Are Polybutylene Pipes bad? For many years they have been used in many homes with no issues. The issue overall is that they tend to leak at the joints over time. And when they leak, they can leak and create quite a bit of damage. I have owned 2 homes with these pipes and i just replaced all of them in one of my townhomes after 3 small leaks. The cost was about $3300 and hopefully no more leaks. The reason they were so popular in the late 80’s was that they are so easy to install with no soldering and they are so pliable. Make sure that if you purchase a home with these pipes that you alert your insurance company to see what type of coverage they provide. There is also a home warranty that does cover up to $1000 in repairs for this leak (make sure your home warranty provides this coverage). The $1000 may not be enough coverage but it does provide some. Full disclosure – i am not a plumber, just a real estate broker who has sold many homes with this plumbing. As always, please consult a licensed plumber for more questions/opinions.