If you would like to reply to this thread, please log in. If you do not have an Ask the Experts forum user account, create one here.
If you would like to reply to this thread, please log in. If you do not have an Ask the Experts forum user account, create one here.
We live on a lake and the reflection from some of the metal roofs are very unpleasant and at times the glare does not allow neighbors to enjoy their patio and backyards. Is there a specific color, finish, that is best for a location on a lake. Most of the houses that are unappealing are ones with light color roofs, grey, silver, bluish. The houses in the development that have dark roofs give off no glare but not of these are on the lake. The ARC (Architectural Review Committee) is looking to put something in to make sure that no more homes on the lake give off the glare as people are already talking about home values going down due to the glare and problems. Can you recommend what types of roof would be the best, reflectivity rate, etc. ? Looking to keep all homeowners happy.
1/7/2021
Thanks so much. My experience is that, after going through a couple of seasons, any gloss and sheen does significantly diminish. (Think of not washing your car for a year or so.) Typically, on a new metal roof, the worst case will be a situation where the sun is behind the building ... that causes sheen on the side you are facing. That said, most manufacturers offer low gloss coatings and some also offer multi-hued colors that seem to help with this as well. Textured finishes can also be helpful, as can stone coatings which are available on steel shingles. Usually, too, the more texture the product itself is, the better it is at not showing gloss and sheen.
Isaiah Industries, Inc.
1/8/2021
Hello, Wendie. I have been at Lake Tahoe since the 1970s and reflective surfaces have always been of great concern here so I understand yours. Even the ceramic chips on shingles have a glittery reflection at the right angle.
Reflectance can be measured with a “glossmeter” and glosses are ranked on a scale from 1 to 100, 100 being the glossiest. Thirty years ago I introduced “Low-Gloss” paint finishes to our standing seam roofing customers. While it had been available previously we had never seen it used in roofing metals before. There are some roofing manufacturers that still offer low-gloss paint finishes. Look for ones with specular gloss rating well under 20 per ASTM D523. You will still get considerable reflectance with a sub-20 gloss rating when the sun is just right. Many standard roofing paint finishes fall in the shiny 55-75 range and are actually preferred for some commercial installations such as car dealerships and restaurants.
Copper roofing, after it patinates, achieves a very flat finish and will last a lifetime. For a more affordable option and an even flatter, virtually non-reflective roofing surface you might consider a “weathering steel” (aka Cor-Ten) metal roof. It oxidizes over time and eventually achieves a very stable, dark purple/brown velvety surface. While some naysayers voice concerns about this material as a roofing product it has been in use in the heavy snows around Lake Tahoe for more that 40 years and the roofs are still in service. The flattest surface would probably be a corrugated roof but they are generally a poor choice due to their exposed fasteners. The resurgence of Cor-Ten steel tiles with installations that are still in service here dating back to the early 1970s will soon be available again.
Our area is so strict on reflectance that Schott (museum grade) glass is required for glass deck railings within view of the lake. At one time Cal-Trans, our state’s highway maintenance operation, used galvanized steel for metal beam guardrails along Tahoe’s highway. The area’s architectural authority forced Cal-Trans to replace them with Cor-Ten steel. You will also see it everywhere in bridges, power poles, sculptures, and cladding buildings.
Cor-Ten Sierra Steeltiles
3/6/2021