The wife and I are building our own home and are getting close to the time to pour our floor. The main floor was designed and built to support a 2" over pour of concrete. I would like advice regarding a few things. `1) Do I need to put a 6-10mil poly barrier on the subfloor prior to laying out the pex. `2) Any advice on staplers vs individual hammer driven staples? Brands of good tools, pneumatic, spring loaded, ect. `3) Re inforcement of the slab. (Have concidered placing 6" mesh over the pex.) `4) Any suggestions or tips would be greatly appreciated. ` Thanks Kim

These are question for your designer. Your questions are easily answered by several manufacturers design and installation manuals. This is not something you should trust to "design-by-internet". Stapling your own tube to the deck? Which staple, which tools? The manufacturer of the PEX dictates these things and hangs his warranty on the specification.

No poly, but a sealer is recommended.

Reinforcement determined by floor finish among other things.

Tip: If the material supplier does not offer design find an independent to help before you buy materials for your radiant floor heating project.

Right, you need to do a proper design analysis BEFORE doing a proper installation.

If you elect to hire a company to accomplish either, check their credentials BEFORE hiring them. Even a simple Google search with the company name and problems or complaints in the search field may be very revealing.

If you elect to accomplish this DIY, get a copy of John Siegenthaler’s Modern Hydronic Heating and study up. We have free DIY heat loss analysis and HR floor heating design software on our website:

http://www.borstengineeringconstruction.com/Heat_Loss_Analysis_Calculator.html

http://www.borstengineeringconstruction.com/Hydronic_Radiant_Floor_Heating_Design_Calculator.html

Please be sure to read the associated instructions for the software. All is very clearly explained.

I have gotten some professional design help but felt that it was only so so and should be taken with a grain of salt. A bit of history I got some great advice on this web site about 3 years ago and that was the same advice I am getting now. That being to "get professional help." I have a few excuses though I live 20 minutes outside of a 1horse town a couple hundread miles from anywhere big enough to have an certified HVAC/Hydronic designer. As it turned out the local plumbing wholesaler that I deal with provides that service free of charge to it's customers. I Met up with the fellow in the big city one day (Made a day trip out of it.) And a week or so later he got back to me with a nice fancy schematic and a quote with a list of required components.

The next day I went into the plumbing wholesaler in town and started getting some more info on some of the things. And when the staff saw the list and started saying things like "What kind of boiler is that? Why did that designer not specify the kind of boilers that we have in stock here all the time, carry all the parts for ect. ect." The manager of the branch personally apologized to me on behalf of his company. They set me up with probably the most reputable plumbing company in town and they installed the same size boiler as the designer specified but pretty much everything else is different (More pumps / less automated control valves) and did the work as well as provided all the components for less then the quote.

So I now have all the part of it in my utility room I have 8 zones (250ft loops) on one manifold running the basement and the plumber is waiting for me to install the floor loops and do the pour before he hooks the rest of it all up. I asked him about a loop plan and he said just start laying out loops and keep them the same length as the basement ones. When I asked about a pex stapler he never hear of one. The people at the plumbing wholesalers never heard of them either.

So any opinions you may have about tools or procedures will be extremely useful to us hicks out here in the sticks.

So what kind of a sealer are you talking about something like a spray on membrane?

Thanks
Kim

Good luck on your floor. I think laying plastic down is optional, I did it on my first 300 sqft, but not on the remaining 2 pours of 1000 sqft each. I found it best and cheapest to nail down zip ties with staples (the heavy duty type, not the staple gun type) http://www.homedepot.com/p/Grip-Rite-3-4-in-Hot-Dip-Galvanized-Staples-1-lb-Pack-34HGPNS1/100148501 and then strap the tube to the zip tie.

I spray paint my tubing loop pattern on the floor and then staple down then zip ties and then run the tubing down to the floor with the zip ties.

I have used regular concrete for all my pours with a pumper truck.

I use a thermostat to turn on and off the pumps when I need heat and have a geo water heater to heat the water.

Posted By newbostonconst on 23 Jul 2014 06:28 AM
I found it best and cheapest to nail down zip ties with staples (the heavy duty type, not the staple gun type) http://www.homedepot.com/p/Grip-Rite-3-4-in-Hot-Dip-Galvanized-Staples-1-lb-Pack-34HGPNS1/100148501 and then strap the tube to the zip tie.

