How to Waterproof Bathroom Floor? Method, Products, Cost, and Time

Adam-Paul
Written By Adam Paul - Waterproofing Expert

Bathroom floor waterproofing is a process of laying a waterproofing membrane on the top of the bathroom floor before tiling. Bathroom floor waterproofing is a step-by-step process that you should follow properly. 

How to waterproof the bathroom floor?

  1. Clean the bathroom floor.
  2. Apply Primer on the bathroom floor.
  3. Cut the Membrane according to the bathroom floor width and length
  4. Apply Adhesive for sheet membranes on the bathroom floor
  5. Lay the Membrane on the bathroom floor 
  6. Seal the Joints in the sheet membrane on the bathroom floor
  7. Seal Edges in the bathroom floor
  8. Let the waterproof membrane Dry 
  9. Check for bathroom floor Leaks
  10. Install Flooring on the bathroom floor

Before waterproofing the bathroom floor, you should have tools such as waterproofing membrane, primer, fiberglass mesh tape, sealants, silicone caulk, grouts, trowel, roller, brush, and leveling instrument. You should always use the recommended products by the manufacturer for a durable waterproof membrane.

Bathroom floor Waterproofing

When you waterproof your bathroom floor, you must spend $750 to $2000. It will take 1-2 days to waterproof a bathroom floor if you are a professional, skilled waterproofing expert. If you are a DIY enthusiast, you have to spend 2-3 days waterproofing the bathroom floor. When you waterproof the bathroom floor, you should waterproof the bathroom walls also.

What Materials and Tools are Needed for Bathroom Floor Waterproofing?

You can use the below material and tools for bathroom floor waterproofing. Each of these materials is used for specific tasks in the bathroom floor waterproofing steps. You should have all of the tools before starting the bathroom floor waterproofing.

  1. Waterproofing Membrane: You can use sheet membranes and liquid membranes for bathroom floor waterproofing. You can use PVC and bituminous waterproofing membranes as sheet membranes while you can use cementitious waterproofing and acrylic waterproofing as liquid waterproofing membranes for the bathroom floor.
  2. Primer: Primer is used to enhance adhesion between the membrane and the bathroom floor substrate.
  3. Fiberglass Mesh Tape: Fiberglass mesh tape is used in bathroom floor waterproofing to reinforce seams and joints in the substrate.
  4. Silicone or polyurethane waterproof sealants: Silicone or polyurethane sealants are applied to joints, corners, and edges to provide an extra layer of protection against water penetration to the bathroom floor.
  5. Silicone caulk: Silicone caulk is used to seal gaps and joints, on the bathroom floor, especially around fixtures like sinks and bathtubs. 
  6. Waterproof Grout: Waterproof grout is important to prevent water from seeping through the grout lines and causing damage on the bathroom floor.
  7. Trowel, Roller and Brushes: A trowel is used for spreading the waterproofing membrane on the floor, while a roller helps ensure proper adhesion and remove air bubbles. Brushes are essential for applying the liquid waterproofing membrane on the bathroom floor.
  8. Leveling Compound: In case the bathroom floor has uneven areas, a leveling compound may be needed to create a smooth and flat floor before applying the waterproofing membrane.

How to Waterproof Bathroom Floor?

Bathroom-Floor-Waterproofing-steps

You can waterproof the bathroom floor by following the below 10 steps. You can use the materials and tools mentioned above.

