DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Tiling, ceramics, marble (http://www.diychatroom.com/f84/)
-   -   To back butter or not to back butter? (http://www.diychatroom.com/f84/back-butter-not-back-butter-178904/)

fpr4 05-06-2013 08:32 AM

To back butter or not to back butter?
 
I've gotten conflicting info. I am tiling a tub/shower surround as well as the bathroom floor with porcelain tile. Do I need to back butter either? Guy at Lowe's said it was never recommended since it will trap air and cause the mortar to never dry. What should I do?

Also, I have a small area near the supply register opening that is slightly depressed. I noticed this when I dry laid a few tiles over the Hardibacker. For more reasons than I can count, I would prefer not to rip out this section of Hardiboard. I would say it's about 3/32" over a 2 foot stretch but the tile rocks slightly in this area. I haven't put the thin-set in the seams of the Hardiboard yet. Can I apply a little bit of thin set in this area to "bring it back up", let it dry and THEN tile?

Thanks in advance.

pgc555 05-06-2013 04:52 PM

BB or not to BB
 
Fpr4,
Is that your real name?
Now your in my back yard. The guy at Lowe's is wrong about trapping air.
It's just the opposite. By Back Buttering the tile you are creating a bond between the porcelain and the setting materials. When I say back buttering
I'm talking about using the FLAT side of the trowel to apply the thin set.
Here's a video I did showing a test. I also know of a special tool for back buttering tiles. Maybe one of my "buddies" will chime in on that one:whistling2:

http://www.youtube.com/watch?v=bF2SgLBF6qI

Amateuralex 05-07-2013 07:42 AM

Quote:

Originally Posted by fpr4 (Post 1173644)
I've gotten conflicting info. I am tiling a tub/shower surround as well as the bathroom floor with porcelain tile. Do I need to back butter either? Guy at Lowe's said it was never recommended since it will trap air and cause the mortar to never dry. What should I do?

I'd backbutter them.

Quote:

Also, I have a small area near the supply register opening that is slightly depressed. I noticed this when I dry laid a few tiles over the Hardibacker. For more reasons than I can count, I would prefer not to rip out this section of Hardiboard. I would say it's about 3/32" over a 2 foot stretch but the tile rocks slightly in this area. I haven't put the thin-set in the seams of the Hardiboard yet. Can I apply a little bit of thin set in this area to "bring it back up", let it dry and THEN tile?
My understanding is yes, and I've done it several times myself with good results.

JetSwet 05-07-2013 08:26 PM

Back buttering tile should only be done on larger format tile and on walls and if you do one you need to do all of them. I never back butter unless I have to use nails to hold tile from crushing the spacers.

JetSwet 05-07-2013 08:46 PM

Quote:

Originally Posted by pgc555 (Post 1173883)
Fpr4,
Is that your real name?
Now your in my back yard. The guy at Lowe's is wrong about trapping air.
It's just the opposite. By Back Buttering the tile you are creating a bond between the porcelain and the setting materials. When I say back buttering
I'm talking about using the FLAT side of the trowel to apply the thin set.
Here's a video I did showing a test. I also know of a special tool for back buttering tiles. Maybe one of my "buddies" will chime in on that one:whistling2:

http://www.youtube.com/watch?v=bF2SgLBF6qI

Actually the guy at lows isn't wrong if you ever look at a back of a tile...there is a reason why is has a pattern, you take that away when you backbutter.

oh'mike 05-07-2013 09:00 PM

Back buttering helps a lot with certain tiles---and is an absolute necessity,in my opinion, when using rapid setting thinset---

Back buttering is a simple process --like buttering toast---

pgc555 05-07-2013 09:37 PM

Jet,
I'm confused by your comment
Quote:

I never back butter unless I have to use nails to hold tile from crushing the spacers.
Your drive nails into your waterproofed walls to hold up your tile????
Are you confusing back buttering with "back troweling" where you comb the thin set onto the backs of the tile? One more, What is the "reason" there is a pattern on the backs of the tiles?

