Replies

1. 
   Mongo | Oct 14, 2003 03:06pm | #1

   The climate panels are wood. Flooring is tile. RFH is in the wood climate panel. Wood and tile have different coefficients of expansion. Over time, it's possible, and likely, that the thinset holding the tle to the climate panel could break bond.

   While the panels have Al to help promote more even heat distribution, the cement board also give you more thermal mass...not much, but a little...and this would help minimize striping in the heat distribution.

   My opinion? You'd get a better floor system, structurally and thermally, using the cement board.

1. 
   TurtleBoy | Nov 24, 2003 06:56am | #3

   Mongo,

   I ended up putting down 1/4" hardiebacker over the RFH. I mapped out each sheet prior to insatlling over the thinset. I went back and drove in screws with the lay out on the sheet, I felt much safer.

   But know this brings up another question. I'll be putting down some Mirage Engineered Pre-finished Birch over the same RFH system. I tried to run the tubes parrallel with the floor joist as I know the flooring will be going perpendicular to the joist and tubes making it easier to see the tubes. The flooring is 3/8" thick (or should I say thin) total and it is 3-1/4" wide. I went with this because it is supposed to be very stable and didn't want any unnessisary R-value or height added to the floor. I'm reading the info that comes with it and it says that I should add a layer of 3/8" plywood prior to putting down the floor.

   I'm not into adding anymore, just don't have the time , money, or desire, also the installer , not the sales man< wants to staple the floor down. I don't have a problem with that as long as he can see the tubes. It's where the tubes turn or where they are not at the regular 7" spacing that I am concerned. I told both the installer, who stopped by the house, and the sales person, who also stopped by the house that I want it glued in certain areas. The sales guy is like he'll glue it. The installer is like I'll glue it but... I told the installer that where he had to he could face nail in addition to the glue.

   How the hell can I map it so he doesn't hit any tubing? I thought about some poly and than tracing it out. After the floor is glued he can put the poly overf the floor and hell he can even nail though it.

   Do you have any advice on this? I hope I didn't put you to sleep.

   Thanks in advance turtleboy.

1. 
   DavidThomas | Nov 24, 2003 12:14pm | #4

   "How the hell can I map it so he doesn't hit any tubing? I thought about some poly and than tracing it out. After the floor is glued he can put the poly overf the floor and hell he can even nail though it."

   Best way is to mark it out on graph paper before the floor is poured/tile laid. I've got those diagrams for all my structures. Only used it once to powder-actuated hammer in some nails, but it's still nice to have it on file for future options.

   Barring that: Start with a cold floor. Turn the heat on. Mop it really lightly with water and see where it evaporates first. Mark with chaulk and then draw your map, drill the holes, etc.David Thomas   Overlooking Cook Inlet in Kenai, Alaska

1. 
   TurtleBoy | Nov 25, 2003 07:21am | #9

   Thanks for the info, The graph paper would go with the blue-prints and the other method will due if I forget where the hell I put the graph.

   Thanks Turtle boy

2. 
   KCPLG | Nov 25, 2003 12:13am | #6

   turtle

   check and see if anyone has a thermal imaging camera in your area. Turn on system wait for 5 minutes and take pictures.

1. 
   TurtleBoy | Nov 25, 2003 07:16am | #7

   That gives me a reason to become a voleenteer fireman. Good Idea

   Thanks Turtleboy

3. 
   Mongo | Nov 25, 2003 10:26pm | #11

   Opinions:

   I don't like nailing or stapling 3/8ths strip flooring. It can be done, but I don't prefer to do it. With the thinner product, sometimes the staples/nails, instead of compressing the material as they penetrate, displace it, and you can end up with very subtle bumbs where the fasteners are. It's not going to happen all the time, but it'll likely happen some of the time. These bumps usually are so subtle that they can't really be felt underfoot, but they are enough to change the way light reflects off the flooring, and that is what makes them visible. A big problem? No. But it may cause you style points.

   Finding the tubing. I've used David's water wash technique on PEX embedded in slab and gypcrete, but never on cb over a climate panel. It may work. Still...whenever you fasten into a radiant floor like yours, you run a risk. Even with a perfectly mapped out floor plan, when flooring, the installer gets onto the zone and may go fastener-happy..."pow...pow...pow...pow...pffffsssst...oh crap!"...and accidentally pop one through the tubing.

