Tiling questions for my kitchen/bath remodel

[Piston]

I recently completed (well, mostly completed ;D) my bathroom remodel in my home.  The few things I have left to do are trim work, a final coat of paint, and re-tile the floor. 
I've tiled before and consider myself fairly good at it for a DIY'er.  However, I do have some questions.

Since the bathroom floor and kitchen floor are connected, and all the same tile, and we're going to remodel the kitchen next anyways, I'm going to tear up all the old tile/thinset at the same time, and redo all the floors at once.

I wasn't originally planning on re-tiling because the current tile is in fine condition and not outdated, however, since the toilet had a leak that went un-noticed, the plywood under the toilet is starting to rot from all the moisture, and grow mold.  So now we are into a tile job, you know how these things go  :D

Of course I'll fix the leak first, then the floor...after that, I imagine I should use concrete backer board?  Currently, the subfloor is the only thing under the tile, and it is made up of 1X8 diagonal boards going across the joists. 

Do I need concrete backer board?  I'm pretty sure I do, but want to be sure.

If so, how do you apply backer board?  Is it applied with thinset on the subfloor, then the backerboard, and then the special backer board screws?  Similar to laying tile?

Do I need 1/2" or is 1/4" all that is needed? 

I figure out of all the experience on this forum there must be some tiling pros out there!

Thanks in advance, I know you'll be helpful.  ;D

-Matt

[Holmes]

Personally I would not use concrete backer board on top of the diagonal sub floor. Those floors tend to be quite uneven and the backer board can easily crack.  I would put down a 1/2" layer of { solid } underlayment  plywood and tile to the plywood .  The second option is 1/4" underlayment plywood then 1/4" backer board.  I am not a tiling expert but I have seen hundreds of rotted floors under toilets.... ;D

[tyb525]

Yes toilets seem to always leak at some point as a rule. I would put down 3/8" plywood and then that Hardie board stuff, it's thinner and easier to cut than cement boards but does a good job. We always put some thinset under the hardie board before screwing it down, just like you would under the tile.

[Raider Bill]

I recently completed (well, mostly completed ;D) my bathroom remodel in my home.  The few things I have left to do are trim work, a final coat of paint, and re-tile the floor. 
I've tiled before and consider myself fairly good at it for a DIY'er.  However, I do have some questions.

Since the bathroom floor and kitchen floor are connected, and all the same tile, and we're going to remodel the kitchen next anyways, I'm going to tear up all the old tile/thinset at the same time, and redo all the floors at once.

I wasn't originally planning on re-tiling because the current tile is in fine condition and not outdated, however, since the toilet had a leak that went un-noticed, the plywood under the toilet is starting to rot from all the moisture, and grow mold.  So now we are into a tile job, you know how these things go  :D

Of course I'll fix the leak first, then the floor...after that, I imagine I should use concrete backer board?  Currently, the subfloor is the only thing under the tile, and it is made up of 1X8 diagonal boards going across the joists. 

Do I need concrete backer board?  I'm pretty sure I do, but want to be sure.

If so, how do you apply backer board?  Is it applied with thinset on the subfloor, then the backerboard, and then the special backer board screws?  Similar to laying tile?

Do I need 1/2" or is 1/4" all that is needed? 

I figure out of all the experience on this forum there must be some tiling pros out there!

Thanks in advance, I know you'll be helpful.  ;D

-Matt

That's also my plan next week is to paint, tile and trim the master bath at the Tenn. house.

I'm going to thinset and screw the hardi board then tile. Mines only 8X8. Finished the tile / glass block last trip.

Good luck and remember motrin is your friend!

[rooster 58]

    I have done quite a few tile jobs. I use to hekp a friend who was a tile contractor sometimes. Tile mfgrs. recommend that you have at least 1-1/2 total sub floor.
    You do not need to use cement board. When we used cement board we would apply construction adhesive first (liquid nails), and then use screws or nails about every 4". Then apply tile accordingly.
      We mainly would apply 3/8" sb to the sub-floor, using a liberal carpenter glue to adhere the two, with ring shank nails as well. Also with a 4" nailing pattern.
     If you are considering heating the floor, then I would use the cement board

[Piston]

Rooster,
That brings me to another question which I'm glad you brought up.

