Always.
It's a shower. It needs to be waterproof.
A product I've used and liked is RedGard:
You install your backer board, then 'paint' this on. It's basically an adhesive roll-on rubber membrane. You then tile right on top of it.
I like this better than the traditional plastic-behind-the-backer-board for two reasons 1) You can easily put holes in the plastic during construction (screw holes, for instance) and 2) the RedGard is closer to the 'wet side' of the wall, reducing the chances of water getting into the wall.
Answer from DA01 on Stack ExchangeThe Home Depot
homedepot.com › flooring › flooring supplies › surface prep › underlayment
Tile - Waterproofing membrane - Underlayment - The Home Depot
Get free shipping on qualified Waterproofing membrane, Tile Underlayment products or Buy Online Pick Up in Store today in the Flooring Department.
The Tile Shop
tileshop.com › shop › waterproofing-membranes
Waterproofing Membranes
Superior Pro-Shield Membrane - 3 ft. 3 in. x 33 ft. ... The Superior Pro-Shield Shower System contains all the pieces and accessories you need to fully waterproof and prepare a...
Tiling shower... is a waterproof membrane necessary?
Finally something I can answer! I have worked in pool and medium-large bathtub construction and installation for the last 5 years, so I might be able to give a bit of insight. So, the answer to this one is that he is half right. Using a waterproof membrane is like wearing a condom, if you know how to pull out properly you don't need it, but if you try to get by without one and fuck up, you have 18 years of child support payments waiting for you. Similarly, there are definitely ways of water proofing without resorting to a membrane, but if this is your first time, its probably safer to use one. However, if you do decide to go without, make sure to both thinset AND tape vulnerable points, but make sure to also cross tape a few times to keep moisture from loosening the adhesive. That being said, beware of over-proofing the base if you go with the membrane option. If you are using a membrane with a DG or DG- rating, you should under no circumstances double proof, like you would with say a P-k rating or higher. This is because the porosity of the clay based polymers is variable among membranes (hence the DAR rating) and is also variable to an extent within production batches, which is why it's always recommended you do a copper-phosphorous drain test before applying. As long as you use the old "DG thin on me, R/P(i,k) lay it on thick" saying, you pretty much can't go wrong. Tl;dr either way could work, but a condom is better for virgins. EDIT: misspelled porosity, thanks u/198jazzy349 More on reddit.com
109
426
August 9, 2016walls - When should a waterproof membrane be installed for shower tiling? - Home Improvement Stack Exchange
For what kinds of wall structure - tile type combinations a waterproof membrane should be used between walls and tiles? More on diy.stackexchange.com
Opinions on liquid water proofing vs water proofing membranes
Tile coach has some pretty great videos where he tests the waterproofness of foam board vs membrane and membrane wins (albeit, marginally). The membrane waterproofing is thicker than the felt that comes preinstalled on the kerdi board. With all the requisite seam/corner/screw taping, I feel great peace of mind using membrane over concrete board, and it’s cheaper. However, for the ease of installation and ability to wet shim, kerdi board is a great option, it’s just very $$. For professionals who are trying to move quickly and save time, I think foam board is a great option. However for a DIY bathroom, you’re going to be going slow anyways, so why not save your money and get the best shot at waterproofing correctly (I emphasize correctly because there is a lot of room for error while installing your own membrane, so do your research). Remember, get the air bubbles out with a drywall knife, but don’t push all the thinset out, have the right trowel size, and overlap seams by 2”! More on reddit.com
32
5
October 24, 2023Thinset for waterproofing membrane seals?
Hope you get some answers as I am also curious More on reddit.com
10
6
April 26, 2025What are the shipping options for Waterproofing membrane Underlayment?
All Waterproofing membrane Underlayment can be shipped to you at home.
homedepot.com
homedepot.com › flooring › flooring supplies › surface prep › underlayment
Tile - Waterproofing membrane - Underlayment - The Home Depot
Are there any special values on Waterproofing membrane Underlayment?
There are over 5 special value prices on Waterproofing membrane Underlayment.
homedepot.com
homedepot.com › flooring › flooring supplies › surface prep › underlayment
Tile - Waterproofing membrane - Underlayment - The Home Depot
What are some of the most reviewed products in Waterproofing membrane Underlayment?
