Copper water supply through flexing floor joists

[OnlyinCali]

I'm pretty sure I'm overthinking this but I'll ask anyways.

I'm running new 1/2" and 3/4" copper water supply lines through (mildly) undersized floor joists. The joists are 2x10s over a 20ft span and have a little more flex to them than I like. The copper has to be run perpendicular for 10 ft or so, through roughly 5-6 joists.
Is a little bit of flex/vibration an issue since I will be running about 10' of copper through them? I'm assuming every house built prior to 1980 is this way and I'm just overthinking it, but I figured I'd check.

I was planning on boring 1" or 1 1/4" holes for my copper and then filling in the dead space with expanding foam to give a little cushion/flex. Is there a proper way to do this to avoid joint failures after 10 years of kids running across the undersized joists and therefore vibrating/slightly flexing my copper?

 

[Dj2]

What is your joist spacing?
Are your joists Doug Fir?

 

[Sponsor]

 

[Reach4]

Is this pipe going to be over a finished ceiling? If not, why not go under the joists?

 

[PorcelainVacation]

If you don't have any, adding x bracing or blocking between the joists will stiffen it up considerably.

 

[Terry]

I drill my copper holes with an 1-3/8" bit. They make nice pipe insulators for that size hole.

EZGlide Tube/Insulator used with a 1-3/8" hole. They come in 1/2", 3/4" and 1" pipe sizing.
IPS 82951 Suspension Clamp
And a pipe clip.

 

[Jadnashua]

If you don't have any, adding x bracing or blocking between the joists will stiffen it up considerably.

Cross bracing helps with POINT loads by sharing things between joists (but a properly installed subflooring, glued and ring-shank or screws does as well). It changes the resonant frequency of the floor. It helps prior to the installation of the subflooring by keeping the joists upright and moving size to side. It does NOT increase strength for a distributed load, only a point load. It does add to the dead weight of the floor structure.