Shingle roof

Hello, not having to do any roofs until now is there any issues in putting a shingle roof over an existing shingle roof on a 16 x 80 sw or should we do a tear off on the original roof. The home is a 1991 model. The park is located in N.W Indiana. Thanks for the help, Rich

I would shingle right over the top, unless you have rotted wood.

Thanks Jim for the quick response! Rich