Figure 8

Now that your floor looks like a can of silly string exploded (figure 8 ) its time to add more layers to it and cover up all your hard work.  If you have not yet done all the hard work then your floor doesn’t look like that. Check out How to install WarmWire Part 1. I’ll wait.

Okay, you may want to check out a speed reading class. Just sayin’. My preferred method is Schluter Ditra underlayment installed atop the WarmWire for your tile installation.

The best method of leveling out your floor for your Ditra would be an SLC or Self-Leveling Cement. This product is mixed with water and poured over your WarmWire. When mixed properly (follow the instructions to the letter – really) and poured it will – wait for it – level itself. When cured you will be left with a level, flat floor.

You can actually install your tile directly to this layer if you chose to do so. I do not chose to do so. I prefer to have an additional uncoupling membrane above these layers then my tile. That’s just how I roll.

For purposes of speed (SLC requires 24 hours to cure) I will level the floor above the wires with mortar. If you chose to do this, and you may since it is considerably less expensive, you need to take absolute care with the method I utilize. You risk damaging the wire while leveling the floor so be careful.

To level the floor above the WarmWire with mortar I use a 3/16″ square notch trowel. Mine is metal – yours should not be! You can purchase a plastic trowel make exclusively for use over the wire. These are much safer to use as they would require actually trying to damage the wire with it. It’s difficult to damage it accidentally if you use the plastic version.

The most difficult thing to do over in-floor heating elements is installing tile properly. That means flat, flat, flat. By using the ditra and utilizing my method you will begin your tile installation with a flat substrate over the heating element.

I mix my mortar (thinset) fairly thick for this. It assists in holding the shape and getting absolute coverage with the mortar – no voids in the mortar bed. I will first use the flat side of my trowel and fill all the areas between the wires moving my trowel in the same direction the wires are running.

Filled and Combed

In the left side of this photo I have the flat troweled the mortar and in the right side it is ‘combed’. Notice everything is running the same direction as the heating wires.

Once that is all filled in I will flip the trowel over to the grooved side and ‘comb’ the thinset in the same direction by placing the trowel so the wires are between the grooves. That is so that the teeth of the trowel are actually touching the floor beneath the wire and the wires are between the notches. This will give you a grooved bed on which to install your Ditra.

Once that is finished place your Ditra over the top and grab your straight edge, level, 2 x 4, or whatever you have that is straight and handy. You want to press the Ditra into the thinset to it fully embeds into the fleece on the back of the Ditra. Place your straight edge on top of the Ditra and run it back and forth in the direction the wires are running or at a slight angle (figure 9).

Figure 9

If you run your straight edge in the other direction you will end up with a roller coaster for a floor. Your straight edge will go from the top of the wires into the spaces between the wires and back up. It will not be flat if you do it in this manner. By keeping it either in the same direction, or a 45 degree angle, as the wires it will always remain on top of the wires for the length of your straight edge. Your floor will come out flat and even.

You need to make sure you put enough pressure on the straight edge to embed the Ditra fleece into the thinset. If you stand back you can see the difference in the color or shade through the top of the Ditra. It will turn a darker shade when embedded correctly and you will be able to see any spots you may have missed.

Flat!

Embedded and not

The left side of this photo shows the Ditra embedded correctly and the right side the Ditra is simply laid onto the mortar bed without embedding it yet.

Simply keep doing this as you walk (crawl) your way out of the room. Be careful not to step or kneel on any parts you’ve finished. There is a considerable amount of mortar beneath your Ditra so it is easy to put ‘dents’ in it with your foot or knee. As long as you use a fairly decently sized straight edge you should end up with a perfectly flat, stable floor ready for the tile of your dreams.

After 24 hours you can walk on the Ditra to wire your heating element and install your tile. You need to wait this long for it to cure. Stepping or crawling on it prematurely will create dents or otherwise compromise your membrane and substrate. Be patient.

Contractor Glamour Shot!

Wiring the control box and heating element is fairly straightforward. Read through the directions included with your control box to ensure it is wired the same as I am describing – it may not be. I don’t know, I can’t see it from here.

There are three things you need to attach to the control box: the power from the house, the heating element, and the temperature control probe. The power from the house gets wired to the ‘LINE’ side of the control box and the heating element is wired to the ‘LOAD’ side.

The power from the house consists of three wires. They should be white, black, and ground which is usually green or a bare copper wire. The ground is not wired to the box, only to the heating element. The black is wired to the black and white to white of the control box. Easy enough even if you’re colorblind. The black wire is the hot wire! It’s not like your car radio in high school. The white is neutral. This is the way it should be but I didn’t wire your house so don’t blame me if it isn’t.