Currently, the home is heated by forced hot air, which neither my wife nor I like.  It is a very old furnace and I'm anticipating having to replace it in the near future.  We have been thinking of replacing it with a propane furnace, and at that time, adding radiant in floor (actually below floor) heat.  Currently, the floor of the first floor is not insulated from the basement, so I could apply the radiant tubing from underneath, then insulate the floor.

Does this bring up any additional problems?  I really would like to add radiant in the future.  I was told by someone that I have to use the plywood with grooves cut into it to add radiant, and would have to rip up my old floor, but I know that is not true and that you can apply it from underneath, between the joists.  However, I don't know how "involved" that is or what it entails. 

Also, any advice on ripping up the old thinset? 

[tyb525]

I have seen people staple a reflective material over the pex when they add radiant head under the sub-floor. I can't remember exactly what it was, but it reflected the heat upwards without trapping in moisture like fiberglass will do. Basically prevents the heat escaping into the basement/crawlspace. The ones I saw were stapled to the floor joists.

As far as scraping thinset, that's probably one of my least favorite jobs :D

A floor scraper and/or a pry bar with a sharp edge, and lots of time dedicated to scraping....at least that's how it's been on the floor we've done. It rarely pops right off for us, seems we have to scrape every little bit.

If you're putting something over that floor, you don't need to get it perfect as long as you have most of it knocked down, since you'll be putting thinset/liquid nails down anyways and that will give you a bit of a gap.

[Piston]

Hey Tyb,
Thanks for the advice, and Happy Birthday!  This is a big one!

[tyb525]

Thanks! It's all downhill from here huh? ;D Good day for it, I got the day off by coincidence.

[rooster 58]

   Piston, tyb beat me to it He pretty well summed it up foorya. Yes you can install radiant heat now, but I'm not sure to tell you the best way to do it. Maybe consult a contractor? You can also just heat the floor with electrical wire tracing. Not too hard to install

[Holmes]

Piston you can do radiant from under the floor, but if the wood flooring is more than 2" total thickness results may not be satisfactory. To much r value to get the heat where you want it to be.

[beenthere]

To much r value to get the heat where you want it to be.

Also, the mass of the floor has to be heated first to eventually get the heat transferred to the air in the room. Almost need to forsee any temperature drop in advance to heat up the floor before that heat is needed (if that makes sense).

If the heating of the floor is responding to a room thermostat, then the delay in satisfying that set point of the thermostat is going to be pretty long. To add to the mysery, when the thermostat set point is reached, the underfloor heat system will shut off but the extra warm floor will continue to give off heat that isn't wanted at that time.
Similar to having an oversized forced-air furnace that has mass that has to heat up before the blower kicks in, then the blower keeps distributing heat long after the set point of the thermostat is reached and the furnace shuts down just to get plenum temps down to shut-down settings.

[Holmes]

Beenthere you hit that nail on the head ;D well said

[Hilltop366]

I have used a ice scraper to remove tiles from a cement floor, My back liked the long handle, might be too long for a bathroom.

Toilets tend to sweat a fair amount, in the summer mostly, a lot of times they have never leaked but the floor sill will rot.

Beenthere you hit that nail on the head ;D well said

x2

[Don_Papenburg]

How big are the floor joist? Tile likes floors tha tdo not flex much. If you are redoing the whole shootin match .  might consider a mudbed that you put over the sub floor .  Cover subfloor with redrozin paper put down pex and a wire mesh (chicken wire ) then concrete.  About 1" min.  I use 1 1/2" .  Use Nobleseal  crack isolation membrane over the concrete and then tile the room .  Noble seal also waterproofs the subfloor.  Also check out the  John Bridge Forum , I t is the best tile forum on the net. He has caculators that will tell you if your structure needs help or is ok for the tile you plan.

[Piston]

Don, thanks for that info.  That sounds like the right way to do things!  I'd be worried about the floor height at that point though, or rather, the difference between the kitchen and the hardwood living room floor.  I'm not positive on the floor joists, but I believe they are 2x10's, possibly even 2x8's. 

