Wavy PEX B hot water pipe

[Jonlybonly]

Maybe I did something wrong when installing my Pex B pipes, but the hot water side seems to have some wild waves in it after a month. The pipes were straight 10 foot runs I purchased from Home Depot, all were secured with c clips nailed into the framing, same as the previous PB was.

Is this normal? Something to worry about? There are no kinks, but a general waving back and forth.

 

[Twowaxhack]

When pipes get hot they expand.

 

[Jonlybonly]

When pipes get hot they expand.

Yes, fully understood. But is this a concern? Should I take out some slack?

 

[Twowaxhack]

Post pictures of it

 

[Jonlybonly]

Post pictures of it

Crazy, it was much wavier before. My son was in the shower, so all that hot water must have been passing through the pipe. I guess this is normal?

 

[Twowaxhack]

it’s normal. Looks good and you agreed before someone deleted our posts.

Have a good day.

 

[CT-18]

I think pex B says supports every 30" or something in that area. If it is moving to much for your comfort you can always add more J hooks

 

[Jonlybonly]

Thanks everyone, I’m very new to Pex and definitely don’t want another flood.

 

[quinlanj98]

I did some calculations for a long PEX run in my basement and was surprised by the results. PEX expands at a rate of about 0.01% per degree F of temperature change. Assuming a wintertime basement temp of 55F and a hot water temp of around 120F, the max. resulting change of 65F could produce a pipe length increase of 0.01% X 65F = .65%. So a 10 ft run could change in length by nearly an inch. To accommodate that extra length, the pipe would need to bow out from a straight line by roughly 6 inches! (assuming you only clamp it at either end and that I didn’t screw up the math).

 

[Jonlybonly]

I did some calculations for a long PEX run in my basement and was surprised by the results. PEX expands at a rate of about 0.01% per degree F of temperature change. Assuming a wintertime basement temp of 55F and a hot water temp of around 120F, the max. resulting change of 65F could produce a pipe length increase of 0.01% X 65F = .65%. So a 10 ft run could change in length by nearly an inch. To accommodate that extra length, the pipe would need to bow out from a straight line by roughly 6 inches! (assuming you only clamp it at either end and that I didn’t screw up the math).

That’s interesting. I clamped it probably every 30 or so inches, which I thought was appropriate. I’m concerned that additional clamping will be more of a problem.