Need a knowledgeable Chicago plumber referral

[Rachel Imhof]

I live in downtown Chicago and have my neighbor directly above me who has had two different plumbers come out and advise him supposedly that his P trap under his tub needs to be repaired as it is leaking into a unit below. They convinced him that the only way to repair it is to come through my ceiling in my bathroom which is drywall then concrete. I told him that there has to be a better approach to fix this issue. How can breaking out concrete above your head be safe including a structural safety to the building. So I'm looking for a referral for him on a plumber who is very familiar working downtown inside condo buildings. All of my plumbers are good with SFH's and looking toward this great network for a great plumber with great experience and knowledge. Thanks and have a great Labor day weekend!!