You are entering into the dirty waters of silicone, so I’m going to caution you on a few things to look for. We only use CFS, the inventor of the system and from a billion dollar company, but not all is similar in the world of silicone. There are two things to keep an eye on.
First, is it fresh water rated. A lot of silicone goes in tropical roofing and the water that hits those roofs is intended to be potable (to drink). Of course, silicone is not what you want in your drinking water. From the outside, this may only look like a question of ecology, as you are likely not drinking your roof water, but nobody really wants to poison the ground water. Of course, nothing is that simple with me. In order for silicone to fail (end up in the water), the binders have to break down. Fact is, if they break down, they fail and cheap silicone breaks down. None of my competition will pass this testing, because they won’t spend the money on the product, period. Others will not know this, because those manufacturers won’t be bringing this up, but it is a very normal standard, called NSA P-151 and we meet it.
The second thing to look for is if microbial life is supported in the fillers that are used in silicone roofing. As an example, if algae grows on a CFS product, it washes right off. In every other formulation out there it grows into the coating and it cannot be removed. This is not just about looks. It could be said that the reflectivity for the clean roof is better, but that’s not it either. Bottom line is if microbial life can enter and live, so can little stuff like water, which will, in time, break down the surface with freeze/thaw, etc. As you can imagine, the two subjects above are somewhat related. The easy test is simple. Run your finger across the samples. If it feels like chalk, then it is chalk. Silicone, if not drown out by fillers, is slick.
There are a lot of misc. considerations. You will hear all sorts of things about how one company is the only one with pure this, or pure that. There are some “siliconized” product, but, for the most part, we can assume the binders are pure silicone of some quality, but all of these products have the fillers that make the colors and the final product. Nobody offers pure resin for a roof. It won’t work and it would be expensive, beyond all roofing. Of course, there is the “where did my crew go this morning” question. My crew went to a job where we are putting silicone down on a roof. Somebody may sound like an expert, but nobody local will say they are doing silicone this month or this year, let alone this morning, but this is what we do for a living, so we know how to do it exclusive of all others and we do it every day. There are big ‘out of towners’, but will they bring the crew and rigs back when you need a little warranty work? Of course not. They will hire a local whom they hope can figure it out at piece rate.
There is a lot to consider. Did the contractor who introduced you to silicone do a pull test, is there a primer needed, is silicone bonding to the surface. For answers, order a white sheet for your roof online and get some of the best information on roofing you will ever see.
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Thank you for the continued opportunity,