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swesna

tile for tub surround

swesna
13 years ago

OK...we have cement backer board installed around our tub. Also, there is a window that will have tile installed inside the jamb. The window has a two inch jamb and is a fiberglass awning window.

Also, the backer board is not level with the green board. It should have potentially needed to be shimmed to meet the green board more evenly. The back board is about an 1/8 to a 1/4 inch lower than the green board in some places. Mainly in the front of the tub where the back board would meet the green board.

My friend the plumber started to install the tile onto the backer board, NOT where the backer board meets the green board. But the tile is not coming out smooth. For example, the edges of one tile are not level with the next. The tile is porcelain and are 8 X 12 inches each. He used the mastic pre-mixed to place the tile onto the backer board and used a 1/4 X 3/8 floor trowel.

I saw numerous postings NOT to use mastic pre-mix to place the tile onto the backer board.

Also, I am thinking the 1/4 X 3/8 trowel is placing too much mastic onto the walls.

Question 1: What type of trowel should be used to place the tile onto the wall?

Question 2: Should I remove all of the tile and replace the backer board. This time shimming the backer board in order for it to meet the green board evenly.

Question 3: Should I go out and buy Laticrete 255?

Question 4: Based on what I am reading does the backer board need to be sealed? I am sure back in the day the only thing behind tile was regular sheet rock...are we really saying that we now need to use backer board and then coat it with something to make it water proof. Is the cement fiber board not water proof enough or a hell of a lot better than ordinary sheet rock which is in most houses in the US.

Any help would be appreciated...Thanks in advance.

Steve

Comments (23)

  • MongoCT
    13 years ago

    Was anything like plastic sheeting or tar paper put between the cement board and the framing?

    Regardless, with the issues you have...

    1) remove any tile
    2) take down the backer board.

    Mastic can sometimes be re-emulsified with water, so scrape off what you can, then soak any tiles in water. That might help soften any remaining mastic, allowing you to get them cleaner.

    3) Remove the cement board.
    4) Get someone to rip down a 2x4 into whatever thickness you need to shim the cement board out so the face of the cement board will be flush with the face of the greenboard. Nail those rips to the faces of the wall studs.

    Tangent alert: While we're on the subject of "greenboard", do know that greenboard can;t be used asa tile backer in a wet area like a shower or tub surround. Above the tile it can be, but no down lower. Terminate tangent.

    5) With the studs built out, now add your drainage plane, either 6-mil poly sheeting or lapped tar paper. Staple it to the built-out studs.

    6) You can reuse your old cement board. Flip it over and put the old mastic-y side inwards and have the clean side facing outwards.

    7) Mix up some thinset, buy a roll of mesh tape (looks like drywall tape but it's alkali-resistant mesh tape) and tape and thinset the cement board seams. DO NOT put on so much thinset that you have humps on the seams. Use a drywall knife to keep the thinset/mesh in plane with the face of the cement board.

    8) Thinset and tile with powdered thinset. A bagged modified thinset that you just add water to will be fine.

    The above isn't the only way, just a simple recommendation.

    Your Questions:

    1) 1/4" by 1/4" square-notched trowel
    2) See above
    3) You can use 255 if you'd like
    4) Either use the poly/tar paper behind the cement board or use a topical membrane on the face of the cement board. Like RedGard, HydroBan, Ultraset, HPG, etc.

    Cement board isn't waterproof, water can pass through it. But it will not be degraded or damaged by water. Sheetrock will absorb the water and be destroyed by the water. Including greenboard.

  • swesna
    Original Author
    13 years ago

    Thanks for the response...there is no waterproof layer between the cement board and studs. Are you guys really saying that tar paper can just be stapled behind the cement board? Does it have to overlap the lip of the tub?

    I have plenty of staples and tar paper in the garage so that would be the easiest and cheapest.

    Could I use the same powdered thinset for the walls as the floors? When you say modified are you saying with a vinyl adhesive?

