Beware of the use of silicone for everything on an exterior surface. Use only where you do not need to paint, even in the future as paint will not stick to most silicones.
I have found that a polyeurathane sealant adhesive to be a better option and can be painted over. I have had places like zincalume gutters and flashing where silicones have been used and as a result the silicones have to be cut, scraped and cleaned of all residue before any paint can be applied. Also on caravans, people persist on using silicones and then when you have to touch up an area, you have to rid the area of all the residue. It would have been better to have used these sealant adhesives ,which are easier to use and clean the areas as you go, and then save your hours of cleaning off the silicones.
