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.
The choice would always be a cement board over ply, ply is not a stable material, it can expand, contract or delaminate and is effected by moisture. A cement board is an inert material, it doesn't suffer the same problems as ply, but must be installed correctly.
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.
DO NOT use any type of sheet rock board as a backer board for tile. Use Cement Board, Fiber Board, Hardie Board, Kerdie Board, or USG Tile Backer Board. These are all the correct products for tile because they are designed for thin set to be used on them and to be resistant against water.
Cement board is the preferred material of choice in high moisture areas. It very heavy but very durable. You might want to consider using cement board for shower area and bath regardless of the surface material. You can get away with green board for the remainder of the bathroom without any difficulty.
Can I Tile Directly Onto Cement Board? Yes, cement board is the perfect base for tiling, as it's waterproof and provides a smooth, even surface that won't be disturbed by moisture.
Betta Under Tile Membrane is a liquid rubber developed for wet area waterproofing under tiles, renders and surface finishes. Unique fast curing formulation, allows tiling and finishes to be applied over it after 4 hours once the application is complete.
If you lay tile on top of plywood, it'll expand over time, causing the tiles and grout lines to possibly crack and damage. The tile can't properly stick to wood as it can with concrete. Instead, lay a cement board on top of the plywood first or use a decoupling membrane.
Floors: A 1/4-inch minimum thickness is needed, but thicker panels are also acceptable. Walls: Use 1/2-inch or 5/8-inch-thick cement board, not 1/4-inch. Extra thickness is needed when spanning the studs, which provides a solid base for the tile.
Cement board is typically stronger in terms of moisture resistance and durability, making it ideal for areas exposed to water, such as bathrooms and kitchens. Plywood, on the other hand, is lighter and easier to work with, but it can be prone to warping and moisture damage if not properly sealed.
The best direct underlayment for tile on plywood is cement board or an uncoupling membrane.
Ditra is made by Schluter and is an “alternative” for the commonly used cement board or HardieBacker. You would use one or the other but not both. Many people use it primarily when laying tile on concrete, but I think its a solid choice with plywood subfloors as well.
Fiber cement board is a thin layer of concrete that is installed as a sturdy surface subfloor for tile setting. Backer board is made up of a sheet of cement mixed with sand that has a fiberglass mesh placed on each side of the board for durability.
Now largely regarded as the very best underlayment for ceramic tile in any application—floors, walls, and countertops—cement-based backer board goes by many names.
Use the substrate that was designed just for this use – cement backerboard. While plywood has many uses, and was once the only material to install tile on, it can't compare to the smooth, even surface of cement backerboard, or the stability that cement can bring to the job.
The thickness of the plywood needs to be at least 18mm and of exterior grade. It may be necessary to increase the thickness if heavy loads are anticipated or if the joists are spaced more widely than normal. Replace any defective sheets and fit noggins between the joists beneath any unsupported sheet edges.
Drill cement board screws through the backer board sheets every 6 to 8 inches. Position the screws at least 1/2-inch, but no more than 2 inches, from the edge of the sheet. Drive the screws in so that the heads are slightly below the surface of the backer board sheet.
The smooth side is ideal for mastic applications, as it increases adhesive coverage. The textured side is ideal for mortar applications, as it enhances bonding and reduces tile slip. That said, mastic or thin-set mortar can be used on either side of the board without compromising performance.
Hardiebacker is significantly lighter than Durock and WonderBoard, leaving this the lightest out of the bunch. How light it instantly makes it one of the most popular brands on the market. Since there isn't any glass mesh in it, unlike Durock, it makes the job much smoother and even minimizes the cleanup.
Plywood and tiles expand and contract at different rates due to temperature and moisture fluctuations (especially in bathrooms and kitchens). Therefore, you should never apply tiles directly onto a plywood subfloor. If you do, your tiles will likely slip or crack in time.
Traditionally, you would use modified thinset to adhere tile to a plywood subfloor. Due to its absorbent and porous nature, plywood is capable of sucking the moisture out of unmodified thinset. Leaving less water in the mixture will allow for less hydration, and cause a weak bond between the tile and the subfloor.
The following products are not suitable for direct bonding of ceramic tile or stone: luan, waferboard, masonite, particle board, oriented strand board (OSB) or sheathing, pressure-treated plywood, fire-treated plywood, interior grade plywood, hardwood flooring.
After installing your cement board or other backer board in your shower area, you can begin your tile-laying process. Be sure to add an extra waterproof layer if needed, especially for materials like a cement board.
This expansion gap should be filled with a silicone sealant to prevent it from being filled with tile adhesive when fixing your tiles. Before fixing your plywood overlay, ensure the reverse and edges of the boards have been sealed using BAL Bond SBR neat, as this reduces water permeability.
The most common thickness of tile backer board is 1/2-inch. Quarter-inch and 5/8-inch thicknesses can also be found. Use 1/4-inch backer board on curved applications or on vertical surfaces such as fireplaces. Use 5/8-inch backer board as a fire-rated material similar to Type X drywall.