I spray paint my tubing loop pattern on the floor and then staple down then zip ties and then run the tubing down to the floor with the zip ties.

Thanks for your input on this it is comforting to know that someone ells is also running all pumps instead of control valves. I have to say though as I think about your method of attaching the pex seems like a heck of a lot of work compaired to a staple gun that can be run with an extended handle to avoid getting down on your knees. Also thanks for confirming the concrete type. Kim

Back in the 90's I managed a hydronic distribution company that specialized in radiant floor heating and heated driveways most of which were driven by one for the first condensing boilers and residential indirect water heaters built in the USA. We designed complete systems and shipped them out on pallets with an CAD drawing showing licensed contractors exactly how to install our systems. Some of these systems were installed on Islands, so being in the sticks (where I came from) is no excuse for compromise.

A savvy radiant floor designer/supplier will design a system for you (not pawn you off to some DIY webpage) and provide direction, starting with a room-by-room ACCA Manual 'J' heat load with CAD layout of your PEX tubing. The technique or installation procedure is dictated by the manufacturer or best practice determined by those whom are licensed and factory-trained to install such systems.

Yes, it can indeed be very challenging finding a good HVAC company (or really a good contractor in any discipline), especially in rural areas. Even in populated areas that have good HVAC regulations (e.g., knowledge, experience, licensing, insurance and bonding requirements), enforcement can be inadequate and you really need to carefully check credentials before hiring. In some areas and for people having the right stuff, DIY may be the best alternative. Anyhow, we have provided our recommendations and good luck with your project.

Yes and those recommendations given a few years back to get professional help did spur me to get it. At the time I found online heat loss calculators came back with very mixed results. Fluctuating from 170,000 - 240,000 BTU (I tried several not sure if I tried the ones provided by BORST). In the end I eventually developed my own spreadsheet that came close to what the designer in the city said they were. And also came close to the 200,000 BTU that the plumber installed here for me so I feel confident that I have that right.

Now apart from loop layout all the design work is done. That is why I ask a few questions about tools and practices. I strongly agree with you regarding a DIY guy with the right stuff being the best alternative. I have seen a lot of shoddy I don't care work done by so called professionals. That is why I came here to ask these few simple questions regarding a good stapler and proper practices for membrane, tube installation ect. ect. Because obviously I can not seem to get that here where I live. Fortunately there are a few users here interested in passing on there opinions and tips on such things and not just a bunch of professionals telling us DIY guys to give it up and leave it to them. So does someone want to give me quote to travel from mid continent USA to the toolies of Alberta to install a few thousand feet of pex pipe? (I think not) But if I keep asking here and there sooner or later someone will tell me how pleases they are with this brand of pex stapler or how much they hated that brand because it kept doing......

You know I could of followed the schematic from the designer and not hired the local plumber and ended up with a system that cost me 25% more to install (Spent a week installing it and been a nightmare to run with mixing valves at every manifold and 30 more electronic servos and control circuits to fail. But my "Design by Internet" has led me to become somewhat knowledgable on the subject. And gave me the ability to ask some very right questions that eventually led me to the plumber who installed the boiler for me.

Kim

Precisely Kim, knowledge is always a good thing to have when dealing with construction contractors. When a company goes out of their way to discourage homeowners from considering DIY, you should consider applying due diligence. We were motivated and developed the DIY software on our website largely from our own first-hand experience with so-called “pros” and from requests from people like yourself who didn’t have any other option except DIY.

BTW, while a PEX CAD layout is useful for visualizing what needs to be accomplished, it is not absolutely necessary. What is absolutely necessary is actually installing the PEX in such a way that each circuit length is actually very close to the required circuit design length. The best installers just adhere to the PEX layout best practices defined/explained in John Siegenthaler’s Modern Hydronic Heating and work directly from the numerical circuit design lengths without even using a PEX CAD layout. There are many companies that will provide you a “free” PEX CAD layout if you purchase PEX or other HR floor heating system components from them. However, these companies often don’t accomplish a proper design to obtain the proper circuit lengths. You should apply due diligence if these companies can’t provide you the required circuit flow rates (and associated balance valve settings to obtain them), the selected pump showing where it will actually operate on the pump performance curve, and the required heat source supply temp. Again, having the basic knowledge of what constitutes a proper HR floor heating design is a good thing.