  1. Clean the bathroom floor: Start bathroom floor waterproofing by removing any dirt, dust, debris, or any oil marks on the surface. After cleaning, let the bathroom floor surface dry.
  2. Apply primer on the bathroom floor: You should apply the primer on the bathroom floor. Primer helps to improve the adhesion between the waterproofing membrane and substrate properly.
  3. Cut the membrane according to the bathroom floor width and length: If you use sheet membrane on the bathroom floor waterproofing, you should cut waterproofing membrane similar to the measured distances. You had better keep the recommended space for joints and seams. 
  4. Apply adhesive for sheet membranes on the bathroom floor: You should apply the adhesive on the bathroom floor if you lay the sheet membrane on the bathroom floor. 
  5. Lay the membrane on the bathroom floor. 
    • If you use sheet membrane waterproofing on the bathroom floor, you can lay the waterproofing membrane onto the adhesive while it is still wet. Do not let the air bubbles to included in the waterproofing layer. 
    • If you use a liquid waterproof membrane, you can apply the coating on the floor by using a spray, brush or roller. 
  6. Seal the joints in the sheet membrane on the bathroom floor: You should seal the joints and seams on the waterproofing membrane on the floor using a waterproof tape that is recommended by the manufacturer.
  7. Seal edges in the bathroom floor: You should Use a silicone sealant to seal the edges where the floor meets the walls, around the toilet base, or any other fixtures that are bolted to the floor.
  8. Let the waterproof membrane dry: After applying the waterproofing membrane, you should keep it for drying as per the manufacturer's recommendation. During this time, do not expose the bathroom floor for water.
  9. Check for bathroom floor leaks: After the bathroom floor is dry, check for any potential leaks. Pay special attention to the seams and edges.
  10. Install flooring on the bathroom floor: Once the waterproofing layer is completely dry and secure, you can install your desired flooring on top. You can use waterproof grout for grout line waterproofing. It improves the waterproofing capacity of the bathroom floor.

Can I Waterproof the Bathroom Floor Without Removing Tiles?

Yes, you can waterproof the bathroom floor without removing tiles. First, you should use a waterproof grout for grout line sealing. Then, you can use waterproof paint, sealers, or epoxy coating on the tile floor. These membranes can prevent the water from leaking through the tile floor.

Epoxy for bathroom Tile Waterproofing

What Products Can Be Used for Bathroom Floor Waterproofing?

You can use the material and tool product below for bathroom floor waterproofing. These brands are the most popular brands for waterproofing tasks. 

Sheet membrane waterproofing products for bathroom floor waterproofing

  1. Schluter-KERDI
  2. NobleSeal CIS
  3. RedGard Waterproofing
  4. Crack Prevention Membrane

Liquid membrane waterproofing products for bathroom floor waterproofing

  1. Laticrete Hydro Ban
  2. Mapei Mapelastic AquaDefense
  3. Custom Building Products 
  4. RedGard Waterproofing 

Primer products for bathroom floor waterproofing

  1. Aqua Mix Sealer's Choice Gold
  2. Mapei Eco Prim Grip

Fiberglass mesh tape products for bathroom floor waterproofing

  1. USG Sheetrock Fiberglass Joint Tape
  2. Saint-Gobain ADFORS FibaTape.

Waterproof sealants for bathroom floor waterproofing

  1. GE Silicone II Kitchen and Bath Caulk
  2. DAP 3.0 Advanced Self-Leveling Concrete Sealant

Caulk waterproofing products for bathroom floor waterproofing

  1. GE Silicone II Kitchen and Bath Caulk
  2. Loctite Polyseamseal Tub and Tile Sealant.

Waterproof grout for bathroom floor waterproofing

  1. Custom Building Products 
  2. Fusion Pro Single Component Grout
  3. Mapei Flexcolor CQ Grout

Towels, roller, and paint brush products for bathroom waterproofing

  1. Purdy White Dove Roller Cover
  2. Marshalltown Notched Trowel
  3. Wooster Brush Epoxy Glide Roller

How Much Does It Cost to Waterproof Bathroom Floor?

The average cost for waterproofing 6 × 10 feet bathroom floor is between $750 to $2000, including surface preparation, materials, waterproofing membranes, and labor. The cost of bathroom waterproofing may vary with the material quality, waterproofing floor size, surface preparation effort, type of waterproofing method, labor rate, and installer's skill. 

How Long Does It Take to Waterproof a Bathroom Floor?

It will take 1-2 days to waterproof a bathroom floor if you are a professional, skilled waterproofing expert. If you are a DIY enthusiast, you have to spend 2-3 days waterproofing the bathroom floor. 

The time of the bathroom floor waterproofing depends on the size of the bathroom floor, the types of materials you use, the current condition of the bathroom floor, and the weather conditions of the environment. The bottleneck of the bathroom floor waterproofing is curing time. You have to stay until the surface is getting dry. 

Should I Waterproof the Bathroom Walls?

Yes, You should waterproof the bathroom walls. The shower in the bathroom is attached to one of the bathroom walls. When the shower is open, it is prone to get wet the shower attached wall. This causes it to penetrate the water inside the wall, and it tends to dampen the wall. As a result of this wall can be discolouration, mold, and mildew growth can occur over time. Therefore you should properly waterproof the bathroom wall.