Hi,
I'm in the process of installing a kitchen in my house that was heavily modified in the 80s and have discovered a network of PB water piping since lifting up the floorboards.

The advice from various tradesmen has been mixed as to whether it's worth replacing it - ranging from "it's the next leaky homes scandal waiting to happen" to "if it's been all right this long then leave it alone"

We did have a burst pipe last year after the street water main was replaced, no doubt increasing the water pressure considerably, although the pipe looked as though it had been squashed at some point.

As part of the kitchen renovation we're probably going to switch to a mains pressure hot water system from the low pressure we have right now which makes me a little nervous. I have been quoted approx $600 to replace what can be accessed right now and I'll have to get the bathrooms and laundry done at another stage.

So, is it a "time bomb" waiting to go off under my new hard-wood floor or is it $600 I don't really need to spend?

Thanks in advance

Rich

Linkback: https://www.plumbers.nz/ask-plumbers-public/2/polybutylene-to-replace-or-not/319/

I would opt with replacement too,why take the risk with a brand new kitchen at stake. Even more so if the pipework is not able to be easily accessed later on it will cost even more if something goes wrong. The jump from low pressure to mains pressure could also very easily cause a fitting to begin to weep water,more so if the existing pipe and fittings are decades old.I've seen it many many times after removing a low pressure water heater and installing a instantaneous mains pressure water heater(i.e infinity,bosch highflow). Wouldnt be a bad idea to also inspect the pipe that conveys the waste water from the kitchen to the drainage system for whatever system you currently have. This can be quite important to people that are having a new kitchen installed with a waste disposal unit. I've seen a few new kitchen wastepipes joined onto half blocked 40year old galv wastepipes and with the addition of the waste disposal unit they can become slow draining or block very easily. Im in my eighth year of plumbing gas and drainage,hope this knowledge i've picked up over the years helps you make an informed descision. 

Cheers,  Rod