Whites are not going to do it as it is too hot for them. Pay more? White boys want easy work here. I roofed and unloaded box cars in the hot summer in VA at 16 years old. Also worked 9 on and 3 off on a scallop boat at 17.
There is no job in the entire world that does not have a price point for indigenous labor. None. It is an economic fact. If I advertized for roofers at 50/hr I would get roofers. If I advertized for roofers at 8/hr I would get no roofers. So it is incumbent on the contractor to find the correct price point which is somewhere between 8 and 50.