Some of the most reviewed products in Waterproofing membrane Underlayment are the Schluter Kerdi-Band 5 in. x 16 ft. 5 in. Waterproofing Strip with 92 reviews, and the Schluter Kerdi 3 ft. 3 in. x 16 ft. 5 in. Waterproofing Membrane with 91 reviews.
homedepot.com
homedepot.com › flooring › flooring supplies › surface prep › underlayment
Tile - Waterproofing membrane - Underlayment - The Home Depot
Videos
25:47
Which Tile Membrane Installs Faster and Easier? - YouTube
11:40
Foolproof Waterproofing for a Tile Shower | Liquid Membrane - YouTube
11:47
Waterproofing a Shower Floor - YouTube
How to Install a Waterproofing Membrane in a Tile Shower
04:16
Creating a Curbless Waterproof Shower | This Old House - YouTube
19:38
Which Liquid Membrane is BEST??? —Testing HydroBan vs. RedGard vs.
LATICRETE
laticrete.com › products › 9235-waterproofing-membrane
9235 Waterproofing Membrane
An easy-to-install, thin, load-bearing waterproofing membrane designed specifically for the special requirements of ceramic tile, stone, and brick installations.
Amazon
amazon.com › Waterproof-Membrane-Flooring-Underlayment-Ceramics › dp › B08NDKTSHM
108 SQ FT Waterproofing Membrane for Bathroom Shower, 27.6mil, 3' 3" x 32.8FT Tile Flooring Underlayment Roll Under Ceramics, Natural Stone Tiles and LVT for Shower Wall, Bathroom Floors - Amazon.com
UCANVIN Waterproofing Membrane Band Roll, 30Mils Thick, 5Inch X 98.5Ft Tile Floor Underlayment Waterproofing Polyethylene Fabric Waterproof Membrane for Tiles, Shower Walls, Bathroom Floors
Remedial Membranes
remedialmembranes.com
Clear Waterproofing Membrane, Over-Tile Membrane.
Remedial Membranes, Clear Waterproofing Membrane is designed to waterproof on top of tiles to fix leaky balconies and shower floors without tile removal.
Reddit
reddit.com › r/diy › tiling shower... is a waterproof membrane necessary?
r/DIY on Reddit: Tiling shower... is a waterproof membrane necessary?
August 9, 2016 -
We gutted our bathroom and installed a steel tub. Our plan is to use 12x12 porcelain tiles from the tub to the ceiling. We already installed hardy board and are ready to proceed but we have gotten mixed advice.
In the old shower, we had some grout problems and water found its way through and damaged the floor and the first floor ceiling (underneath the tub). This time around, we don't want to cut any corners with waterproofing. We planned on using thinset and/or tape on all the hardy board joints, screws, etc, and then coating everything with a membrane such as Red Guard, Ardex 8+9, etc). However a contractor we know and a local tile store told us these waterproof membranes are totally unnecessary if we do things correctly. They said thinset itself is sufficient to waterproof anything.
I feel like I should trust this advice but I just can't help but think we will inevitably have a problem, even if it is years down the line, and I will regret not going with a membrane as an extra layer of protection.
Thoughts? Any disadvantages to overdoing the waterproofing?
