8.
The biggest problem in a situation like this, would be, during a heavy rain or a period where snow was to load up on top of the metal roofing, this section of the building could actually collapse and hurt someone.