Insulation strategy for staple-up radiant zone – GreenBuildingAdvisor

I live in central Vermont and have a staple-up hydronic radiant floor (Onix) under a tiled living space (10’x18′). The basement below should be treated as unconditioned, but it has easy working conditions. Rodents have compromised the foil-faced R19 fiberglass insulation currently installed, and I’m looking to bolster the R-value and prevent further issues. House wrap is currently stapled across most of the joists. The 2×10 joists measure 9″ in depth, and the exterior sill has been spray foamed. This is a DIY project.

My tentative plan, from top to bottom under the tubing, is to install:

1. Radiant barrier (solid or perforated) 3.5 in from the subfloor.

2. Rockwool comfort batts (R23, 5.5 in) – wish it came faced!

3. Rigid foam across the joists (not sure what type is appropriate or how thick yet)

My rationale, not necessarily correct, and why I’m reaching out, for the install above:

Layer 1: I was considering AtticFoil.com products, but I’m open to any recommendations. I’m also unsure how I’ll consistently staple the foil across the joist bays. Does anyone have any best practices or tips? Should I buy perforated or solid foil?

Layer 2: I like the idea of rockwool to deter future rodent problems, the easier friction-fit installation, and less cutting between the 16″ on-center joists. I was thinking about R28, 7.25 in batts, but Onix recommends 2-4 in air gap between the subfloor and foil face. I have 1.75 in with 7.25 in wool batts. Do you think I should even be concerned? The cost difference between R28 and R23 is negligible.

Layer 3: If I go with 5.5 in wool batts, I could increase the foam board thickness to improve the R-value and reduce thermal bridging from the joists. I’m perplexed by the variety of foam board, whether it’s foil-faced or not. What should I get? And if I need foil-faced here, which direction should it face?

Appreciate the forum for this and past projects. Thanks so much!!