What is the difference between standard PVC pipe and furniture-grade PVC pipe?

Furniture-grade and standard Schedule 40 and 80 PVC pipe of the same size have the same OD (outside diameter). This allows them to use the same fittings. Furniture-grade PVC has a glossy, highly-pigmented, and weatherable outer cap that is extremely resistant to damage and degradation by sunlight. SCH40 and 80 PVC are not intended to be left out in the sun. These pipes and fittings are designed for use inside buildings to carry water, etc. UV degradation occurs in the PVC directly exposed to UV radiation at extremely shallow penetration depths (frequently less than 0.001"). The effects are color change, a slight increase in tensile strength, a slight increase in modulus of tensile elasticity, and a slight decrease in impact resistance. Furniture-grade PVC pipe and fittings are more impact-resistant and have no printing or stampings on the exposed exterior. Also, the fittings available for furniture-grade pipe allow more flexibility in design.

If you use regular PVC pipe for an outdoor application, we recommend that you paint it. You can use a light-color reflective paint coating to reduce the effects of UV. Typically you would use an acrylic or latex paint chemically compatible with PVC. Compatibility should be confirmed with the paint manufacturer. Oil-based paints are not recommended.