[ 05 Steps] How to Waterproof Your Bathroom Walls?

A bathroom is a higher water-consuming area in the home. So most water leaking problems can occur due to this. Hence it is essential to waterproof it properly. During the waterproofing process, you have to waterproof walls, and floors step by step. I will share my experience with you quickly. So let’s see how to waterproof your bathroom walls easily using these 05 steps.

I will guide you to waterproofing the walls in the bathroom. Considering construction, we meet two main types of walls and floors.

  • Concrete slab – Brick walls,
  • Concrete slab – wood wall.

These are the main types of wall construction we can meet. Here I have separately discussed each waterproofing method separately for waterproofing the bathroom walls.

Step 01 – Measure, Sketch and Prepare a Plan

Sketch for the waterproofing
Sketch for the waterproofing

We need to measure and plan everything for both wall types. You can waterproof your bathroom within 08 steps using this guide.

Here we must know how much amount of waterproofing will need and what are instruments we have to use. And also if we need to place any object like a bathtub later we must plan where we have to put it. 

You can check the lines of the walls and if their proper supports are available for the wood wall. By having all detail, you can plan your work with the proper materials.

Step 02 – Select the Waterproofing Method

Waterproofing methods are an important selection. According to the site condition and clients’ requirements, you should select the what is the suitable waterproofing method you can use.

There are so many methods to be used with so many products. But select the best one which is suitable.

When you select the suitable method and product, you must select all sub-products related to that. Else those will not compatible with each other. “ Wedi” is one of the best products I saw with many sub-products. And also, you should follow the method statement as much as possible for the best result. You can use the below methods for the concrete slab – brick walls and Concrete slab wood-based walls.


Concrete Slab – Brick Walls Waterproofing Methods

  • Bituminous waterproofing membranes
  • Cementitious waterproofing method
  • Sheet membrane methods


Concrete Slab – Wood-Based Wall Waterproofing Methods

  • PVC sheet membranes
  • Prime coat with a bonding agent
  • Waterproof wall panels

Read More About – How to Do Wood Waterproofing?

Step 03 – Clean and Clear the Area

Before starting the waterproofing method, cleaning is essential. Sometimes the surface is leaking, and biological growth can happen. At this time, you need to use suitable ways to remove them and sometimes wall panels may be damaged. And plastering can be damaged. So before you start the waterproofing, cleaning and clearing is essential. 

If the wall is cracked use the silicon-based sealant that your selected product. And check the strength of the wood supports. If you don’t have proper support for the walls, take action to build it. If you are unable to prepare the correct surface, the waterproofing can be failed.

Step 04 – Apply the Bonding Agents

Bonding agent for waterproofing
Bonding agent for waterproofing

After you finish the cleaning, seal all edges and cracks using silicone sealant in your selected product.

After preparing the surface, you need to apply the bonding agent. We called these primes. These agents make proper bondings between surface and waterproofing. Before applying the bonding agent, clean the surface if you can wash and dry, it is very good. Sometimes small dust will cause debonding.

You can use a brush, roll a brush, or sprayer to apply the primer onto the surface.

Step 05 – Apply the Waterproofing

How to Waterproof Brick Wall in Bathroom?

Here we have well-bonded edges and corners. But we can’t assure water will not leak. For a better way, you have to seal all the edges and corners according to your selected method. Edges must be filled with the used waterproofing material walls, and slab connection edge can be highly leakage as well as corners of the walls and slab. You had better use fiber mesh and bonding agent for this. It is enough 2” for the wall and 2” for slab lapping distance.

  • After corners and edges are well sealed, apply the first coat of the main coat and then once it is dry, apply the second coat.
  • When you waterproof the walls, you do not need the apply waterproofing to all walls. It is enough if you can apply the height of the shower to 8’ and the conical shape to 3’ per side from the shower from top to bottom. This is the area we can assume that water is always flowing. And considering the opposite walls, it should be done the area like that.
  • And the side walls also can be waterproof like that if the shower is in the corner of the room. Gully hole and commode fixing nuts are also placed before the waterproofing. And those should be well covered with waterproofing. 

Concrete Slab – Wood walls

  • First of all you need to use a sealant for seal the edges. After edges and corners are sealed using the primers of your product. Primers are essential for the bonding process. 
  • When the priming is done, use the fabric for the edges and corners with bondings agents
  • Then apply the first coat of the waterproofing and apply the second coating.
  • More than that, you can use PVC membrane, Bituminiuos coatings, and many more. Some are expensive and durable; some are cheap and have a short lifetime.
  • There are some wall panels that are made as waterproof. So if you use this kind of panel, make sure to cover each and every place you drill. These panels are easily fixed, and it surface is designed for the best adhesiveness of the bonding agents.
Apply waterproofing
Apply waterproof

Step 06 – Protect the Layers

This is really important after you finish the waterproofing walls. Because applied layers can be damaged due to further construction processes such as cutting, drilling, and any masonry task, so you should protect it every time as much as possible.


Owner Randy Organ

Randy Organ

I am Randy Organ, a researcher as well as 10 years experienced technician for home construction. My hobby is studying new problems and seek well technical and modern solutions. Water is an invaluable resource. But it hurt much more to many more industries. Structures and electrical are a few of them. Here I try to find ways and solutions for the water leaking