We are using the Firestone TPO roofing fabric (PVC-free and without harmful fire retardants) in a new Mistral Yurt. It is the first time we are using this material, and while we can only sell it in states without strict fire retardant laws (not in New York, New Jersey, Mass, Michigan, California, Canada), it is such a great fabric we think that it is worth the hassles. It is super thick and durable, comes at a good price because it is made in great volume, comes in widths up to 12′, and is made to stay clean and reflective. Seams are heat sealed (this is good, waterproof seams and no solvent glues). You get the choice of white or tan (OK, we know that this is an issue), but the good thing is that it is healthy to live in and work with.