tile subfloor help

boddah · 01-03-2009, 04:38 PM

after tearing out the tile and lath and ply wood i have 2x6 planks as a subfloor. My question is what next? I did not want the floor sitting too high so was thinking of using that tile backer board 1/4" and scratch coat then tile. Will this work and be strong enough for no cracking?

**Termite** · 01-03-2009, 05:24 PM

2x6 planks will definately be stiff enough for subfloor, assuming your joists aren't spaced unusually far apart. You should lay the 1/4" backerboard in thinset mortar laid with a notched trowel.

bjbatlanta · 01-03-2009, 06:04 PM

Sure they're not 1"x6"'s?? 2"x6" would be really unusual..... Check the tile mfgr.'s specs for recommended subfloor and go by those guidelines so as not to void any warranty.

boddah · 01-03-2009, 06:05 PM

Thinset the underneath of the 1/4" board? alot of it will fall thru the gaps beween the boards. Do i need a scratch coat with lath or can some of those good flexable mortors be good enough on top?

sorry they are 1x6, so will this be strong enough?

bjbatlanta · 01-03-2009, 06:10 PM

No, you will need to use plywood, then your use thinset and screws to attach your 1/4" backerboard to the plywood. There are special screws for this purpose. You should find them in the tile section near the backerboard.

boddah · 01-03-2009, 06:15 PM

Im trying to keep the hight down, so can i use 1/2" plywood with no backer board. And how about the scratch coat vs the flexable thin set?

Carnut12 · 01-03-2009, 06:23 PM

You are not saving much height going to the proper 3/4" plywood, I would suggest using 3/4". Remember this is tile, you do not want the floor to flex with heavy weight on it.

bjbatlanta · 01-03-2009, 06:27 PM

Again, go with the mfgr's. recommendation. There are some tiles that can be applied to plywood without the use of backerboard. You might also try posting on the flooring forum for advice from some tile experts......

angus242 · 01-03-2009, 06:46 PM

Just because you can doesn't mean you should. No one here knows what your joist size is so we cannot properly suggest what needs to go over the planks.
IF you want to install tile correctly, you're going to have to deal with the height.
IF your deflection rating is adequate for ceramic tiling, then you should use exterior grade plywood over the planks. I'd suggest at least 5/8". You screw the ply to the planks, not the joists. You can then use Ditra instead of CBU for the tile under layment. Ditra is only 1/8" thick and a superior material to CBU (easier to install too

).
That would be a preferred installation method vs. 1/2" ply and 1/4" CBU. (which is roughly the same height as the 5/8" ply & Ditra).
While it is technically possible to install tile over the ply, I HIGHLY recommend against it.

and by the way, thinset is NOT flexible.

bjbatlanta · 01-03-2009, 07:05 PM

And there you have it from a pro.......

wineslob · 01-13-2009, 10:42 AM

Quote:

Originally Posted by angus242

Just because you can doesn't mean you should. No one here knows what your joist size is so we cannot properly suggest what needs to go over the planks.
IF you want to install tile correctly, you're going to have to deal with the height.
IF your deflection rating is adequate for ceramic tiling, then you should use exterior grade plywood over the planks. I'd suggest at least 5/8". You screw the ply to the planks, not the joists. You can then use Ditra instead of CBU for the tile under layment. Ditra is only 1/8" thick and a superior material to CBU (easier to install too

).
That would be a preferred installation method vs. 1/2" ply and 1/4" CBU. (which is roughly the same height as the 5/8" ply & Ditra).
While it is technically possible to install tile over the ply, I HIGHLY recommend against it.

and by the way, thinset is NOT flexible.

Thought I'd just "use" this thread as it's what I'm going to be doing.
Quick floor question. (hopefully)
I'm doing a full bathroom remodel. When I get to the flooring we already have the tile we are going to use.
The floor is T&G 1 1/4" fir with what looks like 1/2"X6" planking on top then 3/8" underlayment. Joists are 2X6. Should this be "enough" of a floor for the tile? (don't know what a deflection rating is)
Should I be able to just use tile adhesive and then just grout?
The floor seems VERY sturdy.

