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

Standard Schedule 40 and 80 PVC Pipe and Furniture-Grade Pipe of the same size have the same OD (outside diameter), allowing them to use the same fittings. However, furniture-grade PVC has a glossy, highly pigmented, and weatherable outer cap that is extremely resistant to damage and degradation by sunlight. In contrast, 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"). Possible effects include color change, slightly increased tensile strength and modulus of tensile elasticity, and somewhat decreased impact resistance. Furniture-grade PVC pipe and fittings are more impact-resistant and have no printing or stampings on the exposed exterior. In addition, the fittings available for furniture-grade pipe allow for 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, an acrylic or latex paint chemically compatible with PVC can be used, with compatibility to be confirmed with the paint manufacturer. Oil-based paints are not recommended.