How do I install a metal roof over a shingle roof?

How do you put on a metal roof?

Is it okay to install metal roofing over composite shingles?

is it proper roofing procedure to put a 2 1/2" shingle in middle of a row?

What are the disadvantages of a metal roof?

What can I do to remedy dead air space with metal roofing?

What is involved in installing metal roofing?

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