    Thanks again...it sucks to redo work...we bought this house 8 months ago and have not even slept in it yet. That is why I was hoping my friend the plumber could knock this out but I was not happy with how his tiles were matching next to each other...so I am going to do it myself.

    One more question...does the size of the tile make it easier or harder to do a bathtub area? I am willing to change it for ease of install.

    Thanks,
    Steve

  • MongoCT
    13 years ago

    Yes, tar paper run horizontally, lapped for drainage, and simply lapped over the lip of the tub flange. Sounds silly, but it does the trick.

    Same thinset for floors and walls? Yes. Bagged powdered thinset comes it two basic varieties; unmodified and modified. Modified had latex polymer additives that improve bond performance already added to the powdered mix. Or you can buy unmodified and add liquid latex admix to the thinset when you mix it up. In general, using already modified is easier as it's already proportioned for you.

    Most thinset manufacturers have an unmodified thinset for about $10 a bag, a lightly modified for $20, and a highly modified for $30. Give or take a couple of dollars.

    Tile size can be an issue. While large tile can cover a wall quickly, if the wall is even a bit out of flat the large tile can rock over and bumps on the wall. if the tiles are not perfectly sized, which often times non-rectified tiles are not, they can be slightly out of square, or slightly out of flat. Any dimensional issues with tile will be exacerbated with large tile.

    On the flip side, while small mosaic tile conform to wall deformities, small tile also means a lot of grout lines, lots of fudging to keep things lines up, etc.

    If you get into the medium-sized tile, in the 4" to 6" range, and you're looking for the easiest installation, consider a self-spacing ceramic tile that has spacing nubs on the edge of the tile. You just stack away, coverage can go fast. No need for tile spacers, they space themselves.

    A 12" tile should not pose a problem. But it's sort of the transitional size going from easier (smaller) to larger (more difficult).

    Consider layout before you commit to s tile size. Cut lines, etc, and where they will fall.

    Enjoy!

  • swesna
    Original Author
    13 years ago

    Thanks again...

    Just curious if the water were to get through the group and then the cement board. It would then end up hitting the tar paper and dripping down to the lip of the tub which is caulked. If there was a leak there then the water would just sit there. Does not sound too great...I think the best would be to stop the water from getting through the cement board.

    The mastic my friend used was actually pre-mixed thin set but I think I saw someone state that was not much different than mastic as far as how it reacts to water. Is that true?

    Thanks again.

    Steve

  • MongoCT
    13 years ago

    Pre-mixed, like in a plastic tub?

    Now I'll have to admit, that product used to pretty bad. But recently I thought Bill posted something about a new formulation, but I'm not sure if it was for a plastic tub thinset or grout.

    The goal of the membrane is to keep the moisture away from the wall framing. Typically it'll dry back into the bathroom through the grout, which it typically the way it got behind the tile.

    If you had an excessive leak, say missing grout or a cracked tile, the mount of water getting behind the tile would be more than could dry back out. It'll show as wet grout at the bottom of the wall. Which is better than not knowing until you have nasty wet stuff going on in the framing bays.

    Not that its worth anything, but I've never seen interior wall damage when a membrane has been used behind cement board.

    If you want to use a topical membrane, a trowel- or roll-on like HydroBan or RedGard, have at it. It gets applied to the cement board, and when it dries you tile directly on it. Whichever product you chose read the installation instructions carefully. Coating thickness, number of coats, and if reinforcing fabric is required in corners or on the cement board seams.

    If you haven't tiled a tub surround before, a good way to go is to draw a starter line for the bottom of the second course of tile and tile off that. Example: Let's say you're using 4" square tiles with a 1/8" grout line. Your second course of tile will be 1/8" + 4" + 1/8", or 4-1/4" above the tub.

    Draw a level line at that height on the three walls. I use pieces of angle iron that I have specifically for this purpose, but you can use a straight stiff board, or a level. This will act as a ledger board for you. Set the top of the board at the line, use something to shim it to that height. Now thinset above and you can use that ledger board to support the first row of tile that you set. It'll give you a great starting line for the remainder of the tiles.