Top answer 1 of 5
33
Finally something I can answer! I have worked in pool and medium-large bathtub construction and installation for the last 5 years, so I might be able to give a bit of insight. So, the answer to this one is that he is half right. Using a waterproof membrane is like wearing a condom, if you know how to pull out properly you don't need it, but if you try to get by without one and fuck up, you have 18 years of child support payments waiting for you. Similarly, there are definitely ways of water proofing without resorting to a membrane, but if this is your first time, its probably safer to use one. However, if you do decide to go without, make sure to both thinset AND tape vulnerable points, but make sure to also cross tape a few times to keep moisture from loosening the adhesive. That being said, beware of over-proofing the base if you go with the membrane option. If you are using a membrane with a DG or DG- rating, you should under no circumstances double proof, like you would with say a P-k rating or higher. This is because the porosity of the clay based polymers is variable among membranes (hence the DAR rating) and is also variable to an extent within production batches, which is why it's always recommended you do a copper-phosphorous drain test before applying. As long as you use the old "DG thin on me, R/P(i,k) lay it on thick" saying, you pretty much can't go wrong. Tl;dr either way could work, but a condom is better for virgins. EDIT: misspelled porosity, thanks u/198jazzy349
2 of 5
20
It depends on what you are using for your tile board. If you use Durarock or another cementitious board, then you should use a waterproofing membrane. However, some boards, like Diamondback have a built in moisture barrier and don't need an additional membrane. Your best bet is to read the manufacturer's product data and do what they recommend. Source: I'm a commercial construction general contractor
TEC
tecspecialty.com › products › surface-preparation › hydraflex-waterproofing-crack-isolation-membrane
HydraFlex Waterproofing Crack Isolation Membrane & Waterproofing Membrane | TEC
HydraFlex™ Waterproofing Crack Isolation Membrane is a ready-to-use, flexible, mold and mildew resistant waterproofing crack isolation membrane for interior and exterior applications. It forms a smooth, monolithic, watertight surface over walls, floors and ceilings.
Top answer 1 of 3
6
Always.
It's a shower. It needs to be waterproof.
A product I've used and liked is RedGard:
You install your backer board, then 'paint' this on. It's basically an adhesive roll-on rubber membrane. You then tile right on top of it.
I like this better than the traditional plastic-behind-the-backer-board for two reasons 1) You can easily put holes in the plastic during construction (screw holes, for instance) and 2) the RedGard is closer to the 'wet side' of the wall, reducing the chances of water getting into the wall.
2 of 3
2
As DA01 said Always use wetseal, considering how much it costs it is a worth while investment
- Install the wall sheeting (we usually use villa-board which is a cement fibre board)
- Set the joints on the wall sheeting, fill any gaps between the wall and floor with silicon
- After all the sheets are set and dry
- Apply 1 coat of wetseal, for bathrooms in my state we seal the whole bathroom floor and up the wall 150mm where there is no splash areas and up the wall to a min of 2m in the shower
- Use a fibre wetseal joint tape in all corners eg where the wall and floor meet and where walls meet, this should be install why wetseal is still wet and then wetseal should be re -applied to just the wetseal tape.
- After 24hrs and wetseal is dry reapply another coat over all the area you have already covered
You can also get a professional to do this for you. Having a good wet seal job is very important for the longevity of your bathroom
Contractors Direct
contractorsdirect.com › home › waterproofing membranes & uncoupling membranes
Waterproofing Membrane | Contractors Direct
Waterproofing is critical in areas like bathrooms and kitchens. Preventing water from seeping through the tiles and causing damage to the underlying structure. Contractors Direct offers a wide range of top-rated waterproof sheet and liquid membranes from trusted brands like Schluter, Laticrete, and Mapei.
Sika
usa.sika.com › floor covering installation › tile & stone installation › waterproofing
Waterproofing
Composed of low VOC modified elastomeric copolymers, Sika waterproofing membrane systems are uniquely engineered to deliver waterproofing, crack-isolation, and vapor-control solutions, addressing the demands of wet and high-moisture environments encountered in today’s ceramic tile and stone installations.
Bunnings Workshop
workshop.bunnings.com.au › t5 › Bathroom-and-Laundry › How-to-repair-damaged-waterproof-membrane › td-p › 101117
How to repair damaged waterproof membran... | Bunnings Workshop community
March 29, 2022 - I have remove the broken tile by myself without damage the good tile. I need guardian to do what I can to fix my shower room. Please advice . Thanks ... That's disappointing to hear, @joyceL. The issue is that a shower membrane is a continuous coating applied over the base of your shower and then up the walls. Hopefully, you shouldn't need to do the whole bathroom if your shower has a hob, but I'd suggest most waterproofers will want to redo at least the shower recess to be confident in warranting their work.
ProLux Materials
proluxmaterials.com › prolux materials › collections › tile waterproofing systems
Tile Waterproofing Systems for Sale ☑️ Best Prices
September 26, 2025 - Whether you are upgrading a shower or sealing a kitchen floor, these solutions simplify waterproofing tile projects with consistent results. ... PROVA Mat Waterproofing Membrane is a thin, flexible, low-perm sheet membrane that creates a watertight ...
