Hardibacker board- tub,shower wall questions

Discussion in 'Shower & bathtub Forum & Blog' started by elcheapo, Jan 29, 2014.

  1. elcheapo

    elcheapo New Member

    Messages:
    2
    Location:
    Oh
    Hi- I just installed hardibacker board to studs around tub and want to ceramic tile. The hardiboard is not quite 1/2 inch but drywall is, and I didn't shim the board to make it even. Can I lay a coat of thinset mortar over backerboard, let dry and re apply another coat of thinset mortar over dry first coat when I go to apply tile? Or should I just do one heavy coat with a thicker grove trowel? the trowel I have is 1/4"x3/16V but I can get one that is bigger groove? What would be the best thing to do without taking board down and shimming? Also I am going to fibermesh tape all seams and corners with a light coat of thinset but do I use caulk in corners before or after I lay tile or no caulk at all? I appreciate any advice. thanks
    Last edited: Jan 29, 2014
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    21,893
    Location:
    New England
    You can add the mesh tape when you are tiling, or do it before. If you do it before, you're more likely to end up with a speed bump. It's not like you're trying to make a pretty seam like on drywall...you want the mesh there as reinforcement and as long as it's embedded in the thinset under the tile, it doesn't matter when you put it on with one exception - if you add a paint on waterproofing, you need to do it first, let it cure, then add the waterproofing.

    The amount of thinset underneath the tile as it goes from the Hardie to the drywall at the outer edges of the tiled area usually isn't an issue...backbutter those tiles then only run the notched thinset to the edge of the hardie...as long as the majority of the tile is bonded to the Hardie, the little on the drywall won't be an issue if you've put a bit on the back...you want it supported without a gap, but it does not need to be the full depth as the majority of the tile on the Hardie. Otherwise, if you put the full depth of thinset on the drywall as well, unless you push fairly hard, your outer tile will not be in line with the rest of the tile on the wall.

    The bigger issue may be your wall/tub lip and what's behind the Hardie. Unless you are going to use a full waterproofing layer on top of the Hardie, you do want a vapor barrier behind the wall, lapped over the tub's tiling flange to direct any moisture that might get there into the tub, and not down the wall under it. There won't be much, but there it's possible the Hardie may become damp if used frequently...you want to keep that off of the studs.
  3. Justadrip

    Justadrip New Member

    Messages:
    66
    Location:
    New York
    Hi elcheapo.
    Sounds like your starting your first tile project. My suggestion would be to post your question over at www.johnbridge.com . They can walk you through, step by step, from start to finish. John Bridge is a forum dedicated to tile with some of the best in the industry giving advice.
    Keep your plumbing questions here, send the tile and shower construction over there. Proper shower construction and proper tile techniques asked here end up in a pissin contest between guys at John Bridge and a certain someone (John Whipple) who has decided that this site is his own playground and his word is gospel. He is a shill and just a bully.
    So if you want sound advice and a properly built shower and tile job run from here. You will thank me later.
  4. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

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    Location:
    North Vancouver, BC
    El Cheapo on Hardi Backer

    Post(s) removed by John Whipple
    Last edited: Mar 18, 2014
  5. Justadrip

    Justadrip New Member

    Messages:
    66
    Location:
    New York
    Perfect reason to go to www.johnbridge.com Get advice/opinions from many members not just 2. Not only do actual tile setters frequent the forums,many product reps and technical service reps are there to answer any product questions.

    Good way to make friends John,mock his screen name.

    Dont drink the Kool Aid. We have Tang at JB.:)
  6. dhagin

    dhagin builder:anti-builder

    Messages:
    108
    Location:
    oahu
    " Quote Originally Posted by Whipple
    Look at the discussions and you will see that of the men that contribute here it is only I and Roberto who make their living from building bathrooms."

    This is an untrue statement. Some other folks here have been doing this very thing for decades. :)
  7. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

    Messages:
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    Location:
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    Dana - Moderator of the John Bridge Tile Forum

    Post(s) removed by John Whipple
    Last edited: Mar 18, 2014
  8. Justadrip

    Justadrip New Member

    Messages:
    66
    Location:
    New York
    That's a great point JW. How about you go over to John Bridge.com and post that very relevant information? :rolleyes:
  9. eurob

    eurob In the trades

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    449
    Location:
    Montreal
    I hope the Tile Police will not come after me .....:D
  10. dhagin

    dhagin builder:anti-builder

    Messages:
    108
    Location:
    oahu
    They know where you live... just sit there and wait for the knock on the door. ;)
  11. elcheapo

    elcheapo New Member

    Messages:
    2
    Location:
    Oh
    Well- didn't mean to start a war here. No one has any answers for the few questions I asked?
    Can I lay a coat of thinset mortar over backerboard, let dry and re apply another coat of thinset mortar over dry first coat when I go to apply tile? Or should I just do one heavy coat with a thicker grove trowel?
  12. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

    Messages:
    3,944
    Location:
    North Vancouver, BC
    Post(s) removed by John Whipple
    Last edited: Mar 18, 2014
  13. dhagin

    dhagin builder:anti-builder

    Messages:
    108
    Location:
    oahu
    Sorry your questions got missed. :)

    Lets start at the beginning. What size tile are you installing? What do the tile backs look like - are they flat or are there recesses?

    Yes, gap all Hardi board seams - not just the corners - and mud & tape. Mortar needs to be between the boards, so either mortar first & embed tape, or stick tape to the Hardi and smoosh mortar down into the gap.

    After your finished grouting, wait a day or 2 and caulk all interior shower corners with *100% silicone color-matched to the grout*. Many manufacturers make color matched silicone, and if not you can always go here. Don't use latex caulk inside the shower.

    http://colorriteinc.com/color-rite
  14. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,893
    Location:
    New England
    Hardie board is intentionally thinner than the full thickness of 1/2" drywall...it is about the same thickness as the outer edge of the tapered edge common on most drywall produced. Since your thinset under your tile is almost certainly going to be at least 1/16" (the Hardie is 7/16" thick), it's generally no big deal to get the outer tile to lay flat. It does depend on the size of the tile - if the majority is on the Hardie with the desired thinset underneath it, it will be held there fine with a minimal coating under it on the drywall. If this were on the floor, it would be more critical, but as long as there is no gap on the wall, and the majority of the tile is supported on the Hardie, having a bit less thinset on the edge at the drywall isn't going to be any problem.
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