    When done with the wall, remove the ledger and set the bottom or first row of tile.

    This might help

  • swesna
    Original Author
    13 years ago

    Thanks again...

    Is this stuff OK ??

    The one that we used is called Simple Set Thin-Set Mortar. This is a pre-mixed thin-set sold in a 3.5 gallon bucket.

    I did not like the way it looked like it was going on the walls. But I have only done floors before and used normal thin-set for that.

    This crap was $40 so I hope I can continue to use. If not I might take it back to HD to get a refund :)

    Steve

  • MongoCT
    13 years ago

    I believe it's a mastic. It's not something that I'd use in any sort of wet area. HOWEVER, that's personal opinion.

    The "by the book" answer is that while it can't be used for shower floors or anywhere in a steam shower, it can be used for "shower walls and tub surrounds."

    The reason it can't be used on shower floors or in a steam shower is that the water exposure will re-emulsify or cause the mastic to go soft and mushy.

    Mastics do need exposure to air to dry and firm up. So if you are using large tile, over 6" square for example, I'd contact their tech department and ask how long you need to wait before grouting. You want the mastic completely cured prior to grouting. Not just at the edges of the tile, but behind the center of the tile too. Grouting will reduce the mastic's exposure to free and and hinder its ability to dry and harden.

    If you choose to shift gears, Home Depot carries Custom thinsets. They have VersaBond which is lightly modified and FlexBond which is heavily modified. I'm guessing $20 and $30 a bag respectively. Either would be fine for your application.

  • swesna
    Original Author
    13 years ago

    Thanks. I am pretty sure that I can return the bucket of pre-mixed thinset.

    Then I will get the ones you suggested. I would rather be safe then sorry.

    Also, if I go through the task of removing the tiles and the backer board. I might then do a niche which I did not even think of previously. But this would make me feel the rework is worth it.

    I actually have a deeper wall on the opposite wall from the shower head wall. I think the wall is about 5 1/2 inches thick there. I will have to read up on how to create this either tomorrow or Friday night.

    Then after building that I will put up either new or the old backer board as you suggested previously. Then use that water sealer over the backer board.

    There are two sealers available at HD and Lowes. One is made by Laticrete at Lowes and the other is that Red blah blah at HD.

    Are either of these any good? I dont want to spend $50 on it if they are not good. I could also put up the tar paper behind the backer board as well. The stuff is free since I have plenty in the garage from a previous project.

    Thanks again...I will be glad to get this project back on track. I will not feel like it is back on track until I get at least two rows of tile back up properly.

    Steve

  • MongoCT
    13 years ago

    I'd recommend Laticrete's HydroBan over Custom's RedGard. HydroBan isn't good, it's excellent. RedGard is good. My opinion.

    Whenever a niche is built from scratch I'd recommend a topical waterproofing membrane within the niche itself and on the cement board on the niche wall out about 6-12 inches around the face of the niche. That's for a shower built with poly or felt behind the cement board.

    Or omit the poly/felt and just Hydroban the entire shower.

  • swesna
    Original Author
    13 years ago

    They have Laticrete WaterTight at Lowes...is this good?

    Laticrete even shows this on their web site

    http://www.laticrete.com/homeowners/products/waterproofing_anti-fracture.aspx

    Thanks,
    Steve

  • swesna
    Original Author
    13 years ago

    Well today I took off the backer board with the tile attached. That was a difficult process...the tile was adhered pretty well to the backer board.

    Ok...now I have a question. It does not make any sense to me that the backer board is actually 3/8 and the green board is 1/2. Well I guess that makes sense because that is the way it is.

    But what does not make sense is to shim out the backer board to meet the green board.

    Do you guys actually suggest this??

    Or should the thin set just go on thicker where the backer board is and thinner where the green board is so the tile sits level?

    My wife and I are thinking about having an entire tile cover the transition. For example, if the tile is 8 X 12 and we have them go vertical then have 4 on the backer board and 4 on the green board.

