There are so many roofing companies in Dublin and Ireland as a whole. You have your roofing contractors that are nationwide and could have upwards of 500 roofers employed. You also have your local roofers that service specific locations in Dublin and all other counties. It would be difficult to say who are the best roofing companies. But what you can do is make that decision for yourself by doing your research on a roofing company you are considering in hiring. Check their social media, Google reviews and other websites.