I don’t have a barn, but I did a TON of research on painting my house because I decided I wanted to do the best job and have it last 20 years, not 10.
Yes, go with Sherwin Williams, or one of the other paint only brands. Do NOT do a Home Depot/Lowe’s brand. I did a LOT of research into Duration and Emerald. The ONLY reason it’s so much better is you don’t need to prime it first–it’s a primer/paint combo. Normally it’s $70 a gallon (Emerald is $90.) Now, there is NO way I am paying $70 for a primer. They WILL try to sell you on Duration or Emerald, but should admit what I just told you.
I had a professional painter do the house and he agreed. Prime the house with a really good oil primer if you can find one (it’s illegal in CA) which is MUCH cheaper than using your paint as a primer, and then paint with SuperPaint, which is the same paint at $50 a gallon. The one in between SuperPaint and Emerald is about $60 a gallon and is good if you have an issue with possible rain (it wasn’t for me.)
AND, they do have the 40% off sale about every three months. I think they had one about a month ago, so it’s coming up soon.
So, I would prime with oil primer and buy SuperPaint at 40% off and get it at $30 a gallon instead of $50. I have a small, two bedroom house and paid $650 for paint. If I hadn’t gotten it on sale, it would have been $1,000. Duration or Emerald would have doubled that.
I’m not a painter, but I spent MONTHS perusing the contracter boards, reading everything I could, and checking out ALL of the information.
And, if you’re going my route and would rather do it right once instead of having to do it again sooner, make sure you prep really well. I don’t know what your weather situation is there, but I would make sure you have a long dry run to pressure wash really well and dry really well before you prime and paint. My house looks REALLY good and I don’t expect to paint it again before I die.
Oh man. You added that as I was typing. Did you buy it already? I hope not.