Running solo 15ft panels on an open section of roof with no protrusions or obstacles.
Standing seam metal roof installation.
When installing a standing seam it is strongly recommended that all asphalt shingles are removed before the installation in order to prevent avoid the telegraphing effect where horizontally installed shingles punch through the vertical sheet metal roofing panels causing unsightly dents that cannot be fixed removed.
Standing seam metal roof installation cost the labor for metal roof installation costs 2 to 6 per square foot or 3 400 to 10 200 for the average home.
If you have a complicated design you may pay more.
Without a doubt a standing seam roof is quite difficult and technically challenging system to install especially if you have no prior training or experience installing metal roofing but there is also a simpler to install system called metal shingles which looks much like the conventional shingles except that it is far more durable energy efficient and longer lasting.
This means that the minimum roof slope required for panels is 3 inches of rise per foot.
Air pockets are indeed a great way to further insulate the roof.
This estimate usually includes removal of the existing material but disposal can cost extra.
Provided the roof deck is in good shape installing an appropriate standing seam metal roofing such as batten seam over purlins is a viable way to install a new metal roof over the existing asphalt roof.
This video shows how to install standing seam panels when hemming the eave and rake.