Thanks for your comment about apparently accelerated UV degradation of roof-paint products in New Zealand.
Without having access to comparative climate data for Auckland and the test site in Florida, I'm at a loss to explain the much more rapid degradation in Auckland. As I mentioned in my post (from three years ago now!) , climate factors other than UV exposure may be at play. These possibilities include humidity, rainfall, diurnal and seasonal range of temperature, sunshine hours, air pollution, and others I'm sure. If you provide the name of the test site in Florida, I could try to obtain climate data to look into this further. Or perhaps you can provide data from both test sites? But I can't promise the analysis for nothing. There could be quite a bit of work involved.
I must say that I'm rather surprised the roof product you mentioned lasts only 3 years in Florida. I imagine there must be few disgruntled clients there. And even more in Auckland if it lasts only 19 months before showing signs of damage. If the damage were truly due to UV exposure, the graph in my post ( - https://uv.substack.com/p/uv-degradation) shows the product wouldn't last a year in northern Australia! Being at similar latitudes, Auckland and Melbourne have similar annual UV doses. In that case, you would be rightfully inundated with complaints within a year of installing the product. There plenty of places in northern Australia with higher UV doses than Darwin, which is rather cloudy in summer.
I wonder if your product (or one of its constituents) is being produced in strict accordance with the specified recipe?
Can you give me more details about the early failure of seals? (e.g., how prevalent, where, when, etc...). It must be a manufacturing issue, or a combination of environmental factors: like a combination of high UV along with high humidity or temperature. As the plot on the blog shows, the UV alone wouldn't do it.
It's interesting that you raise this issue, as my father started the company (RX Plastics) that may have made them.
I agree with Mike Molyneux. I worked for Rohm & Haas (now a part of Dow) who ran the world's largest outdoor paint exposure testing program. I used to run a site in Otahuhu. Paints chalked a lot faster in Otahuhu compared to Florida. A styrene-acrylic based roof paint that lasted over 3 years S45° in Florida, chalked significantly in Otahuhu at N45° after 19 months. We saw this in many exposure studies.
Sunlight degrades and cracks flexible rubber seals on large storage tanks in New Zealand within 12 years. These seals last up to 20 years in most other countries.
Hi Greg
Thanks for your comment about apparently accelerated UV degradation of roof-paint products in New Zealand.
Without having access to comparative climate data for Auckland and the test site in Florida, I'm at a loss to explain the much more rapid degradation in Auckland. As I mentioned in my post (from three years ago now!) , climate factors other than UV exposure may be at play. These possibilities include humidity, rainfall, diurnal and seasonal range of temperature, sunshine hours, air pollution, and others I'm sure. If you provide the name of the test site in Florida, I could try to obtain climate data to look into this further. Or perhaps you can provide data from both test sites? But I can't promise the analysis for nothing. There could be quite a bit of work involved.
I must say that I'm rather surprised the roof product you mentioned lasts only 3 years in Florida. I imagine there must be few disgruntled clients there. And even more in Auckland if it lasts only 19 months before showing signs of damage. If the damage were truly due to UV exposure, the graph in my post ( - https://uv.substack.com/p/uv-degradation) shows the product wouldn't last a year in northern Australia! Being at similar latitudes, Auckland and Melbourne have similar annual UV doses. In that case, you would be rightfully inundated with complaints within a year of installing the product. There plenty of places in northern Australia with higher UV doses than Darwin, which is rather cloudy in summer.
I wonder if your product (or one of its constituents) is being produced in strict accordance with the specified recipe?
Looking forward to your response.
Richard
Can you give me more details about the early failure of seals? (e.g., how prevalent, where, when, etc...). It must be a manufacturing issue, or a combination of environmental factors: like a combination of high UV along with high humidity or temperature. As the plot on the blog shows, the UV alone wouldn't do it.
It's interesting that you raise this issue, as my father started the company (RX Plastics) that may have made them.
I agree with Mike Molyneux. I worked for Rohm & Haas (now a part of Dow) who ran the world's largest outdoor paint exposure testing program. I used to run a site in Otahuhu. Paints chalked a lot faster in Otahuhu compared to Florida. A styrene-acrylic based roof paint that lasted over 3 years S45° in Florida, chalked significantly in Otahuhu at N45° after 19 months. We saw this in many exposure studies.
Sunlight degrades and cracks flexible rubber seals on large storage tanks in New Zealand within 12 years. These seals last up to 20 years in most other countries.