TikTok
tiktok.com › @cptant3 › photo › 7570826999686515998
From the studs to start of waterproofing membrane ...
We cannot provide a description for this page right now
AMES Research Laboratories
amesresearch.com › home › all products › shop all › blue max® tile & floor
Blue Max Tile & Floor | Waterproof Tile & Floors | AMES
Very happy with this product.
Blue Max® Waterproofing & Crack Prevention Tile & Floor Membrane is a tough, blue, elastomeric, liquid rubber for the application of floor and wall tiles. I made the change to Blue Max for bathroom tile installations, and I am so glad I did!
Schluter
schluter.com › waterproofing membrane for a shower
Waterproofing Membrane For A Shower | Schluter
KERDI is part of the Schluter®-Shower System, an integrated family of products that that together form a fully bonded, watertight assembly for tiled showers. In addition to this sheet-applied membrane, Schluter offers a suite of KERDI accessories that facilitate the waterproofing of tiled floors and walls, including pipe seals, preformed corners, and waterproofing strips.
Mapei
mapei.com › home page › training › "tech talk" blog › detail
A Beginner’s Guide to Waterproofing Membrane and Shower Floor & Tile Installation with LVT | Mapei
A waterproofing sheet membrane such as the Mapeguard WP 200 is designed to be installed on the surface of the tile backer board and shower base, using either a thin-set mortar or self-adhesive “peel-and-stick” technology.
Quora
quora.com › Can-the-waterproofing-of-bathrooms-be-done-on-already-fitted-tiles
Can the waterproofing of bathrooms be done on already fitted tiles? - Quora
Answer: The major source of leakages in the building is the bathrooms/toilets. Proper care should be taken while the bathroom is in the making itself. Now a days PVC pipes are majorly used for piping, SWR line, and the adhesion of PVC is not so good with cement. Proper care should be taken for th...
Reddit
reddit.com › r/tile › opinions on liquid water proofing vs water proofing membranes
r/Tile on Reddit: Opinions on liquid water proofing vs water proofing membranes
October 24, 2023 -
Hello,
I’m just curious if there are perceived pros and cons between using liquid waterproofing and water proof membranes. My first impression is that liquid water proofing seems easier to apply and also eliminates any concerns with seams between membrane sheets. On the other hand, membranes eliminate the possibility of pin holes in the water proofing that could occur with liquid water proofing. Do you guys have more experience with each of them. Which do you prefer?
Top answer 1 of 5
4
Tile coach has some pretty great videos where he tests the waterproofness of foam board vs membrane and membrane wins (albeit, marginally). The membrane waterproofing is thicker than the felt that comes preinstalled on the kerdi board. With all the requisite seam/corner/screw taping, I feel great peace of mind using membrane over concrete board, and it’s cheaper. However, for the ease of installation and ability to wet shim, kerdi board is a great option, it’s just very $$. For professionals who are trying to move quickly and save time, I think foam board is a great option. However for a DIY bathroom, you’re going to be going slow anyways, so why not save your money and get the best shot at waterproofing correctly (I emphasize correctly because there is a lot of room for error while installing your own membrane, so do your research). Remember, get the air bubbles out with a drywall knife, but don’t push all the thinset out, have the right trowel size, and overlap seams by 2”!
2 of 5
3
Neither. Personally I use kerdi board most of the time. I'd try another brand if it was easier for me to get. I love that I can wet shim the boards. I love that I can carry an entire shower's worth of wall board in one load. I can cut them with no mess. Etc etc. Overall just a huge step up from cement board.
Tools4Flooring
tools4flooring.com › home › underlayment & cushion
Tile & Stone Membranes | Tools4Flooring.com
Ardex UI 720 Flexbone Floating Tile Underlayment, 215 SF Roll ... Due to local regulations, this product is restricted from sale to your current shipping address.Close tooltip · NAC NS97 1 Gal. Exterior Primer ... Due to local regulations, this product is restricted from sale to your current shipping address.Close tooltip · Noble Deck Exterior Thin-Bed Waterproofing Membrane - 6 ft.