I understand what you guys are saying about the temperature lag that Beenthere explained so well.  How is this problem addressed?  I'd really like to do radiant in the future (probably over a year away at least) if possible.  I have been holding off insulating the basement ceiling just because I want to keep it open until I run the PEX. 

I will have the 3/4" thickness of the subfloor, plus whatever I end up putting on it for plywood or backer board, plus the tile.  It will probably be close to 1.5" thickness.  Does my idea sound like something that would work, or does it sound like I'd do all this work, and then end up with the problem Beenthere pointed out and not be happy with the results? 

I've read on the internet before (so you know it's true :D) that you can put a temperature sensor in the slab when doing radiant in a basement floor, and then the thermostat is based off the floor temp, rather than the room temp.  Is this something that I could do in my situation?  And, would it make the temperature lag any better? 

Thanks again, I'm learning a lot.  It's much nicer to make mistakes in planning than it is to make a huge mistake while doing the job.  ;D

[Hilltop366]

There are outdoor temp sensors systems that will turn on or off heat before it is required to help over come the lag problem.

Heated floors are really nice especially in the bath, it also keeps the toilet and tub warmer, I put the tubing closer together in the bath ( 1/2" pipe, 6" apart) for a warmer floor than the rest of the house without having to add a extra zone.

Seems to me I read that some were using a smaller pipe closer together to make the floor temp more even. Anyone have any experience with this?

I do know that a lot of floor tilers around here will not put ceramic tiles on concrete over wood they have had too many call backs. They will also not put shiny tile on floors due to fear of being sued, way too slippery. I know this one first hand, had some in my utility room and porch, I went out to get an arm load of fire wood at 2-am one night, when I stepped on the tile with some snow on my boot I found myself instantly laying on the ground half in and half out the house with the wood on top of me at -10°c wind blowing 50 mph and the out swing door beating me up wondering if I could get up or not. The tile were gone the next day.

[beenthere]

Hilltop
I know there are those circumstances that require some emergency wood, but a lot more needed 'fixing' in that scenario than the floor tile.  ;D  :

[tyb525]

I think the idea of embedding pex in concrete right below the tile is a good one. But you will still have the "problem" of the floor being a heated mass, concrete/mortar holding heat much longer than wood, but I don't think that is a problem with normal temperature variations.

[Hilltop366]

Hilltop
I know there are those circumstances that require some emergency wood, but a lot more needed 'fixing' in that scenario than the floor tile.  ;D  :

Perhaps I should just move south for the winter....., I did add a store room on the back of my utility room and have a place where I can put 1/2 a cord of wood now but I still prefer to keep most of the wood outside, I seem to get a lot less bugs in the house this way.

[Holmes]

The temp. lag and overheating can be addressed by using an indoor temp sensor with a motorized mixing valve and constant circulation in the radiant floor piping. You can also use an outdoor temp. sensor the same way and get excellent results. Zoning can be done with telestats { zone valves} on each circuit. Look into Viega products. They have a large assortment of mixing stations.

[Don_Papenburg]

I put my 1/2" pex at 6" space for normal heat and then closer 9(about 4")for designed warm spots.

[Piston]

That's a good idea to use closer spacing with the PEX in areas like the bathroom for a warmer floor.  I wish I was at the point now where I could install the radiant as I do the tile floor, however I know the new system will be a long ways away and I'm not 100% committed on doing that yet. 

I'll get the floor down with plans to add radiant from underneath the floor in the future.  In the mean time, I am going to buy one of those heated electric pads that I can put under the bathroom tile.  I see they have a thermostat for those as well and I know the wife will really enjoy getting out of her tub and stepping on the nice warm tile! 

A friend of mine has one of those air chisels and is going to let me borrow that to help in ripping up the thinset.  I hope it works well, I'll let you know  :D 
I'll be starting this project in a little over 2 weeks so I still have some time for research  ;D

Homes,
Thanks for the details and suggestions.

[tyb525]

Keep in mind you should use pex-al-pex since most likely it will be a closed system, it prevents oxygen infiltration which can cause corrosion of the metal parts in the system. Plain pex will allow oxygen in over time.