Thanks for the input guys.
Yes spraying on the roof is dangerous but I have a safety harness but nowhere to attach it lol. No I can attach it to my solar panels brackets that are screwed to the rafters.
There are a number of roofs in the area that have been painted many years ago and although not perfect are still in good condition.
wigwam I could use the roller but I’ve always fancied a decent spray gun so this is the perfect opportunity.
The real problem I have, apart from the wife’s objections, mainly on safety concerns, is my lack of knowledge on masonary/tile paints.