How to Waterproof Bathroom Floors

Your bathroom is going to see a lot of water damage, let’s face it. It’s where you run your bath, shower your pets or kids, run your faucets and flush your toilet, so it sees more water than almost anywhere in your house.

Waterproofing your bathroom is a beginner task that can take you only a few hours of work over the course of about three days. There are plenty of products to make the job easier and are affordable.

It isn’t just regular use that can happen to your bathroom, either. Faucets can burst, toilets and tubs can overflow. By waterproofing your bathroom, you could protect your floors from all these damages as well as from pet stains and other spills. Waterproofing now could save you a fortune on floor damage later.

How to Waterproof Bathroom Floor

Clean and Prepare Floor

Your first and most labor-intensive step is to thoroughly clean your floor. If you have wood floors, sand them down with a medium-grit sandpaper. Be sure to have plenty of ventilation in the bathroom during the whole process, open all windows and run a floor fan to dry products faster.

  • Vacuum, sweep, and mop your floor, allowing it to completely dry before moving on.

Prime Your Floor

Choose the correct floor primer for your type of flooring. If you are working with multiple types or aren’t sure, there are plenty of multi-surface floor primers available to you.

  • Use a paint roller tray and paint roller to apply the primer.
  • Start in a far corner and prime the edges of the room first.
  • To fully waterproof the room, apply the primer up the wall about six inches. If waterproofing a shower recess, apply six feet up the wall.
  • Apply a smooth, even layer of primer along the whole room.
  • Allow to dry for at least 4 hours, or as recommended by the primer you’re using.

Seal Edges

You’ll want to use a silicone seal to do this, as it is more durable and waterproof than caulking and other sealants.

  • Use a calk gun and a silicone seal you trust and fill in the seams between the wall and floor.
  • Fill in any cracks in the floor.
  • Allow to dry for 24 hours.
Red Devil Silicone Seal

Red Devil Silicone Seal

  • Provides a durable & watertight seal
  • Excellent adhesion
  • Easy application & tooling

Cracks and gaps in the lining or the floor allows moisture to gather, so seal any that you find and make sure you allow the silicone to completely dry.

Once the silicone and primer have dried, use a masking tape to line where your primer ends on your walls or along your edges. This will act as a guide for your sealer.

Apply the First Layer of Waterproof Sealer

Like the primer, use a paint roller and try to make an even and level coating.

  • Apply sealant to the walls and edges first.
  • Apply from the back of the room to the exit when using the sealant.

This is where ventilation is important, so keep those windows open and those fans going. This protects you from harmful fumes and speeds up the drying process.

(Optional) Apply a Waterproof Membrane

If you’re waterproofing a floor before adding any new flooring, consider a waterproof membrane. These come in strips that you lay out and cut down to the size you need. Membranes guard against any moisture that comes from above or below the surface and reducing risk of mold or mildew.

  • Lay your membrane over the gaps between the wall and floor, cut exactly to size.
  • Spread another layer of waterproof sealer over the membrane, be sure to keep the membrane smooth.
  • Allow to dry for another 24 hours.
Kaermo Waterproof Membrane

Kaermo Waterproof Membrane

  • Strong puncture release performance, can play a role in stopping root thorns
  • Good flexibility and easy to bend can be folded at will, made into a right angle construction, not easy to damage
  • Suitable for wet environment construction, play the role of blocking

Waterproof membrane is useful for if you’re worried about any gaps or crevices, or even just want that added layer of protection. If you are especially wary of water damage, this is an added bonus to your work.

How to Waterproof Bathroom Floor

Apply the Second Layer of Waterproof Sealer

Do the same as you did before, apply to the edges and the rest of the room as evenly as possible. Allow to completely dry for 24 hours as you did before, leaving fans running and windows open. 

Once everything is completely dry, remove your masking tape and enjoy your waterproofed bathroom!

Choose a Water-resistant Flooring

One way to protect your floors from water is to choose the proper flooring. Certain materials are more suited to resist water than others, so if you’re looking for a new flooring altogether to protect against water, you have a good stretch of options to choose from.

5 floorings that are water-resistant are:


Classic, widely available, and coming in a multitude of colors and shapes, ceramic is a timeless flooring that is both fashionable and versatile.

SomerTile Ceramic Floor and Wall Tile

SomerTile Ceramic Floor and Wall Tile

  • First-quality porcelain tile for floor and wall use
  • Glazed smooth finish with a low sheen and moderate variation in tone
  • Designed to have the look of Carrara marble, this porcelain tile has a classic look and a smooth, matte finish


Just as classic as ceramic, porcelain can be more expensive than ceramic but more water-resistant.

SomerTile FCDASBX Porcelain Floor and Wall Tile

SomerTile FCDASBX Porcelain Floor and Wall Tile

  • First-quality porcelain tile for floor and wall use
  • Glazed, smooth finish with a medium sheen and uniform appearance in tone
  • P. E. I. Rating III is suitable for medium-duty residential floors


More expensive than ceramic or porcelain, natural stone is versatile and rustic. It also happens to be porous, so be sure to give it some protection if you don’t want it to discolor. Slate tile is durable and warm, so it’s a great choice.


Vinyl isn’t often thought of as anything luxurious, but if it’s installed correctly and you get a more quality vinyl, you won’t have to worry about your floor underneath. If you think slipping will be an option, get a textured vinyl.

Waterproof Hardwood

Wood isn’t usually thought of for bathrooms, but this type of flooring consists of a water-resistant hardwood over a layer of proofed material that will give you the look of hardwood without any of the upkeep.

When installing these kinds of floors, make sure to use proper spacers and techniques. Water damage will attack the grout before it ever gets to the flooring, so protect your spaces and choose the right flooring for your bathroom and you’ll be all set!

Naacoo Flooring Spacers

Naacoo Flooring Spacers

  • Very Hard
  • Regular Shape
  • Perfect ABS Material, not PP plastic Degrees


Whether you want to waterproof your bathroom with readily-available waterproof sealants or simply choosing a flooring that will resist water damage, they’re all within easy reach and at affordable prices. This is a quick home improvement project that only takes a few hours within a few days, and can save you money on flooring and liven up your bathroom space.

KBRS Waterproof Sealants

KBRS Waterproof Sealants

  • KBRS ShowerSeal polyurethane sealant is used around the showers drain
  • KBRS ShowerSeal gauging fabric is a woven polymeric material that will strengthen the bond
  • 100% leak-proof shower experience