Armacell AP Self-Adhesive Sheet Insulation vs Owens Corning FOAMULAR 150 XPS Board

For most insulation jobs, the Owens Corning FOAMULAR 150 is the stronger board: R5 per inch, closed-cell XPS that shrugs off moisture, and 15 psi compressive strength for below-grade and sheathing use. The Armacell AP sheet is a flexible nitrile/PVC elastomer at R4.2 for a 1-inch sheet, and its self-adhesive backing makes it the quicker pick for wrapping ducts, pipes and irregular surfaces indoors. Reviewers of rigid XPS boards consistently rate them for durability and cut-and-fit ease; foam rubber sheets are valued for conforming to curves and sticking in place without fasteners.

• Choose the Armacell AP sheet if you are insulating ducts, pipes or curved and irregular surfaces indoors and want a peel-and-stick sheet that conforms and stays put.
• Choose the Owens Corning FOAMULAR 150 if you need rigid board for walls, foundations, sheathing or crawl spaces where moisture resistance and compressive strength matter.