JetSwet 05-08-2013 05:14 AM

Quote:

Originally Posted by pgc555 (Post 1174699)
Jet,
I'm confused by your comment Your drive nails into your waterproofed walls to hold up your tile????
Are you confusing back buttering with "back troweling" where you comb the thin set onto the backs of the tile? One more, What is the "reason" there is a pattern on the backs of the tiles?

Using floor tiles 12x12 or larger on a wall becomes a different animal. I don't drive them totally through .. tap them in a little. I wouldn't do that if I was using any membrane, only cbu.

You shouldn't butter the entire back like the guy in your video and defently shouldn't push down so hard.... he totally defeated the purposes of trowling. Only the middle of the tile.

jeffnc 05-08-2013 07:01 AM

Quote:

Originally Posted by fpr4 (Post 1173644)
Guy at Lowe's said it was never recommended since it will trap air and cause the mortar to never dry.

This is absolute nonsense and for the life of me I can't imagine what he'd be thinking. Back buttering is basically always going to help create a better bond to the tile in the final setting bed. It doesn't mean you always have to do it because your bond might be good enough anyway, especially on smaller tile. On larger tile with a "waffle" pattern or similar on the back, it's recommended.

Quote:

Originally Posted by fpr4 (Post 1173644)
Also, I have a small area near the supply register opening that is slightly depressed. I noticed this when I dry laid a few tiles over the Hardibacker. For more reasons than I can count, I would prefer not to rip out this section of Hardiboard. I would say it's about 3/32" over a 2 foot stretch but the tile rocks slightly in this area. I haven't put the thin-set in the seams of the Hardiboard yet. Can I apply a little bit of thin set in this area to "bring it back up", let it dry and THEN tile?

Yes.

pgc555 05-08-2013 07:35 AM

Jet,
I am the guy in the video - 42 years experience in the tile trade.
I'm respectfully need to tell you that you are wrong. When your say
that the "tiles are pushed down to hard" Are you saying that you think
by pushing the tiles forward and then pulling back and collapsing the combs of the thinset is WRONG? This video is from the TCNA - The TRAINING
authority for the TCNA seems to disagree with you as well. Although the video is dated, the information is still relevant.
http://www.youtube.com/watch?v=pyt2US_SSBM


I'll agree with the comments that NOT ALL tiles need to BB'd. But 12x12
and larger will most definitely benefit from the process.
This forum is for many DIY'ers looking for sound advice. Again, I respectfully
want to agree to disagree with you.

JetSwet 05-08-2013 08:13 AM

Quote:

Originally Posted by pgc555 (Post 1174890)
Jet,
I am the guy in the video - 42 years experience in the tile trade.
I'm respectfully need to tell you that you are wrong. When your say
that the "tiles are pushed down to hard" Are you saying that you think
by pushing the tiles forward and then pulling back and collapsing the combs of the thinset is WRONG? This video is from the TCNA - The TRAINING
authority for the TCNA seems to disagree with you as well. Although the video is dated, the information is still relevant.
http://www.youtube.com/watch?v=pyt2US_SSBM

I'll agree with the comments that NOT ALL tiles need to BB'd. But 12x12
and larger will most definitely benefit from the process.
This forum is for many DIY'ers looking for sound advice. Again, I respectfully
want to agree to disagree with you.

We can disagree respectfully. Although a lot of people think that back buttering is what is in the your video... what you did was key-in the thinset on the back of the tile....but you already do that on the wall and or floor. I was taught that you butter the middle of the tile like toast....I never end up with butter on the eges of my toast.
As far as laying tile and pressure we can also disagree as well....thanks!

pgc555 05-08-2013 08:24 AM

Jet,
I know this is just semantics. But the DEFINITION - in the tile industry
of "Back Buttering" is using the flat side of the trowel to apply a thin layer
of thin set onto the backs of the tiles.
http://www.youtube.com/watch?v=wu_hqcBTzpY

"Keying-in" the thin set is using the flat side of the trowel to apply thin set
to the substrate first, THEN combing the thin set setting material.

jeffnc 05-08-2013 09:00 AM

In the Tavy video, he is both keying in and back buttering. I wrote a "How To Key In" post in the How To section of this forum which explains keying in. Back buttering waffle tile is similar to the Ditra keying in example in that post.