Figure 10

The probe has two wires – red and black. They are wired into the appropriate clips in the back of the control box.

The heating element has white, black, and silver. White to white, black to black, silver to ground. Please note that in this photo (figure 10) I have two different heating elements running to the control box so there is twice as much electrical spaghetti hanging out of the wall. You should not have that many wires.

After it is all wired up just stuff all the wires straight back into the box and

Figure 11

attach the control box to the wall. The face of the control box is plugged into the back plate with the pin cluster in the back of it (figure 11). Place it in there carefully. They bend easily if not lined up correctly – just trust me on that one without testing it for yourself.

Now you can turn the breaker back on. Oh, you turned that off, didn’t you? Sorry, if you are currently sporting a Yahoo Serious hairdo, it may be my fault. You want to turn the breaker off before you start wiring.

Now the bad news – after you install your tile you must wait 3 – 6 days before turning on your underfloor heating. You need to give your mortar plenty of time to fully (relatively) cure before zapping it with unnatural heat. Doing it sooner may compromise the strength of the mortar and, in turn, your tile installation. You don’t want to do that now, do you?

Warm Tootsies!

You’ll just have to wear socks for a couple of more days.

There you go – warm tootsies for those cold mornings. If this has helped you out please send me a photo of your completed tile installation. I would love to see what people do with my good advice and bad humor. I keep tellin’ my wife that it is a great combination but, you know, she doesn’t believe me. Oh well, extreme jackassery is getting to be my tag line so why quit what works?

Send me your photos at FloorElf@FloorElf.com and lets see what you can do.

One of the best upgrades for a bathroom or kitchen tile floor is the use of in-floor heating. There are several different products available to accomplish the coveted ‘warm tootsies when it is forty below’. One of the more popular products (around here, anyway) is the Suntouch WarmWire radiant in-floor heating. That’s just a really long term for wires that heat your floor (and warm your tootsies).

Now that I’ve used the word ‘tootsies’ twice in one paragraph I believe it’s time to move on.

As an ‘official’ reference the manufacturer’s installation guide can be found online in one of those fancy-ass pdf thingies HERE.  It contains all sorts of things that you need to be aware of before starting your installation. While this post will walk you through how I do it, your installation may differ in aspects of which you are unaware. You need to read through the manufacturers information as well before you actually install you WarmWire.

This is as close as I’ll ever get to an official disclaimer: Be aware that the methods I use will differ somewhat from the manufacturer’s instructions intended for the do-it-yourselfer. I am a professional tile guy (really – what are you laughing about?) I accept liability with everything I touch in a customer’s home and accept that risk with the methods I choose to utilize. Read the manufacturer’s instructions before installing your WarmWire!

This information focuses on the installation of the substrate below the WarmWire, the installation of the wire, and the installation of the Schluter Ditra membrane above the wire for the purpose of tile installation. The technical aspects of the electrical wiring are covered only briefly and in very basic terms. They are not meant to be a definitive guide to properly wiring the WarmWire underfloor heating element to your control box and power supply. READ THE MANUFACTURER’S INSTRUCTIONS REGARDING YOUR PARTICULAR CONTROL BOX! In English that means if your house blows up it isn’t my fault – I was all the way over here.

In your area it may be required to have an electrician wire your heating element. Check with your local building codes to make sure. If it’s required and you don’t do it you could be in heaps-o-trouble. Don’t mess with the city codes, they’re not very nice if you piss them off. Trust me on that.

Ass covering over – lets get on with it.

The WarmWire system consists of two basic elements – the wire and the control box. The control box is hard-wired to your house’s electrical system and the wire is attached to the control box. The wire is then routed down behind the wall and under your floor. After installed you can essentially control the temperature of your floor tile with the control box.

Before you begin you need to figure out how much WarmWire you need to purchase. The above referenced pdf contains a chart which will explain which wire you need based on the square footage of the floor in which it is being installed. There are three different spacings which can be used and utilize different wattage per square foot. That’s all just confusing crap so I’ll explain it like this: The closer you place your wire the warmer your floor will be – and the more power it will use to accomplish that. Easy enough, yes?

How long your wire needs to be depends on how much square footage you’re heating. The quick way I figure it out is the square footage of the room multiplied by 0.90 (because there is no need to heat along the walls, in closets, etc.) and multiply that by 4.7. That will give you the approximate length of the wire you need.

The wire is available in pre-measured lengths. It is not something you can just order to a specific length. It is a closed loop wire which means it is one complete unit and not a wire that can be cut to length. So you need to figure out the length and order the closest to that number.