    Also, we have a window in our tub that we would like to tile around. Should we meet the bottom of the window with a full tile do we dont have to cut out around the window or is it OK to make the L type cuts around the window?

    The issue is either there is a little over 48" between the bottom of the window and the lip of the tub. I am not sure what is more important to have a full tile above the bath tub or a full tile below the window? I know the answer could be it is our preference but I want to hear from the pros...what do you think?

    Should we center the back of the tub on the window or on the tub? The window is not perfectly centers...it is off to the left by 1.5 inches.

    Should we center on the shower head or have the tiles grout line be on center with the shower head?

    Thanks in advance again :)
    Steve

  • bill_vincent
    13 years ago

    One question I have before anything-- I'm curious why the Durock and greenboard would not match up. I'm hoping the Durock you're using is 1/2" thick?

  • swesna
    Original Author
    13 years ago

    Bill,

    No that is the point...I am using hardi backer and it is actually 3/8 inches. I assumed it was 1/2 and thought maybe I installed 5/8 green board. But no it is 3/8 and the green board is 1/2.

    It sucks but I figured that must be normal since that is what they are selling at the HD.

    Steve

  • swesna
    Original Author
    13 years ago

    I just looked up Durock at Lowes and they have it in 1/2 thickness...I guess I will be getting that tomorrow...that sucks that I wasted time getting the HardieBacker again which I was assuming to be 1/2 but it was 3/8. Having the green board and cement board match up will help me I am sure.

    Thanks Bill...

    Can you let me know what you think about the other questions or positioning of the tile.

    Thanks in advance,
    Steve

  • swesna
    Original Author
    13 years ago

    OK put up the durock. That is actually a 1/2 inch. The durock does not seem as good as the hariebacker board because it cracks easier when working with. But as I said the hardiebacker is 3/8 of an inch even though at lowes it claims it is 1/2 inch and will match up with the green board.

    The only wall I did not cover yet with the durock is the wall were I would like to put a niche. My wall there is 6" deep.

    Can someone give me an idea of how I should lay out my tile which is suppose to be 8 X 12 but is actually 7 3/4 X 11 3/4.

    Also, does the redguard go over the durock prior to putting the tape over the seams? I am assuming so since the tape is held in by the thin set.

    Please let me know because I am going to try and get this tile during my next 3 day weekend which is next week.

    Thanks again,
    Steve

  • bill_vincent
    13 years ago

    Hi Steve-- sorry I've been a little scarce lately-- alot of 12-14 hour days lately. :-) I didn't address any of your other questions before because Mongo seemed to have it pretty well in hand.

    As for Durock vs. Hardibacker, my preference is actually for Durock. Much easier to work with, and once installed, every bit as strong. I like the bond between tile and Durock better, too, and that's most important.

    As for your layout, it sounds to me like the tile was designed for a 1/4" grout joint. But for my taste, that'd be too big a joint. I'd prefer to keep it closer to 3/16- 1/8", depending on how bad the sizing or squareness of the tile is.

    As for the waterproofing, if you're going to waterproof over the cement board, you want to tape and thinset those tape joints first. Just try and keep the thinset as flat to the cement board as is humanly possible. But you need to have a continuous membrane, so the joints must be taped and thinsetted first.

  • yacoobsyifa06
    13 years ago

    more information about tub surrounds installation..how to fix it....maybe this site can help you......

    Here is a link that might be useful: Tub Surround

  • swesna
    Original Author
    13 years ago

    Bill,

    Thanks for the response. I am in no rush and understand you guys have more to do than answer questions here.

    OK...I will thinset the tape joints first and then waterproof. Do I have to do the corner too?

    Can you or Mongo answer my questions about tile layout? I am going to go with a 1/8 of an inch grout line. At least when you but the tile up to each other they seem to be tapered and have a space at the front of the tile and meet at the back. This seems to be making a 1/8 grout line.

    Thanks,
    Steve

  • swesna
    Original Author
    13 years ago

    also, there are gaps between the green board and the durock do I fill these with thinset as well?