I'd call scraping the backside of the tile with the flat side of the trowel "micro" keying in, and I'd call filling in the waffle holes "macro" keying in. In effect, back buttering itself is "macro" keying in, and is by far the more important (i.e. just getting the thinset filling in those squares). The harder you scrape, the more "micro" you are keying in, which is obviously helpful, but not the top priority. (When using thinset, enough micro keying in on the tile usually happens by itself IF the thinset is mixed properly, is the correct consistency, and has not been allowed to dry too long or film over.) Having solid mortar support against all areas of the tile is more important than ensuring micro adhesion, because the adhesion that will happen naturally will be enough for most floor applications.

Tavy says you "must, must" back butter the waffle tiles. Any time you hear absolutes like this, of course you can be skeptical. There isn't much that you "must" do when tiling. There are many, many tile installations that are doing just fine that have not been back buttered.

What we're doing is improving the adhesion, improving the coverage, and reducing the *risk* of some sort of failure. It's a good thing to do, but your tile job is not going to implode if you don't. You simply raise the risk of failure - cracked tile, etc.

By the way, I actually do like his tip about covering the corners of the tile. The Tile Council requires min. 85% coverage I believe. Well, if the 15% happens to fall under a slightly high corner (or any corner that has to support a refrigerator rolling over it, for example), then there's a good chance that corner will crack. Making sure the corners are covered is a good idea, since they are the weakest and most vulnerable spot on the tile.

jeffnc 05-08-2013 09:26 AM

I like this video related to back buttering.
http://www.youtube.com/watch?v=bF2SgLBF6qI

Note: many people try to compare the "coverage" of back buttered tiles to non-BB. In general the video experiment is scientific, but that comparison in "coverage" does not work!

Of course the tiles have 100% coverage, you put the thinset there yourself when you back buttered! However, back buttering is not "coverage" per se, in the way the TCNA means it. "Coverage" is supposed to mean "adhered coverage".

For example, let's say you back butter your tiles, then let them cure for a day. Then the next day you actually install your tiles. Then pull them up and look at the coverage. Of course it will look like 100% coverage because all of the time tile is covered. But you already knew that when you back buttered it to begin with. You didn't need to install the tile and pull it up to figure that out.

The only real coverage that counts is adhered coverage. Pulling up the tile and seeing it's back buttered doesn't prove that 100% of the tile actually adhered. You really still don't know.

However, 2 things. First, filling in the waffles means you no longer have any depressions in the tile. You're "fleshing" it out, which means it's more likely the bottom of that thinset will make contact with the troweled on thinset on the floor, increasing adhesion.

Second, the most important aspect of his experiment is the overall higher difficulty he had in removing the back buttered tiles. This proves the adhesion was stronger, and that there actually was more adhered coverage.

When you back butter the tile, you're keying it in. This is a stronger move than merely pressing the tile to the floor. The thinset is well adhered, and then when the wet thinset touches the wet thinset on the floor, that's a much easier bond to make than thinset to dry tile with depressions in it.

jeffnc 05-08-2013 09:31 AM

Quote:

Originally Posted by JetSwet (Post 1174923)
I was taught that you butter the middle of the tile like toast....I never end up with butter on the eges of my toast.

What do you mean by "edges"? The outside area of the bottom of the tile, as opposed to the middle? Or the side edges of the tile, not on the bottom?

If you mean the first, then your way is bad. In fact, it could be worse than not back buttering at all. What you're doing is making it more likely that the outer edges will not be adhered when you install the tile, and this is the most vulnerable area of the tile. If you're going to only back butter part of the tile, then it would be better to butter the outer edges, and leave the middle clear. (As in the Tavy video, just "buttering" the corners of the tiles would help avoid cracking when rolling a refrigerator over it.) But of course that is silly, back butter the whole tile.

If you mean the second, then of course no one is going to butter the side edges of the tile, that's silly.


All times are GMT -5. The time now is 07:22 PM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved