Pole Barn radiant - random one-off questions!

[Snarf77]

Pole Barn Foam, Pex, and Manifold questions

I've been reading now for some months (what a great resource) and my pole barn is about half built. I'm thinking towards next steps pre-concrete. Though I've read a lot, I still have questions.

Barn specs:

30x50x12, R19 in walls and R30 in ceiling. Set 11" from compacted dirt to allow for 4" compacted 57 stone, vapor barrier, 2" 25psi foam, and 5"of concrete. Questions:

My mud board (lowest horizontal board) is above grade. To prep for concrete, I was thinking about installing a lower 2x4 board along the outside under mud board and installing the 2" foam vertically within the wall area against the 2x4. This would serve as the necessary insulation and hold in the gravel as it is compacted? Any issues? - This would require the vapor barrier to go vertical inside of the wall after the flat foam is put down...

Should the vertical foam go to finished floor level or higher as I'm insulating walls.

PEX - Is the expensive barrier pex (HePex) worth the double/triple cost of basic barrier pex (i.e. online/ebay)? I figured on buying in lengths divisible by my loop length with little scrap.

I'll only get as far as the manifold before winter but want to go ahead and order one so the system is under pressure for concrete install. Like the pex - there are cheaper stainless models and more expensive ones. Is there a (somewhat) agreed upon brand/model for 4-5 loops? I'd like it to last.

Those questions will get me to the next step if any advice can be given!

 

[Kaizen]

Re: Pole Barn Foam, Pex, and Manifold questions

Yes get oxygen barrier pipe or your pumps and equipment will have rust issues. Stainless will last for manifold. Really depends what setup you will have. Mine has little zone things on it. If you're just going to put under pressure just leave extra pipe and connect them with fittings and a pressure and fill setup. Doesn't have to be pretty.


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[seanc_mt]

Having your insulation on the inside is fine. For pex in the floor use Pex-A from supply house.

 

[Black Oak]

Your location is needed to best help you. It sounds like you are gonna do fine.

 

[Snarf77]

Having your insulation on the inside is fine. For pex in the floor use Pex-A from supply house.

Is that THIS product? There is no "A" product but there is the Pex-AL-Pex..which i did not think was correct.

Your location is needed to best help you. It sounds like you are gonna do fine.

Top of Maryland at Pennsylvania line.

just leave extra pipe and connect them with fittings and a pressure and fill setup. Doesn't have to be pretty.

Very good point! I didn't think of that as an option..dope. Will expedite getting the concrete poured if I don't have to source and install the manifold immediately.

 

[Snarf77]

I believe I'm going to go with a Blue Ridge Company pole barn pex package.

HERE

Seems like they have everything I need to get the pipe in the concrete before winter. Then I can worry about the mechanicals later. The only problem I see is that the "package" includes a manifold, which I wouldn't need if I went with an all in one panel system. Those just seem convenient.

 

[Black Oak]

I'm confused. What exactly is an all in one panel system ? Does this replace a manifold? How many loops are you planning on? A pre-fab panel with pumps / exp. chamber etc. is used in addition to the manifold , unless you have found one that includes a manifold.

 

[Snarf77]

I'm confused. What exactly is an all in one panel system ? Does this replace a manifold? How many loops are you planning on? A pre-fab panel with pumps / exp. chamber etc. is used in addition to the manifold , unless you have found one that includes a manifold.

Forgive my layperson terminology. The panels are simply received and wall mounted. Looks to include the manifold per zone requirements. Hook up loops and go (obviously slightly more complicated). Link:

Check this out

5 loops x 300 feet in the 30x50 barn 12" on center.

 

[Firebrick43]

Running the foam vertical is correct. Cut the upper edge at a 45 degree angle so the high tip is the level of the poured floor. The plastic should go on top the foam not underneath.

Use pex a oxygen barrier. It has much better kink resistance than pex b. If you kink pex b or c your really supposed to cut it out and splice which is not a good idea in a floor.

Also you can do propex fitting in pex a. Buy the Milwaukee tool for $400 and you can resale later for $350 on eBay. The crimp type fittings with pex b and c restrict flow significantly compared to the propex type fitting.

If you do the loops carefully and get them within a foot or two in length you can use much cheaper manifolds with just ball valves. The expensive ones have flow controls to allow installers to be lazy and use various length loops. If the loops are various lengths without flow controls the short loops will get all. The flow and little to nothing through the long ones.

Pex a oxygen barrier can be found economically from supplyhouse.com. Quick and free delivery over $100. Never had to wait over three days.

http://www.supplyhouse.com/Mr-PEX-1220030-1-2-Mr-PEX-Oxygen-Barrier-PEX-Tubing-300-ft-coil

Buy 300ft coils as a 1000 really ***** to unroll. I won't try it again.

I sure hope your not considering electric boilers for the size of building your doing?

 

[79rallysport]

The plastic should go on top the foam not underneath.

I put the vapor barrier under the foam when I did my pole barn with radiant. And from my research, is the best way to do it. It protects the foam from ground moisture which over time will degrade it.

 

[Black Oak]

Thats interesting, I haven't seen one that included the manifold. Learn something every day .

 

[Firebrick43]

I put the vapor barrier under the foam when I did my pole barn with radiant. And from my research, is the best way to do it. It protects the foam from ground moisture which over time will degrade it.

https://buildingscience.com/documents/insights/bsi-059-slab-happy

 

[seanc_mt]

Is that THIS product? There is no "A" product but there is the Pex-AL-Pex..which i did not think was correct.


That is pex b you want:

http://www.supplyhouse.com/Wirsbo-Uponor-F2060500-1-2-AQUAPEX-Red-300-ft-coil-2187000-p

 

[4cyclic]

Blue Ridge is a very good supplier. Got all my stuff from them, very happy.

 

[Modoc]

Blue ridge is where I'm getting my materials also. Great people to work with, Brian was very knowledgeable and helpful with working out the final details for my install.