Radiant heat in Slab. How do I do it?

[Deadman]

I'm building a garage, and want to install in-floor heating in the concrete slab. I'm looking for a "How-To" on installing the Pex piping, and all the tips, tricks, etc to installing it right. Does anyone have any suggestions, or links?

So far, I plan on laying insulation down, laying screen, then laying 1/2 Pex pipe every 12 inches. I need tips on how to do this propperly, and suggestions. My building is going to be 36x60.

Thanks in advance.

 

[cunrya]

you have the right idea. Screen? We just used Wire Mesh Rebar sheets. Wired the Pex loops to it. There is a slick tool that will twist wire (used for aviation safty wire) that speeds things up.

You will need several loops as you don't want to go a certain footage (thinking inthe 150 to 200 range don't recall though for sure)

Use 2" blue board on top of a moisture barrier such as visqueen as well.

Might be beneficial to lay out a couple zones as well in case you ever want to put in an office or something. Put a loop in the pads and sidewalks too, no snow shoveling ever! Wish I would have. Remember oncethe crete is poored you can't change things.

 

[OilHead]

Hydronic's heating off your browser .

 

[mtfallsmikey]

www.heatinghelp.com

Lots of radiant contractors there...on the Wall

If it's a large slab...there are tie tools available to tie PEX to rebar, pipe feeders, etc. Have you done a heat loss calc yet? Uponor has a good manual for this as well.

 

[ericjeeper]

lots of tricks

I have it in my house. Love it absolutely love it.. wonderful heat. Worth every penny.
We installed it ourselves.Lots of zip ties..
Keep your loops all the same length or you can use flow valves. Keep loops under 250 feet each.

 

[Deadman]

Thanks guys great Ideas.

Anyone have any articles on how-to's or anything thats complete?

Its not that hard to do, but I'm sure some milor details are very important.

 

[Wirenut2266]

yup: I thought max zone footage was 300', but 250' is on safe side, that's ok too! Wish I had radiant heat. I just have forced air furnace and wood stove. Oh-well, where's the beer?

 

[CharlieG]

Depends on the pex diameter, but I remember no more than 300' per loop.

 

[abohac]

I'm building a garage, and want to install in-floor heating in the concrete slab. I'm looking for a "How-To" on installing the Pex piping, and all the tips, tricks, etc to installing it right. Does anyone have any suggestions, or links?

So far, I plan on laying insulation down, laying screen, then laying 1/2 Pex pipe every 12 inches. I need tips on how to do this propperly, and suggestions. My building is going to be 36x60.

Thanks in advance.

I used both zip ties and rerod wire (with the spinning tool). Much prefer the zip ties. Build yourself a board to keep your zones correct (drill 5/8 holes twoxtwo so that you can keep track of outgoing water and incoming, Mark one red and one blue also in case something happens. Insulate the side of your slab down at least 6 inches. Put your first run about 6 inches apart next to the wall because it will be coldest there. Go a little outside of an overhead door so that ice doesn't build up and the door doesn't freeze down. Take several pictures incase something goes wrong after cement. Pressurize the system with air and put a gauge on manifold and watch it with a repair coupler handy while finishing cement. When done, get Budweiser. It is the greatest way to heat. I heat my basement, my garage, my bathroom floor (getting out of the shower is neat) and my dads 40x60 shop. You will love it. Good luck and write if you have any questions.

 

[kevinjem]

temp

What the water temp that you guys are running thru your pex?

 

[AKKAMAAN]

I'm building a garage, and want to install in-floor heating in the concrete slab. I'm looking for a "How-To" on installing the Pex piping, and all the tips, tricks, etc to installing it right. Does anyone have any suggestions, or links?

So far, I plan on laying insulation down, laying screen, then laying 1/2 Pex pipe every 12 inches. I need tips on how to do this propperly, and suggestions. My building is going to be 36x60.

Thanks in advance.

Anders, My friend back in Sweden was happy putting in the floor heat coil in the slab. 5 days later he was about to drill holes for his 3000$ auto-lift. He was stuck, couldnt drill untill he knew exact where the tubing was. what to do??
Turn the heat on and go and rent an IR heat dectector camera, and he got a picture showing the the exact tubing layout, within less than a 1/8 of an inch. Now he was smiling....
OK conclusion....make sure you have planned out everything before putting that coil in......

aw come onopcorn:

 

[bassman]

I suggest lots of smaller loops as it is easy to have a big disto block .

Also make sure that the sides of your slab is well insulated as I have seen snow melt in 40 below weather outside of a poorly insulated slab.

also seperate loops for sidewalk are a good idea if the hot water source is cheap .

pexsupply.com

they saved me thousands and they can help as well

 

[Khtsr44]

http://www.radiantdesigninstitute.com/page2.html
Good info in here.

 

[Deadman]

^^^^^^ That site pretty much answered most ALL of my questions.
Great info!

Thanks guys!

I just bought 15 rolls of 250 Foot 1/2 inch Pex pipe. I won't need it all, but I don't want to be short when trying to install it.

 

[Bcat22]

another tip

just thought i would add my two cents. When i installed mine, i had the insulation cut from large blocks of foam by a place that sells pole-barn kits. it ended up costing about a third of what foam board costs and you can get custom sizes(i have 2 inch thick in my floor). i would also recomend slipping a 90 deg peice of plastic pipe over the pex where it comes out of the floor. it will help protect the pex and keep things neater.

 

[mtfallsmikey]

Also...before pouring, take a serious look at insulating under and around the sides of your slab. A tremendous amount of heat gets lost if not done.

 

[deputyrpa]

Also...before pouring, take a serious look at insulating under and around the sides of your slab. A tremendous amount of heat gets lost if not done.

An important point. You MUST isolate your slab from the walls or you will heat the basement walls, loosing it to the surrounding soil and air. Another important note, pressure test your system BEFORE you pour the slabs.

BTW, I used a barrier, then 500psi insulation, and I stapled the pex down using a pex stapler. I fashioned a 1x6 pressure treated wood with schedule 40 elbows to take exit the pex into my utility room. I used 1/2" pex for two zones with four loops each for 1850sqft. I poured 4000psi fiber reinforced concrete in two slabs.

 

[darren_nh]

I used these guys for the kit for my kitchen. They were great and very helpful.

http://www.radiantec.com/index.php