What asphalt roofs can be re-roofed?

all asphalt roofs can be re-reroofed based on your states laws

basically if you have only one layer of roof on your existing roof you are legal to replace it with a "go over" roof, any more then 2 layers is considered bad due to weight, and can be illegal in some areas/states.

this is Avery good way to save alot of money on a new roof as there is no riping labor or waste fees!!!!

you can save money by roofing over an existing layer of rooing, but make sure they check for any rotten wood that may need to be replaced. Otherwise you'll be spending more money for a roofer to come out and repair both layers.

Just a professional opinion:is always better to remove the old roof and start over.