If you have no access it s hard for me to tell you to go to extremes to find a way.
Do you need to ground antenna in attic.
But if you have access to a ground connection that can serve the attic splitter it makes sense to use it.
The nec requires that the antenna mast be grounded directly.
If you ve taken the time to insulate lay flooring or even decorate your attic however you may want something that s a little less of an eyesore.
For all practical purposes an attic antenna is considered and indoor antenna and does not require any special grounding.
There is no requirement to ground an indoor or attic antenna.
If you find the attic install unsatisfactory and you move the antenna outside then you definitely do need it.
However the connection of your antenna coax to various ac operated equipment in this case your converter box or tv introduces the potential of electric shock.
In the case of an attic installation your tv antenna will be sheltered from the environment so there s no need to ground it for that reason.
Typically the house wiring and gutters represent a much lower impedance path to ground for lightning than the floating attic antenna.
Below is an image taken form the nec code book that shows how to properly ground a tv antenna.
Keep your grounding parts however.
Some attics are dark unwelcoming places used only for extra storage and in those cases nearly any antenna will get the job done.