I have a pole barn in mid-michigan (41 feet long X 24 feet wide) that is long overdue for a re-roof. The current asphalt shingles are long worn out, and water has been leaking thru for a while. The sheathing is not totally shot, but some peices would definately need to be replaced. The thought of this tear-off etc. pains me. My question is this, is it acceptable to roofover it with steel roofing and avoid doing much tear off? I was thinking it would be nice to run perlins right over the roof as is, and then put the steel on the perlins as normal. I have professional experience, so the installation is not my concern, just any problems that might come from leaving the old sub-roof and shingles etc. Would love advice, thanks
I re-roofed my house with a steel roof over the existing ashpalt on purlins. My old roof was still in fair condition. What I would suggest is that you lay 30# felt paper over the existing roof before the purlins. You can get some condensation on the bottom side of the metal and this 30# paper would make it a little safer.