   I've never glued over cb, so...

   I called Bostik's tech department and we chewed a bit over your predicament. The tech guru felt there would be no problem at all using Bostiks Best to adhere your flooring to the CB.

   Bostiks was already mentioned in the thread (can't see right now who it was), but if you're going to an adhesive, it's the best one out there to use. It's the only one that I'd use in my own house. In your case it's good over RFH, and it can work with the subfloor/underlayment assembly you already have in place.

   Added bonus is that height-wise, the bostiks/mirage should be a close match to the thinset/tile that you're putting elsewhere.

   Do monitor the water and floor temp when you first fire the system up. The climate panels should give you a nice even heat distribution, and over the long term, you don't want to overtemp the adhesive or the flooring.

   Warm-footedly,

   Mongo

1. 
   TurtleBoy | Nov 27, 2003 06:56am | #13

   Mongo,

   I'll be giving thanks tomorrow for the help I have received from you and others like you on this forum.

   Thanks again for all the tips, Turtleboy

2. 
   Danusan11 | Oct 14, 2003 03:10pm | #2

   thinset, cement board, tile do it right the first time.

3. 
   gdavis62 | Nov 24, 2003 08:25pm | #5

   Glue your wood floor down with Bostik's Best urethane.  That is what I did with my engineered wood floor over radiant.

1. 
   TurtleBoy | Nov 25, 2003 07:18am | #8

   Did you have anything between the radiant and the engineered flooring? Like another layer of plywood?

   Turtleboy

1. 
   gdavis62 | Nov 25, 2003 06:59pm | #10

   Nope.  The floor structure is I-joist, 16" ctrs, 3/4" Advantech sheathing, staple-up tubing underneath, glue is put on the well-cleaned sheathing with a notched trowel, and the engineered flooring strips are bedded in the glue. 

4. 
   PHILLK | Nov 26, 2003 07:03am | #12

   It sounds like you have a similar situation which I had w/ my rad floor and tile. I layed 1/2 cement board rather than a warm-board product. I then pured light-weight conc in the grooves to smooth things out. My tile installer then installed a slip sheet which is vinyl sheet flooring. this was glued down then scuffed up and then a thin mortar film was spread over the surface. Then the tiling proceeded. Attatched are some photos, hope this helps.

   tub1.jpg is prior to filling and slip sheet

   tub4.jpg is after slip sheeting and skimming

   
1. 
   moltenmetal | Nov 27, 2003 04:03pm | #14

   Wow PhillK- that looks absolutely great!  The heated tub lip is a really nice feature!

   Let me get this straight: you ripped a bunch of strips of cement board and laid it down between the rows of tubing, and did a lot of coping at the curved ends, then filled in the gaps with "lightweight concrete".  That sounds like a very good alternative to the "warm board" method under a tile floor, since the cement board is quite conductive and has a lot of heat storage capacity for a toasty and even-temperatured floor.   This sounds like a nice method for the radiant floor-heated bathroom and kitchen I'm planning.

   What confuses me a bit is that your tile guy put down a "slip sheet" and then laid the tile on top of that.  I'm wondering why he didn't just lay the tile directly on top of your cement board?  Why would you need a slippage plane between the cement board and the tile layer?  Both are going to get heated up, and the difference in expansion between the two should be pretty small- so why the slip sheet?

1. 
   PHILLK | Nov 29, 2003 12:19am | #15

   m.m.

   Actually I laid the cement board strips first, then I stapled down the tubing. I used 5/8" cdx for the rest of the house where ther'es hardwood and carpet. Real slick system. The reason for the slip-sheet was one fore added insurance against cracking. But mainly, because there are so many joints in the cement board and tubing, it would have been too labor intencive to tape each joint, adding another layer of cement board would have maid the transitions between tile and hardwood/carpet unacceptable. as it is my hardwood flushes out perfectly with the tile and I'll have to float the carpet up 1/4".

1. 
   MikeSmith | Jan 12, 2005 11:34pm | #16

   good discussion.. i've been to turtle's house.. his floors came out greatMike Smith Rhode Island : Design / Build / Repair / Restore

5. 
   ronaldrady | Jan 12, 2005 11:48pm | #17

   A digital infrared thermometer, or a laser temp gun works well to detect heat tubes. Let the system cool off then run hot water through the tubes. It works for finding leaks in concrete slab heating tubes aslo.