I found a little of this hidden in my inspection today. I could not see any data stamped onto the piping although I am thinking it is polybutylene. Can someone confirm please? Thank you.

Looks like PB pipe from here

If it is PB, it’s not an issue unless you see crimped fittings.


Certainly appears to be PB, but you will normally find the PB2110 stamped on the surface.

David, can you substantiate that statement? I’ve never heard that before. Most would say plastic fittings are MORE of an issue than crimped fittings. I simply say this anytime I see PB (the statement below is actually required by the State of NC whenever we see PB…but I modified it slightly to put in a web link and advising them to call a plumber):

“Polybutylene plastic plumbing supply lines (PB) are installed in the house. Polybutylene has been used in this area for many years, but has had a higher than normal failure rate, and is no longer being widely used. Copper and brass fittings used in later years may have reduced the failure rate. For more information about PB, see http://www.pbpipe.com and other Internet resources and/or rely on the evaluation and advice of a licensed plumbing contractor prior to the close of escrow.”

I would not suggest saying that PB 2110 is acceptable because it does not have crimped fittings.

Our Office recommends that all PB be replaced when found to be present.

The type of fittings used with PB are not the only problem. Chlorine added to public municipal water supplies will cause deterioration of the pipe.

I that a plastic dryer hose in that picture???

Yes it is venting a bathroom vent to the exterior wall above some ceiling tiles in a basement.

I would recommend they change out the dryer hose for safety reasons. Plus I agree you have PB on your hands. I would recommend a replacement.

Since that “plastic hose” is just a duct for a bathroom exhasut fan, not a dryer, it should be ok, no? You might recommend that it be the insulated type if it goes directly to the outside wall.


Metal is required around here…

Ok, I didn’t know that.:slight_smile: I could see it for a dryer vent, but thought that for a bath exhaust fan a plastic type would be adequate.

Mark, do you know what’s required out there on the island?


Yea I missed his post that the hose was venting the bathroom exhaust fan how I don’t know fell asleep I guess or just assumed it was for the dryer lol regardless I always recommend installing metal over plastic for any type of venting especially those with any type of heat source.

Most insurance companies around here are not insuring homes with PB water lines. Replace them. Too many issues either way.


How would the insurance company know if PB 2110 is installed? Do you tell your client to replace PB 2110, even it has been in the house since 1994, with no problems?

If you know about it, they should know about it, too, IMO. Around here, it is not the deal-killer it seems to be elsewhere. Plumbers are still using it! Watch for the plastic elbows which can snap apart. :mad:

Plastic vent hose is cheap and problematic in all applications. The picture is from a bath vent, hose about 10’ long. Lint, dust, + warm moist air = mold. :mad:

John Kogel


Nice find John. Do you know if a plastic vent hose is more prone to mold than a dryer type flexible metal one? I suppose other factors contribute, such as the length of the hose, size of the fan and if it travels through heated/unheated space and if it’s insulated or not…



PS. I used to live out near there at Pearson College (Metchosin). Ever been out that way?

I agree with John, it is not as problematic in Western Canada for some reason. Although, I don’t see plumbers using it anymore, its mostly pex. Why is this? It is the same product from the same manufacturers in the USA. Is polybutylene safer to use in Canada? I read an article from a CAHPI perspective and it states that it is not a significant issue and less than 2% leaks.