    Before we did the hardieboard and then the green board...then spackled the green board so it was all nice and snug except for the 1/8 difference in plane.

    Thanks,
    Steve

  • swesna
    Original Author
    13 years ago

    What is interesting my wife and I are still trying to make sure we like the tile we picked. We actually want to install a tile that we like, is good quality and installs easy.

    My friend when he was installing the tile installed them right next to one another. The edges of the tile are sloped but there is no bump or anything on them. When I look at a 4 X 4 I see the bump on the side to provide a space. That is great. But is the sloped edge providing you a consistent space for the grout line too?

    We were at the good old HD again and noticed these 8 X 12 were spaced apart maybe 1/8 of an inch. I never noticed the 1/8 of an inch spacers.

    So, was there more going wrong with my friends job that just the fact he was not laying them smooth next to one another. ie he was also not creating the grout line properly??

    Are the tile w/ a bump on them good to buy? is this a quality tile?

    Based on the comments from Bill the rectified tile are the best but would those have a bump on those? I am thinking not. Also, I would not think the side would be sloped.

    Thanks,
    Steve

  • MongoCT
    13 years ago

    Funny, this thread disappeared on me for a few days.

    Rectified don't have a bump, rectified are sawn to size after a sheet is fired, so the sides are usually nice sharp 90's and the tiles are quite uniform in size.

    The bumps or "nubs" work very well. Just get your first course dead level and the rest will stack like...tile.

    I never butt non-nubbed tiles to one another. With the edge as you describe you'll end up with a "V" shaped grout joint instead of a "!_!" shaped joint, if there were any problems it's possible that the grout could more easily pop out of the "V". Could be a nonsensical thought, but hey, that's me.

    I think HD has 1/8" tile spacers.

    Going backwards, if you're doing a trowel-on membrane, then read the installation instructions. They're on the manufacturer's website in pdf format. They might even have videos on Youtube. Regardless, yes, cement board seams and corners, pretty much any joint that is going to get a roll-on membrane, should be thinsetted and mesh taped.

    Got to run...

  • swesna
    Original Author
    13 years ago

    Mongo,

    Thanks...

    I agree that the grout would have been put into a V shaped grove.

    The only tiles I have seen with the "nubs" have been ceramic.

    At least I know that I will use the 1/8 inch spacers.

    When I tile around my window, which I am going to tile completely around below/sides/and above, how should I tile the jamb? The jamb is a little larger than the 3" bullnose tiles at the bottom. I was thinking of using 3" bullnose in the jamb completely and having it hang over the edge. But it may only make sense to do that on the bottom .... what is standard here? I will have a 1/4 or 1/2 gap between the window and the tile.

    I really think I want to lie the 7 3/4 X 11 3/4 horizontally in a brick pattern. 5 tiles will cover the back wall of the tub and 3.5 on the sides.

    Thanks again,
    Steve

  • swesna
    Original Author
    13 years ago

    how long should I wait to use hydroban after sealing joints with mesh and thin set?

    I am a little worried that putting the hydroban on too quickly after thin setting the joints and niche that it may stop the thin set from curing.

    I thin setted one joint between the durock, the corners around the bottom and sides of a window, my niche and where the tops/sides of the durock meets the green board (above and in front of my shower).

    I thin setted in the afternoon and then went home to eat and shower. I then went back to my other house and started to apply the hydro ban above these areas except for the ones that had not dried totally (mainly the gaps between the durock and green board).

    Can I apply another coat to these area and then the field tomorrow?

    I read this on the Laticrete web site...does this apply to the thin set mortar being used to seal the corners/joints/niche etc. ? I am thinking this is talking about a floor application and hoping not thin set.

    9. Allow wet mortars/plasters (deck mud consistency) to cure for 72 hours at 70°F (21°C) prior to installing LATICRETE Wateright Floor N Wall Waterproofing & Crack Isolation.

    BTW my niche came out great so far...It is huge because one of my walls along the shower is 6" deep.

    Thanks,
    Steve