12/29/2025
Polybutylene can be bad. Plastic fittings are WORSE.
Most people know to look out for grey Polybutylene (PB) pipes. These systems used either copper or plastic fittings.
The plastic fittings (like the one I'm pointing to here) are notorious for cracking and failing from the inside out. They are so prone to failure that I almost never see them anymore, even though I see PB piping with metal fittings on many 80s and 90s homes.
I found two of these rare plastic fittings at this inspection in a very difficult-to-access area of the crawlspace. Unsurprisingly, both were leaking.
This is why experience matters, to find what others miss.