Lone Star Spirit

SPC flooring is a modern and durable option that combines the best of both worlds: natural wood's beauty and vinyl's practicality. What sets stone polymer composite vinyl flooring apart from other flooring is the nature of its core. It's composed of multiple layers, including a rigid core made of stone polymer composite (SPC), which gives it incredible strength and stability. This is what provides the rigidity and stability for the plank, different from the flexibility of other vinyl flooring. Because SPC tends to be thicker than other vinyl floorings, it adds more support underfoot. This also makes it look even more similar to natural hardwood flooring, including having the same denser feel and ability to retain heat and does better in areas with direct sunlight. Lastly, a pre-attached underpad provides higher sound insulation and cushioning. You may also hear that SPC is made of Stone Polymer Composite.

A refrigerator sitting on top of SPC flooring will not void the warranty. It is recommended that a protective surface by used when moving the refrigerator both in and out of this space. A thin underlayment board or protective shield prevents the wheels from damaging the surface or tongues in the locking system.

Yes, you can, but nothing thicker than 1mm products like Floor Muffler: https://floormuffler.com/products/

Look at "For use under Luxury Vinyl & Rigid Core."