Radiant floor heat PEX or PE

Slamdvw82716

Doing in-slab heat for a garage and driveway.  While browsing the tubing section at my local Big Box store...  they have landscaping black PE tubing in 500' rolls... a LOT cheaper than the PEX 100 foot rolls.



I plan on running a home built, open to the atmosphere waste oil boiler anyway, so I am not too concerned with Oxygen



What harm or good would it do to run with the cheaper tubing?



My line of thinking is: It should work.  The tubing is designed to be buried and live outdoors.



A quick search didn't pop up any answers.



Thanks

Robert Avery

SpeyFitter

PE not rated for such.

PE can NOT handle the temperatures you will put in radiant floors, period.

kcopp

ditto

It might "work" for a few hours but I envision a real mess. kpc

CMadatMe

Sure It Will Work

Until it bursts and you have to dig up the driveway. Now what costs less?

Slamdvw82716

gonna go with PEX..

Thanks for the quick replies.



Just to play devil's advocate...



How much temperature are we talking?  I couldn't  picture much more than 100*F

How much pressure we talking? ... it works for sprinklers



If this wasn't such a large and expensive project ( for me.. ) i'd try it and see what happens. 



But after thinking about it... I will be using PEX.

zacmobile

to add a couple points

1) make sure you don't bed the pipe right in the asphalt if you are doing blacktop, cover the pipe with a layer of sand first. the pex may get eaten by the tar over time or may melt from the hot asphalt during installation.



2) use something larger than 1/2", snowmelt usually requires quite high flow rates, sometimes up to 3 gpm per loop depending on your design.



in order to get the surface warm enough to melt snow it may require fairly high temperatures to accomplish the task depending on your winter conditions where you are, probably beyond the limits of PE pipe.



oh, and insulate the area to be melted too, especially the edges, or you can lose up to half your input energy into the ether instead of the snow.

NRT_Rob

if you're doing snowmelt

water temps could rise much higher than 100 degrees. 130-140 is the max for concrete. if you're doing a sand bed it could probably go even higher.