Tiling/Floor Experts needed

[Coley]

Ok guys, I'm looking for some experts in flooring and tiling, here is my situation and what I currently have:
-5/8" T&G plywood (basement) subfloor sitting on 2x4's (on the flat) spaced at 24" o/c on a concrete slab.
Now, I want to put down not only tile on this, but a heated floor within that.
So I would like to know about the 'next layer' on top of this 5/8" plywood prior to tiling and heating pad/floor stuff in order to avoid floor cracking etc but also to promote a heated floor?
-ie:.....1/4"? plywood to thicken up the existing floor rigidity?
(note: I would be screwing all of this stuff down probably at 6" intervals...not nailing)
or....3/8" plywood to bring the floor up to a full 1" thick?
or....1/4" cement backer board
or some other surface layer product before the tile...or?
Anyone who has some good, seasoned and successful insight into this....I'm all ears.
Again Many Thanks!
Coley

[LockDoc]

-
Well, it's been a while since I installed floors and I'm sure things have changed, but I always recommended a 3/4" T&G plywood sub floor with a 1/4" underlayment on top of that for vinyl tile and sheet vinyl flooring. I always used 1/4" Luan plywood for underlayment. If you are on 24" centers with your floor joists I would want a minimum of 1" total thickness floor. If you are talking about installing ceramic tile I wouldn't be comfortable with the 24" center floor joists with that. Too much movement in the wood between the joists and the grout will eventually crack and crumble. When not installing ceramic tile directly on concrete always use cement board, unless there is something newer and better out there.

LockDoc

[kingsolver72]

If you're installing ceramic or a porcelain tile you'll want to use a Hardie backer or Duroc.. cement board. If you're installing a DuraCeramic, Adura or any LVT(luxury vinyl tile) you'll want to use Certiply or a 1/4" birch underlay. I would not use Luan... I've heard it has a tendency to delaminate. YouTube will help you for sure.

[LockDoc]

Originally Posted by kingsolver72

If you're installing ceramic or a porcelain tile you'll want to use a Hardie backer or Duroc.. cement board. If you're installing a DuraCeramic, Adura or any LVT(luxury vinyl tile) you'll want to use Certiply or a 1/4" birch underlay. I would not use Luan... I've heard it has a tendency to delaminate. YouTube will help you for sure.

The quality of the 1/4" Luan must have really went down hill since I used it the last time. That stuff used to be bullet proof....

LockDoc

[87max]

Electric or pipe heat? Personally I would ditch the subfloor and go over the concrete. If pipe grout over it and then schluter. If you want to keep the subfloor check the schluter website to see the specs for 24" centers. I always use schluter no exceptions.

[GR8-68]

I would not tile on a floor with 24" centers it is sure to crack, to much deflection. Really if you were doing tile you did not need anything on the concrete

[davischevy]

Ditch all the wood, fasten your heat tubes to the concrete floor, grout to the top of the tubes and install tile.

No flex, no termites, no bugs, no problem.

[Coley]

Good info so far guys...many thanks.
Let me 're-zero' things up a bit....going back to the original 80 year old concrete floor is not on and not an option...it is out of level and simply not a good surface so that is off the menu.
So that leaves me with the 5/8" t&g plywood on 24" o/c...so that is my starting point.
Now, based on some of the comments.....I like the 1" thick concept which would be the 5/8" + another layer of 3/8" on top of that.
As for the schluter stuff....is that a waterproof membrane or a hard board of sorts?
As for the in-floor heating system it will be an electric type (Tru-comfort/home depot brand) at this point.
As for the duro type cement board....is that only for shower and bath walls?....or is it also used for flooring?
Ok, I'll leave off from there and again many thanks for the incoming info!!....much appreciated.
All Good
Coley

['63GENIII]

While Ive never installed Tru Heat, I have installed countless NuHeat systems which I guess are the same. It gets laid into a layer of Thinset with another layer on top to bury it, tile on top. Please do not forget the thermostat sensors that get laid in with the mats. I have had to repair 3 separate jobs that the home owners forgot these simple parts and it cost each of them a mint for me to fix it for them.


I would agree with others here on the 24" joist spacing and the 5/8" ply. I think you'll experience enough deflection to start seeing cracks. I think cracks combined with the heat mat installed may not work out too well and you could end up with failure of the mats. Just did my bathroom a few years ago. Used 3/4 ply then 1/4 hardibacker with tile on top. 16" centers on joists. Theres no movement at all in the floor.

BTW, I may not have seen it but what is the square footage of the basement? Reason I ask is for the electrical load that you are going to be figuring in to supply the mat(s). I have seen them in 120v and 220v configurations. Are these the standard residential voltages in Canada?

[pritch]

Originally Posted by davischevy

Ditch all the wood, fasten your heat tubes to the concrete floor, grout to the top of the tubes and install tile.

No flex, no termites, no bugs, no problem.

