3/4" Pex to foam question

[wuboring]

I ordered all the stuff to put radiant heat in my 54x83. They sent me 3/4" pex instead of 1/2" due to the larger amount of floor space needing to be covered.

I am trying to find out how to attach the pex to the foam board.

they make those handy staples for 1/2" pex, but not 3/4"

any ideas...i guess as a last resort I might zip tie it to the rebar

 

[sippirat]

just my 2 cents but i think the same staples will work. i recently installed the 1/2" and the staples a quit wide at the opening. and even if they are a bit snug on your pex don't sweat it that stuff is tuff. heck the concrete guys roll full wheel barrels right over the rebar and pex

 

[jklingel]

just curious. changing from 1/2" to 3/4" will certainly change your pump sizes, heat output, etc. are you diy-ing this, or has someone actually calc'd all of the necessary specs? an option is to tie the pex to your wire or rebar in your floor instead of stapling it to the xps.

 

[wuboring]

jklingel - I am aware that the 3/4 pex changes alot. My supplier is the biggest geothermal installer in the states right now. I subcontract off of them running a directional boring machine putting in the geothermal loops, so I just had them size the unit to my needs, get the stuff for me, then I am going to install it and hire them hourly if help is needed.

luckily i can bore in the loop feild for the geothermal myself so that is saving me alot of money as well.

the geothermal is expensive to start with but its operating costs should be very low, and I may supplement with wood heat

 

[jklingel]

Wu: roger that. did not know who you were. sounded like the company changed your plans unbeknownst to you. good luck. j

 

[scuba0459]

I would suggest that instead of cable ties you use rebar tie wire. You won't need to trim the excess, it is cheap and it is easy to work with. We did 1000' of pex for my garage floor.

Albert

 

[wuboring]

scuba0459- Did you put yours on top or below the rebar?

My rebar is already down (1/2" on 1ft centers sitting on 2.5" chairs) and im finding it kind of tricky to get it fished under the rebar...but it is doable

i have put 3,000 feet in so far, just need another 500ft or so to finish it up

 

[trythis]

We used zip ties on 6x6 re-mesh. Easy to measure, lots of places to tie it down.

 

[jklingel]

Maybe for someone else following this thread. I am planning a similar deal, only I will embed annealed wire in the 2.5" chairs that I make to hold the rebar or mesh up. If I put the PEX on top (not likely) I can then twist once for the rebar and then have tags lying out for the PEX. PEX on top = faster heat up, PEX on bottom = more even heat, and less chance of The Boneheaded Boss later drilling an anchor for something and hitting the PEX.

 

[Possum]

I put my 3/4 pex on top of the rebar and used rebar ties to hold it. Worked great other than I had to add an additional inch of concrete during my pour to get the what-seems-to-be-the-minimum 2" of concrete thickness above the pex. I have not fired it up yet so I can not weigh in on the depth vs. response debate. I wanted to staple the pex, but could not find a gun or staples that would do 3/4 pex at the time.

 

[jklingel]

Maybe a gun will be available for 5/8 and 3/4" soon, if not already. I wonder why there would not be any? Maybe just the prevalence of the 1/2". Hope your garage works well once you zap the heat to it. I know I worried my a$$ off when we poured my boy's place. PEX embedded in concrete is kind of hard to go back and reorganize.