TY

angus242 · 01-13-2009, 12:27 PM

Quote:

Originally Posted by wineslob

The floor is T&G 1 1/4" fir with what looks like 1/2"X6" planking on top then 3/8" underlayment. Joists are 2X6. Should this be "enough" of a floor for the tile?
Should I be able to just use tile adhesive and then just grout?

I'm confused. You're saying the subfloor is:
1 1/4" + 1/2" + 3/8"? That would mean a 2 1/8" thick subfloor. Is that correct? Just seems like an odd mixture.
If that is the case, I'd say you could remove the 3/8", use either 1/4" cement backer board or Ditra and then tile. You cannot tile directly over the planks.

wineslob · 01-13-2009, 03:39 PM

Quote:

Originally Posted by angus242

I'm confused. You're saying the subfloor is:
1 1/4" + 1/2" + 3/8"? That would mean a 2 1/8" thick subfloor. Is that correct? Just seems like an odd mixture.
If that is the case, I'd say you could remove the 3/8", use either 1/4" cement backer board or Ditra and then tile. You cannot tile directly over the planks.

Yup. I have no idea why the house was constructed this way.

There's 3/8" particle board (underlayment) on top of the planking. The cement backer may be too expensive for me. (for the whole floor) If need be I'll do it, but it'll have to be over time. (WAF is going to be LOW)

angus242 · 01-13-2009, 04:32 PM

Yes, you need to use 1/4" cement backer board (brand of your choice is fine), use alkali-resistant screws or a roofing nailer with galvanized nails, alkali-resistant mesh tape over the seams and then thinset over the tape.
You definitely need to remove the partical board

wineslob · 01-13-2009, 06:32 PM

TY, I'll post pics when this is done, should be beautiful. (tile floor that is)

Just so I have this straight,( in my head), the backer goes right on top of the 1X6's then after taping, thinset.

01-03-2009, 04:38 PM	#1
boddah Member Join Date: Dec 2007 Posts: 41	tile subfloor help after tearing out the tile and lath and ply wood i have 2x6 planks as a subfloor. My question is what next? I did not want the floor sitting too high so was thinking of using that tile backer board 1/4" and scratch coat then tile. Will this work and be strong enough for no cracking?

01-03-2009, 05:24 PM	#2
Termite Moderator Join Date: Apr 2008 Posts: 6,520	tile subfloor help 2x6 planks will definately be stiff enough for subfloor, assuming your joists aren't spaced unusually far apart. You should lay the 1/4" backerboard in thinset mortar laid with a notched trowel.

01-03-2009, 06:04 PM	#3
bjbatlanta Drywall contractor Join Date: Jul 2008 Location: Lilburn, GA Posts: 2,082	tile subfloor help Sure they're not 1"x6"'s?? 2"x6" would be really unusual..... Check the tile mfgr.'s specs for recommended subfloor and go by those guidelines so as not to void any warranty. __________________ If you can read this, thank a teacher. If you can read this in English, thank a soldier. Support our troops.

01-03-2009, 06:05 PM	#4
boddah Member Join Date: Dec 2007 Posts: 41	tile subfloor help Thinset the underneath of the 1/4" board? alot of it will fall thru the gaps beween the boards. Do i need a scratch coat with lath or can some of those good flexable mortors be good enough on top? sorry they are 1x6, so will this be strong enough? Last edited by boddah; 01-03-2009 at 06:07 PM.

01-03-2009, 06:10 PM	#5
bjbatlanta Drywall contractor Join Date: Jul 2008 Location: Lilburn, GA Posts: 2,082	tile subfloor help No, you will need to use plywood, then your use thinset and screws to attach your 1/4" backerboard to the plywood. There are special screws for this purpose. You should find them in the tile section near the backerboard. __________________ If you can read this, thank a teacher. If you can read this in English, thank a soldier. Support our troops.

tile subfloor help