I made a cheap grid from 1x4 furring strips, dropped 2 inch foil faced rigid foam then rolled out 48” pole building insulation on top. Keeps my metal building car shop nice
Foam Board Insulation - Metal Building Insulation | Service Partners
7✓ Scenarios: How to Install Foil Insulation the Right Way [Date] | Q1 2024 | Updated
RMAX Pro Select R-Matte Plus-3, 0.5 in. x 48 in. x 8 ft. R-3.2 ISO Rigid Foam Board Insulation 637902 - The Home Depot
ETW: Foundation - 2" XPS, 2" Foil-Faced Polyisocyanurate | buildingscience.com
Buy Hunter Xci Foil | Hunter Panel
US Energy Products Reflective Aluminum Foil Foam Insulation: (2ft x 25ft) Industrial Grade Foam Core Radiant Barrier: Soudnproofing, Automotive Insulation, Weatherproofing, Roofs Floors, Windows, ETC - Amazon.com
R-Tech 1 in. x 48 in. x 8 ft. R-3.85 Insulating Sheathing 320821 - The Home Depot