I have a few points where the sheetrock is (already) not level between joints. About 1/16" or so. I will be adding hardy backer board which needs to span this joint.
I want to avoid (obviously) a non-level sub-surface for the hardy backer board and "float out" this section. What material should I use?
Since I am new to doing this, a specific type-of material name would be helpful, though I suppose specific "brand" names are OK as examples. Thanks.