Jason Cousineau Solutions Inc.

No-caulk tiling method for showers and tub surrounds

(Written November 25, 2025 by Jason Cousineau)

In the majority of tiled showers and tub surrounds, the corners are caulked.  The caulk tends to get moldy over time, and occasionally shrinks and cracks.  The caulk can't be scrubbed vigorously, and, once moldy the caulk may be permanently stained. If grout is used instead of (or underneath) caulk in a corner, it often cracks as the corner bears the brunt of lateral forces from the wall's expansion and contraction.

The following is a method to tile showers and tub surrounds in a way that doesn't require caulk, and doesn't crack.  This method has been tried and proven, resulting in corners that look like new 10+ years later.

Warning: It is more difficult and expensive than traditional methods. It is significantly more time-consuming.

Requirements:

To complete this project, you’ll need the following:

• Wall access down to the studs of wall behind the area to be tiled.

The wall (corners in particular) will likely need to be reinforced.

• Acrylic grout

Mapei Flexcolor CQ or Fusion Pro are common examples.  Acrylic grout comes pre-mixed in sealed buckets.  Epoxy grout may also work.  Do not use cement grouts for this.   Acrylic grout is used because it's more flexible and adheres better than traditional grout, as well as being chemical-resistant, scrubbable, and stain-proof.

• Tile edging (aluminum or PVC) in a colour that complements the tile and grout.

For every linear foot that would be normally be caulked, you will need a foot of tile edging instead.  PVC is much faster and easier to work with.

• Materials, Tools, and Skills

-You need to be able to frame and/or reinforce the wall behind the tub or shower.

-You need to be able to build a proper waterproof shower surround. This tiling method has been tested with Kerdi (Schluter) and Wedi tile systems.  

-You need to be able to tile and use Acrylic grout.  Acrylic grout is considered more difficult to use because of a much-shorter working time.  Also, Acrylic grout generally requires 72 hours of curing time before water exposure.

Getting Started:

The critical thing to get right with this is the corners.  In a typical shower, the corners are the place where the most movement, stretching, and flexing takes place.  To eliminate the need for caulk, the corners must become the most rigid part of the shower (rather than the least).  

Every situation will be different, but the goal is to get those corners as strong as possible.  Add more wood and add more fasteners.  Ideally construction adhesive is used on the wood the corner is to be assembled from, followed by nails to get the wood as tightly bonded as possible, followed by #10 screws (pre-drill or self-tapping) to keep the wood as tightly bonded as possible.  At the end of the day, every corner should feel as firm as the trunk of a large maple tree.

Once your corners (all of them that will support a tiled surface) are good, proceed to use Kerdi, Wedi, or whatever you wish to build the waterproof surround to be tiled.

The firm corners will redirect the expansion and compression forces to the tiled wall surfaces.  The wall surfaces will be able to handle this stress better as there is a much greater distance across which to spread the force, combined with the flexible nature of the acrylic grout and of tile edging.

Tiling

The tiling method used here is best described as "overlapping slabs." It requires a bit of planning.

Slabs at the "lowest level" are overlapped by other slabs at every edge and do not overlap any other slabs. These slabs get no tile edging at all. Slabs at the highest level are not overlapped by any other slab. These slabs get tile edging on every edge. Some slabs are at intermediate levels and will get tile edging on edges that are not to be overlapped by other slabs.

The "lowest level" slabs go in much like a floating floor, where a small gap exists between the tile and the wall. The gap must be less than the depth of the tiles used. This gap can be filled or partially filled with mortar or acrylic grout. It allows the underlying wall to contract without risking tiles popping off—similar to how the gap between a floating floor and wall prevents folding and buckling in humid conditions.

In the following pictures, the "lowest level" slabs are the ones at the back of the niches. These are mortared on first. The shower floor (not shown) is also a "lowest level" slab.

The walls of the niche are tiled next, as shown in the pictures below:

First, add the bottom and top slabs.

Then, add the two side slabs.

Here, aluminum tile edging has been cut to frame the sections. The bottom and top slabs get edging at the front and back, but not on the left and right, as those areas will be covered and overlapped by the side slabs. It's much easier to use PVC edging for this, as it can be cut with a utility knife. The edging gives a clean look and allows for a gap for grout on both planes. The grout-filled gap is important to allow for expansion and contraction.

Below: The niche with grout added.

With the floor, the niches, and the back wall installed, the left and right sides of the shower go on next, as shown in the following pictures. These are highest-level slabs, as they overlap the floor, back wall, and ceiling.

The result is an aesthetically-clean, washable, long-lasting, caulk-free shower surround.

The following two pictures show tub surrounds done using this method with PVC tile edging. Note that grout should not be used to transition between the tile and tub, as tubs lack stability, and the grout cannot be expected to adhere to the tub material amid expansion, contraction, and vibration. In these examples, sealants consistent with manufacturer recommendations were used.

Below: Two completed surrounds using this method with aluminum tile edging.

This writeup is free to use, modify, and share. 

It is intended to demonstrate a tiling method only.  It assumes all necessary steps have been taken to ensure a solid, leak-free shower or tub. The tiling method is not intended to produce a waterproof surface or be used as primary waterproofing. In all cases, work should comply with applicable building codes and manufacturer recommendations.

Questions, comments, complaints, and improvements are welcome.  

[Contact Us]