The good news is that there are many different solutions in terms of installing metal roofing panels including tin aluminum and steel.
How to install steel roofing on a house.
In many cases it makes sense to remove an old or dilapidated roof and install a metal roof that is better able to withstand the elements.
If you want to install steel over asphalt your best choice is to use a steel shingle system like the one shown instead of the more common and more expensive standing seam steel.
To watch the entire series from the beginning click here.
Be sure the larger edge is laid so that the small edge of the next panel will overlap it.
Next use 1 inch nails to secure some metal edging to the perimeter of the roof.
In a standing seam roof long single panels run vertically all the way from the eave to the ridge.
Then cover the entire roof with a layer of insulation and secure it with a staple gun.
Align the first metal roofing panel so that it overlaps the edging by 1 2 to 3 4 of an inch and is square to the roof line.
Install the roofing screws vertically along each rib in the panel.