He could level that old floor some, too. What's minimum covering for radiant? Seems like a couple inches at least. Fiber mesh would hold it all together. I've never really heard of the electric-mat systems lasting very long, and they do spin the old meter.

Is gas available? Gas-fired boiler with hot water tubes is about the most efficient, I think.

[davischevy]

Originally Posted by pritch

He could level that old floor some, too. What's minimum covering for radiant? Seems like a couple inches at least. Fiber mesh would hold it all together. I've never really heard of the electric-mat systems lasting very long, and they do spin the old meter.

Is gas available? Gas-fired boiler with hot water tubes is about the most efficient, I think.

What he said.

[Coley]

yep....I get that 5/8" on 24" o/c is not going to cut it, thus the addition of another layer.
So, let's go there.
The actual heating square footage is not that big or great...probably less than 100 ft2 all in or close...in an odd 'u' shaped configuration in and thru a 'galley' u shaped kitchen.
So back to the 2nd layer....plywood or 'duroc' or whatever?...what is the next best layer to put on the 5/8"?...plywood? or a stiffer cement type board?
all good and again many thanks for the input.
(also...good info on the temp sensor, I would not forget this)
Coley

[LockDoc]

Originally Posted by Coley

yep....I get that 5/8" on 24" o/c is not going to cut it, thus the addition of another layer.
So, let's go there.
The actual heating square footage is not that big or great...probably less than 100 ft2 all in or close...in an odd 'u' shaped configuration in and thru a 'galley' u shaped kitchen.
So back to the 2nd layer....plywood or 'duroc' or whatever?...what is the next best layer to put on the 5/8"?...plywood? or a stiffer cement type board?
all good and again many thanks for the input.
(also...good info on the temp sensor, I would not forget this)
Coley

As I mentioned in my first post, even with the second layer I wouldn't put ceramic on a floor with 24" on center joists....

Just my 2¢ worth....

LockDoc


LockDoc

[saxart]

Originally Posted by LockDoc

As I mentioned in my first post, even with the second layer I wouldn't put ceramic on a floor with 24" on center joists....

Just my 2¢ worth....

This!!! You cannot tile over a 24" on-center set up, I don't care how thick you go with the wood over the top. Your tile and grout will crack IF it even stays stuck down.

You have concrete, that's the best subfloor you could ask for with tile. Rip out the wood, and use a self-leveling floor leveler to make the floor flat again. That will be a rock solid set up. If you must leave the wood subfloor for some reason, then I would think about installing a hardwood floor. That can withstand the flexing you'll get.

[68c10airstream]

check into a total system called "schluter" and their product line of floor heat is called "detra heat" The schluter system uses a styrafoam type of panel with a fibrous covering and their claim to fame is what they call "uncoupling" of the substrate. Download the manual and i believe youtube has videos. I remember about 2 years ago watching a video of them making a complete shower enclosure and surrounding room with divider walls made with the various thickness styrafoam panels glued together with their proprietary adhesive and metal edging. They even make seating out of the styrafoam sheets. I will be doing their system soon in my bathroom remodel including a steam shower with a tiled enclosure.

I contacted a consulting firm regarding my steam system and mentioned using the schluter system and he said "that's the best there is and he used it in his parents steam shower install".

The schluter manual talks about floor requirements for tiled floors and what is needed for their shower drain pan system.

I'm hiring the tile job and the installer said he will only install schluter and has laid tile for 20 years with the best long lasting results from using schluter.

[68C15]

Why not pull the plywood, add more supports, insulate, then do the regular tile work as you would on a main floor?

My old house had 12" tile on kitchen floor. It was 16" on center with 3/4" plywood under and even that had cracking grout

[68C15]

They make self stick vinyl tiles that look just like regular tile. Cheaper, easier and no cracking worries. I'd still insulate under the subfloor.

[special-K]

The only deflection we are concerned with here is in the plywood. I think that can be dealt with. If it were joists spanning open area at 24" O.C. the deflection issue would be multiplied greatly due to the deflection of the joists themselves cmbined with the flex in the sub floor. Is height a concern? Could you add another full layer of plywood? At 5/8" you would have a 1 1/4" sub floor. I'd glue and screw that. If that doesn't seem feasible, how about pulling up plywood and adding 2x4s between to gain 12" O.C? The Schluter products do nothing to solve this issue and is something to consider separately. I've seen plenty of large tile floor done properly to hold up for decades before anyone here ever heard of Schulter products. There are other options...and much much cheaper. IMO, that stuff is overkill and an unnecessary added expense in your application. In areas like bathrooms where waterproof is a concern, I use Schluter products exclusively.

In my upstairs bathroom, I have a tile floor. My log house was built in 1857 and the hand-hewn floor beams span 16", range in dimension between 4" & 5", with the space between 21"-24". The original floor is t&g 1x, I ran tapered splines perpendicular to framing to level floor, added 5/8" plywood with luan underlayment, mastic, and tile. It has held up just fine for 30 years. I'm not contradicting what others have said, except for the only way to go comments. There's more than one way to skin a cat