I have owned my condo for 18 months. I live on the 3rd of 5 floors. The building is 50 years old. I have recently remodeled my kitchen and have all new plumbing pipes. I have had many back ups in my kitchen sink prior to and after the remodel. Most recently it happened 3 weeks after I left the condo. I have someone check the condo every couple days and for 3 weeks everything was fine. Then the housewatcher noticed another back up. The plumber sent in by the condo association said the back up was caused by my use and was in a pipe in the condo. Since the sink had not been used for 3 weeks I told them it had to be a backup in the verticle drain pipe serving the kitchens above and below me. I have requested a scope in the verticle pipe. They refused to do it. What do you think?

If you are not using the drains and a backup is seen then it must be supplied by units above you. The clog is between you and the floors below. Common areas like interior pipes are the responsibility of the HOA but you must carefully read your covenants to get all of the details. You can't prescibe how they fix it but you can demand that it be fixed. Rodding down from your location is warranted.