Michal Mroczko | December 23, 2017

YouTube // Glues, Sealants, Coatings, Kitchens & Baths

It Takes 10 Minutes to Waterproof a Shampoo Niche #TheRightWay

Its waterproofing time.

"This is the most important part to waterproof because this is the place where all the water will end up and it might leak if not done correctly." 

Michal Mroczko


Editor's Note:

In the comments below, a lot of folks applaud Michal's niche waterproofing and vigorously question is use of drywall in a shower. It is not drywall, it is DensShield, a tile backer board made specifically for wet room applications, like showers. You can watch videos of Michal installing the DensShield here.


Shampoo niches are like windows: three-diimensional holes in walls that make water leaks much more difficult to stop. In the case of shampoo niches, there are some great fluid-applied waterproofing membranes available. Michal likes Laticrete over RedGuard because it has a more buttery texture and can be applied with a trowel.

He also stresses the importance of using the right tape. Mesh tape for drywall has large square holes in it, which are too big for the membrane to span with and seal.

"Sometimes you will see contractors applying RedGuard or this membrane (Laticrete) without any tape ...

Uh, just so you know, this membrane without a tape—eventually wider joints will crack. So the fiberglass tape is a must."

Step by step:

  • Use fiberglass tape, not drywall mesh tape. Fiberglass tape is for waterproofing. It will combine with the waterproofing membrane to form a shield against water. 
  • Precut the pieces of tape to wrap the walls, corners, bottom and top, and any other seams. Keep them handy, neatly laid on the floor.
    • 1 Bottom—cut about 2 inches wider than the bottom shelf.
    • 2 inside corner butterfly patches—cut about 1-1/2 inches square.
    • 4 transition strips to fold inside the corners (top and bottom) of the sides—cut in squares, the width of the sides.
    • 2 sides—cut about 2 inches wider than the side.
    • 1 top—cut about 2 inches wider than the top.
  • Apply membrane with a six-inch putty knife to the bottom of the niche, working the membrane into all the seams with the putty knife.
  • Apply membrane to the outside corners of the niche as well, working the membrane into the seams in the backer board.
  • Place the fiberglass tape with your hands and then apply membrane over it.
  • Start with the bottom. Michal makes a fold about an inch from one edge and uses it to form a clean crease along the front edge of the niche. The tape also folds up the back.
  • Apply butterfly patches to the corners These will overlap the floor and underlap the wall pieces.
  • A corner piece (cut to the width of the shelf) goes on top of the butterfly corner and is repeated on the other side.
  • The same process holds for the vertical corners in the back of the niche: Fold the long pieces into a Z-shape to wrap the outside and inside corners in a single strip.
  • Apply membrane over the tape, smoothing out any air bubbles. 
  • The top piece of tape goes in last, again, folding up over the outside corner and down over the inside corner. Waterproofing membrane is added over the tape. 
  • Also apply membrane over any uncovered backer board and screw heads.

Now, let it dry and it's ready to be tiled.


"And it won't leak—if you do it correctly."


Michal Mroczko is a tile contractor in Atlanta, GA who focuses on specialty bathrooms renovations. His YouTube channel has many good videos.



be a lot quicker and 100% waterproof if you use a kerdi niche.....

Check out the Wedi shower system quickest install and 1200percent water proof.

You should be ashamed of having a gypsum product on the top of your curb with twenty drywall screws in it. Even if you place a membrane over it, there's still a huge risk of the screws rusting, the gypsum becoming mush, and the curb rotting.   Your pan also has no preslope under the chlorlaychlorloy liner which is both necessary and required. That shower floor will constantly be wet because there is nowhere for the water that get through the grout lines to exit .



With the many beneficial products today, utilize a presloped laticrete (or similar) pan. Mud pans are out dated and time consuming. Not to mention, the use of liners below the shower pan are way too often done wrong. Our county has enforced pan inspections due to do many contractors installing them wrong. As far as the actual topic of Niche install, this is a nice detail. You can use regular Alkaline tape on seams and approved mortar, followed by a coat of Hydroban or RedGaurd, but it's more time consuming. The use of the 6" tape embedded into the Hydroban is most efficient. Bottom line: nice niche but the pan would fail pan inspection based on above comment and what appears to be screws in the pan liner.

Though the niche waterproofing is commendable, it appears the entire substrate is regular drywall, which is a HUGE red flag.  Why not use a cement based backer board?

We only us Durock on shower walls. Just last week, we demoed a shower built in 2004. Tile was on a gypsum product 

and the entire block wall behind tile was soaked.


why would anyone utilize drywall in a shower. We would always use a preform niche (which the average cost is 50.00) into a 5/8" dura-rock then seal all seams then install the tile in niche and walls


I would strongly suggest that you consider consulting with a waterproofing expert and a prominent construction defects litigator.   IF you are a licensed contractor and you build like this in CA, you will surely be sued for construction defects shortly after any issues are discovered.  Drywall of any kind is NOT an considered an acceptable tile backing by the American Tile Institute.  Although the majority of builders will now use cementatious tile backer board (i.e. Hardibacker, etc.) for showers (although the best solution is a cement float installation for tile backer), the last time I checked even this with a proper moisture barrier is NOT acceptable by the Amerian Tile Institute.  The ATI would be one of the first to be called in by a Construction Defect Litigator in the process of going after a contractor using any method which is not considered optimum.  But using drywall (regardless if it is exterior or waterproof rated) is simply not an acceptable nor professional method for a tile shower.  I would strongly suggest that you re-do this video using at least an approved cementatious tile backer board, and then demonstrate how to waterproof the corners.   But you should also start at the beginning, as your video does not even mention that there is an approved moisture barrier behind the backer board, which is also required.   Good luck.... 

Daniel Morrison's picture

Guys, it is not drywall, it is DensShield. 

I added a link at the top of the page to a video of him doing the wall board and explaining his process.

Thanks for the comments and please post your own videos and articles to ProTradeCraft.




ThanksHow do I go about fixing the niches that are already tiled and leaking?  I really am not ready to redo the whole bath.  I had thought about ordering prefab inserts and installing over existing tile. Problem nothing is standard size.  Tried sealing edges with caulk like product that contractor recommended but that isn't working. I need to do something or I will be forced to do gut job.


Amazing how many people bash this video and the instructions therein without really understanding the product he's using. Denshield has the highest moisture/mold proof ratings in the industry10 out of 10. No, I don't work for Densshield or GP. Do you homework or listen/read before commenting. BTW, this TileMasterGa has probably the best tile videos on youtube. He's a true professional who doesn't cut corners! 

Daniel Morrison's picture

Well, thanks for the comment and the support, Straightgrain. I agree about TileMasterGA being a to-notch tile guy. I like his videos. 

I have to admit, I was skeptical of DensShield when I first saw it—but that was almost 20 years ago. I guess it works it's way to different places at different paces.


So, the white tape he's using is a fiberglass product? What about using Redgard or Kerdi band seam tape with thin set on the seams and corners on the Denshield instead of this particular fluid based waterproofing installation?  Thanks

Daniel Morrison's picture

His main point on the tape is to avoid the fiberglass mesh tape that is used on the wallboard seams. It is the wrong kind for waterproofing the shower niche.

The tape he is using is compatible with the membrane he paints over it. He is using Laticrete membrane.

If using RedGuard membrane, use RedGuard tape. If using Kerdi membrane, use Kerdi tape. 

Make sure the tape and the membrane are compatible.


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