Preparation for Shower and Tub Surround

Posted: January 30, 2010 in Articles, Ceramic Tile & Stone, Projects, Showers & Tubs By: admin

Part 1 of a 2-part series on installing tile for a tub or shower surround. Skip to part 2 here. This article deals with the preparations to tile a tub or shower surround in wood frame structures. It follows the actual work performed on a tub surround project in an Arkansas home.

porcelain-tub-surround01This is Permabase cement board mounted to the studs with 2″ deck screws about every 8″. I cut it with an angle grinder and a 4″ masonry blade. The cutting should be done outside due to the dust it produces. Permabase can be scored and cut, but using a grinder makes a much cleaner and more accurate cut. It’s installed with a ¼” gap above the tub. The joints have been covered with alkali-resistant mesh tape and then filled with thinset. USG mesh tape is sticky  on one side, so it can be put in place on it’s own, then skim-coated. Permabase edges are beveled so that the mesh tape and thinset doesn’t make a hump on the wall. The screw holes have also been skimmed to make a flat surface for the liquid waterproofing. The thinset is allowed to dry overnight.

porcelain-tub-surround02When the walls were framed up for this tub, the opening was a little wider than it needed to be. The studs were also a little out of plumb. I used my table saw and ripped some 1×4′s to the appropriate widths to make the walls plumb, and flush with the lip of the tub. You can see the lighter-colored wood attached to the studs behind the CBU. These furring strips allow the CBU to sit in front of the tub lip, as opposed to bending them out from the framing and making  the  wall  out of plumb in the bottom few inches. As stated before, I used 2″ screws to make sure the screws went through the CBU, the furring strips, and well into the stud. A shorter screw might not have been long enough to reach into the stud.

porcelain-tub-surround03There is a ¼” gap between the Permabase and tub. This joint is filled with silicone. You don’t want the CBU in contact with the tub or wicking will occur, causing  the  bottom  of  the CBU to be saturated. The silicone acts as a “moisture barrier” between the tub and CBU. The silicone needs to be smoothed out so that it doesn’t stand proud of the CBU (raised and uneven) and cause problems later when the tile is put up.

porcelain-tub-surround04Protect your tub with a tarp or heavy paper. Here my tarp slid off the side into the tub during the demolition and a section of old tile fell and chipped the tub. A tub repair kit can be used to repair damage such as this later, but caution is cheaper.

porcelain-tub-surround05 porcelain-tub-surround06Laticrete 9235 liquid waterproofing is applied to the CBU joints with a disposable brush, in conjunction with the 6″ wide fabric supplied with 9235. This strengthens the seams and makes a more monolithic waterproofing membrane.

I then used a standard paint roller to completely cover the CBU with 9235, making sure that every square inch of the CBU is covered. This coat dries fairly quickly (2-3 hours) and a second generous coat is applied to ensure adequate coverage. For the second coat, I painted the two corners and down near the tub with a brush, then rolled the field up to about an inch from the ceiling, which is well above the shower head.

The products used in the preparation phase of this project include the following:

ge-silicone2GE Silicone II® water proof caulk. Caulk that keeps water out is a necessity in areas that will be exposed to water, such as this tub surround, so a permanently waterproof caulk is needed. If the caulk is not permanently waterproof, the area could be left vulnerable to water damage and mold growth.
permabase-cement-boardPermaBase® Cement Board is a rigid substrate made of Portland cement, aggregate and glass mesh that provides an exceptionally hard, durable surface that is able to withstand prolonged exposure to moisture.
laticrete9235LATICRETE 9235 Waterproofing Membrane is a thin, load-bearing waterproofing designed specifically for the special requirements of ceramic tile, stone and brick installations. A self-curing liquid rubber polymer and a reinforcing fabric are quickly applied to form a flexible, seamless waterproofing membrane that bonds to a wide variety of substrates.
usg-tile-backer-tapeUSG Tile Backer Tape USG tapes are made of alkali-resistant, polymer-coated, glass-fiber mesh and are specially designed to reinforce the joints and corners of cement board. Its polymer coating offers protection from high-alkali Portland cement mortars, and it resists cracking.

This is the first in a 2-part series on shower and tub surrounds. This completes the preparation portion of the project. Please see the next article on installing the tile for this project.


Pingback from Tiling a Shower or Tub Surround | Welcome to Trevathan Floorcovering
Time January 30, 2010 at 5:43 pm

[...] In part 1, the preparations finished up with the application of Laticrete 9235. After the 9235 is completely dry, usually overnight, I start with the first row of tiles. Getting the first row level is extremely important since successive rows will sit on top. I did the back wall first so that the cuts in the corner are not as noticeable. After the first row is complete, I use a spacer board the appropriate width to allow for the glass and stone listello that will be installed later. The weight of the tile holds the boards in place. Be sure that the width of the board allows for the listello and a little bit of grout on either side. Making sure the boards are all the exact same width ensures that the tiles will stay level. [...]

Pingback from Sealing Hardi backer and glass block window – The Best Information & Resources for Flooring Products and Services
Time July 14, 2010 at 5:32 am

[...] doing (sans window). I used Permabase and Laticrete 9235, but otherwise the process is the same. Preparation for Tiling a Shower or Tub Surround | Welcome to Trevathan Floorcovering Tiling a Shower or Tub Surround | Welcome to Trevathan Floorcovering The top ten reasons to [...]

Pingback from Backer board and tub flange issue – The Best Information & Resources for Flooring Products and Services
Time August 18, 2010 at 12:18 pm

[...] the walls were framed a little too wide for the tub. I added strips and everything turned out okay. Preparation for Tiling a Shower or Tub Surround | Welcome to Trevathan Floorcovering The top ten reasons to procrastinate: [...]

Pingback from A TFP Flooring Forum Topic about: Tiling shower
Time October 5, 2011 at 11:58 pm

[...] if applicable in your case. Here's a similar example, only with a tub, but the idea is the same: Preparation for Tiling a Shower or Tub Surround | Welcome to Trevathan Floorcovering If I was setting a base like that, I would notch out the studs so that the lip was flush with [...]

Pingback from question on installing wall tile over painted surface, a discussion at The Floor Pro Community
Time April 21, 2012 at 9:28 am

[...] craft pretty well. Here's just one article, but check out some of the others while you're there: Preparation for Tiling a Shower or Tub Surround | Welcome to Trevathan Floorcovering [...]

Comment from david
Time January 24, 2013 at 11:49 am

that was a great article. thanks

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