Would it hurt anything having the antenna in the attic? As in hurt i mean would i lose any signal strength being in the attic?
It really depends.
Some home insulation uses a foil vapor barrier, this can block signals.
Some roofing materials may be metal, that can block signals.
Wiring and copper/metal plumbing in the attic can create issues.
Metal ventilation ducts can be a problem.
Really depends on the construction.
I've got a location at work where I needed to mount a GPS timing antenna. I didn't have any room on the existing masts, so I was able to mount it to some rafters. Since it was a composite roof with plywood sheathing, it wasn't an issue. The GPS signal is just fine under the roof.
For scanner listening/transmitting, you really want the antenna up high and in the clear if at all possible. I do understand that isn't always possible. If your home construction is right, mounting in the attic will work.