What should you put down before tiling a bathroom floor?

Author: Keshaun Nolan  |  Last update: Thursday, December 11, 2025

Install a cement-based backer board following the manufacturer's instructions. This provides a solid surface under the tile that prevents flexing that could lead to cracking. Backer board panels typically measure 3-feet by 5-feet and can be trimmed as needed.

What do you put on a bathroom floor before tiling?

Tile is best laid over a cement based underlayment. Concrete board or ``Hardy Backer'' is a good choice. This underlayment should be screwed down and screw indents filled with leveler or embossing compound.

What should I lay on my floor before tiling?

You can't, however, lay tiles directly over wooden floorboards, as the flexibility of floorboards makes them susceptible to movement, which could cause tiles and grout to crack and break. There is no need to concrete over the boards or rip them up before tiling, however, you will need to use plywood or backer boards.

What is the best base for tile flooring?

Best practices for proper installation of ceramic tile is either using cement based backer board or applying a mortar bed.

Do you have to waterproof a bathroom floor before tiling?

Yes, waterproofing a bathroom floor is highly recommended. Bathrooms are exposed to high levels of moisture from showers, baths, and sinks, which can lead to water damage, mold growth, and structural issues over time. Here are some key points to consider:

Tile Floor 101 | Step by Step How to Install Tile for the First Time

What to do before tiling a bathroom?

How to Prep A Bathroom for Tiling
  1. Step One: Remove Old Bathroom.
  2. Step Two: Plumbing & Electrical.
  3. Step Three: Sheet the Floor.
  4. Step Four: Sheet and Set the Walls and Ceiling.
  5. Step Five: Frame the Windows & Doors.
  6. Step Six: Screed the Floor.
  7. Step Seven: Waterproof over Bedding.
  8. Step Eight: Shop for Tiles!

Do I need cement board under bathroom tile?

One of the first questions that many people before installation is whether to use plywood or cement board under tile. While you can technically install most tiles on any smooth, clean substrate, using cement backerboard will give you superior results every time.

What to put under tile in a bathroom?

Install a cement-based backer board following the manufacturer's instructions. This provides a solid surface under the tile that prevents flexing that could lead to cracking. Backer board panels typically measure 3-feet by 5-feet and can be trimmed as needed. To cut backer board, measure and mark the size you need.

Do you need a membrane under porcelain tiles?

Anti-cracking membranes, such as Kerakoll Biotex are ideal for ceramic tiles of all kinds, large formats, porcelain tiles, clinker, and natural stone to reduce tensile and shear movements between the substrate and the surface finish.

How to prepare a floor for tiling?

It needs to be even, flat, dry and free from damp, and the correct adhesive must be used. If you've had other tiles or sheet flooring, you'll need to remove any adhesive from the floor before beginning. If the floor surface is dusty, prime it with diluted PVA adhesive and leave it to dry.

What is the 3/4/5 rule for tiling?

To get a perfectly square corner, you want to aim for a measurement ratio of 3:4:5. In other words, you want a three-foot length on your straight line, a four-foot length on your perpendicular line, and a five-foot length across. If all three measurements are correct, you'll have a perfectly square corner.

Can I tile straight onto plywood?

Can you tile on plywood? Yes, but various considerations need to be made first. If the floor consists of sheets that do not support each other, it is necessary to ensure that each edge is fully supported underneath.

What should you not put on tile floors?

Cleaning Other Types of Tile Flooring

Avoid cleaning products that contain lemon, vinegar or other acidic substances. Do not use vinegar or chemicals on granite or marble tile floors.

What are the steps to tiling a bathroom floor?

Here's a detailed guide to help you achieve professional results, integrating key tips and materials to ensure your project goes smoothly.
  1. Step 1: Measure the Floor. ...
  2. Step 2: Cut Sub-flooring. ...
  3. Step 4: Test Your Layout. ...
  4. Step 5: Cut Tiles. ...
  5. Step 6: Lay Remaining Tiles. ...
  6. Step 8: Apply Grout. ...
  7. Step 9: Apply Sealant.

What do you put on plywood before tiling a bathroom?

You can install tile on plywood, but you must take a few precautions to prevent the plywood from cracking the tile. The best direct underlayment for tile on plywood is cement board or an uncoupling membrane. Follow these steps to install and use plywood as a substrate for ceramic, glass, stone, or porcelain tile.

What do you put behind bathroom tile?

A cement board is often the best choice due to its robust moisture resistance and ability to support the weight of the tiles. This foundational layer is key to preventing water seepage that could otherwise lead to mould growth and structural issues.

What is the best sub base for porcelain tiles?

Do porcelain slabs need a concrete base? To lay porcelain slabs outside, they should be ideally applied to a solid substrate base, such as concrete, or a sand and cement mix screed of 4 parts sharp sand (or grit) to 1 part cement.

Do you need a waterproof membrane for a bathroom floor?

Yes, it is essential to waterproof your bathroom floor before tiling to ensure that your bathroom is well-protected against water damage caused by leaks or seepages.

What happens if water gets under porcelain tile?

While tile floors are known for their durability and water-resistant properties, they are not impervious to the effects of moisture. Over time, excessive water exposure can weaken the grout, cause mold and mildew growth, and even result in the lifting or cracking of tiles.

What to do before tiling a bathroom floor?

Before any tiles are laid there are some essential steps that must be taken to ensure that your bathroom floor is properly prepared to ensure a professional result. This includes preparing the subfloor, cleaning the surface of the floor & walls, screeding and the application of a waterproof membrane.

How to waterproof a bathroom floor before tiling?

Seal with Silicone
  1. Using a caulk gun and silicone seal, fill the seams between the floor and the wall.
  2. Fill any cracks in the floor as well.
  3. Cracks and gaps will attract moisture, so sealing them completely is an important step in making sure your floors are entirely waterproofed.
  4. Allow to dry for 24-hours.

Is it better to tile over plywood or cement board?

Plywood may be the more budget-friendly option, but it is less moisture-resistant and stable than cement board. Cement board is better for areas with movement, water exposure, and subfloor imperfections, like kitchens, bathrooms, and laundry rooms. But plywood is an acceptable choice if your subfloor is dry and stable.

What is the best underlayment for tile?

Backer board is the most favored tile underlayment option when installing ceramic or porcelain tile. It comes in rigid panels that contain a blend of cement, fiberglass, and sometimes crushed glass particles.

What is a substitute for cement board?

Mat-faced gypsum cover boards are increasingly used as a cement board alternative because they are lighter and easier to install. There are also performance enhancing benefits that mat-faced gypsum cover boards have over traditional cement alternatives.

What is the best board for a bathroom floor?

Cement backer board is waterproof, making it an ideal choice when it comes to tiling areas that are directly exposed to water such as showers, bathrooms, and wet rooms.

Previous article
How long can clothes be soaked?
Next article
Does putting ice in fridge make it colder?