The different spacings are 2, 2 1/2, and 3 inches. For the purpose of this post I will use the 2 1/2 inch setting as that will be the most commonly used – and because that’s what I have photos of.  You need to also purchase the wire straps which will attach the wire to the floor and hold it in place while you install your flooring above it. Do not use nails, screw, etc. – use the straps. They have pre-spaced clips to hold the wire in place correctly. And using any other method you risk damaging or severing the wire.

For this particular installation I chose to use 1/2″ Hardiebacker cement board on the floor with the heat wire installed to it. Above that I used Schluter Ditra membrane for the tile substrate. When using Ditra you want your heating element, whether it be the wire, a mat, or other type, beneath the Ditra – not between the Ditra and tile.

You can click on any of the badly taken photos for a full-size version.

Figure 1

Make sure your Hardiebacker, or whichever substrate you use beneath the wire, is installed correctly for a proper tile installation. This is imperative since it is the very base layer for your floor. If not done correctly you risk compromising the entire installation – pay attention, this gets expensive! Read How to Properly Install Backerboard for Floor Tile.  Check out that link – I’ll just sit back here and have a beer Pepsi while you do.

Allrighty! (I can’t believe I just typed that) The first thing to do (after properly installing your substrate – in this case hardiebacker – figure 1) is to install your straps. The metal straps made for WarmWire have tabs every inch. I’m certain you can figure out how to use them for whichever spacing you’ve chosen.

Figure 2

Figure 3

For this particular installation I’ve used every third tab in some areas and every other tab in others. I do this to make the floor warmer in certain areas (in front of the shower and tub) and less so in other areas. I do not know if this is standard practice or not – it is for me. If you are concerned about it please see the ‘disclaimer’ at the top.

The straps are placed on the floor and screwed down. (figures 2, 3)  Suntouch recommends using a spray adhesive to hold the straps in place until you get them screwed down – I do not do this.  I have no problem keeping them where they need to be without it and I do not like any foreign substances beneath my tile installations, especially one to which thinset may or may not adhere.

Tab Spacing

I place the straps every four feet to hold the wires in place. I find this gives me enough hold for what I need to do above the wire before the mortar is fully set. Once that happens they won’t go anywhere anyway. But you do need them to be held in place until that point. Don’t try to use a shortcut with this part, if you damage the wire you’ll need to 1. pay to replace it and 2. start over. Neither of which are my preferred method.

You may want to invest in the electronic box Suntouch makes called the ‘LoudMouth’. It is a small electronic box with a 9 volt battery which you hook the wire to when you start your installation. If you damage or sever the wire at any point the box will scream obscenities at you, call you names, light your dog on fire, or something that will let you know in no uncertain terms that you have screwed the pooch (hopefully not while it was on fire).

If you do damage the wire you can purchase the splice kit with which you can repair the damaged wire. I’ll cover that in another post – hopefully one nobody will need to read.

The end of the WarmWire which is attached to the control box is twice as thick as the heating part of the wire. You need to start your wire placement at the base of the wall beneath the control box. Unroll the WarmWire until you get to the smaller part of the wire – the heating element – and place that part of the wire at the base of your wall. In basic terms you do not want any of the thicker portion of the wire beneath your floor – only the thinner part.

Now the fun part. Starting at the point at the base of your wall start stringing the WarmWire back and forth across your floor utilizing the proper tab spacing for your wire distance. In the close-up photos I have it installed in every third tab. Place the wire beneath the correct tab and push it down to hold it in place. DO NOT use a hammer, screwdriver, or beer bottle Pepsi can to pound or push the tab down.

Figure 4

Figure 5

You want to start at one side of your room and end at the other. You NEVER want to cross the wires over one another. They need to remain a minimum distance of two inches apart at all points. Plan accordingly. This is why you want to get your layout figured before you start.

This is tedious but take your time and get it correct. It is imperative for proper performance of your WarmWire.

Figure 6

The end of the WarmWire is a bit thicker than the wire itself. I will usually take my knife or a screwdriver and cut a small groove into my backerboard or subflooring in which to place the end. Ideally you want the end of the wire to end up at a wall in which case you can simply tuck it between your backerboard and the wall footing (you left a gap there, right?) but sometimes you need to end it in front of your vanity or tub.

I do the same thing with the probe. There is also a temperature probe which must be placed beneath your tile to regulate the temperature. It is thicker than the wire itself also. You can simply cut a groove out of your subflooring in which to place it.

Figure 7

Once you are finished stringing the WarmWire over your floor you need to take care to not abuse it. You can walk on it but don’t dance on it, know what I mean? Take a break – you deserve it. When I sober up post the remainder we will cover how to install Schluter’s Ditra tile membrane over your Suntouch WarmWire for your tile installation.