I am in the process of replacing my garage trim with PVC. Before I get that done, I was trying to remove broken/loose asphalt that had eroded throughout the years. I am looking at about 2-3" wide and 4" deep at the "missing" asphalt. I am planning to patch the area with Aquaphalt 6.0, as I heard great things about it.

Should I fill all 4" with asphalt? Or is there any specific sand/gravel/dirt I should be using as a base layer?

Any help would be appreciated. THANK YOU!

 

I have never heard of that brand but any cold patch works best when it's "contained" in a void like what you have, vs trying to fill a low spot where the edges are laying on the surface.

Fill it and pack it!