Specify UV Resistant Materials

Some materials are naturally UV-resistant, while others require the addition of UV inhibitors in the make-up of the material. For example, concrete or clay tile roofing and Portland cement stucco or brick siding are naturally resistant to UV radiation and are also resistant to temperature effects compared to other exterior building materials. On the other hand, plastics are prone to “dry rot” (embrittlement from excessive UV exposure) unless UV inhibitors are provided. Plastics are also prone to significant expansion and contraction from temperature swings. Vinyl siding is a perfect example of how this technology has advanced. Years ago vinyl siding was prone to UV degradation, but is now highly resistant to both cracking and fading.

Be sure that UV inhibitors are used in materials that require protection. Many low budget components, such as some plastic gable end vents, may also lack UV resistance. All other factors being equal, choose the material with the best UV resistance if exposure to the sun is a concern.