Which backer board to use when tiling

Also remove and fix any floor damages such as uneven, warped or loose floorboards. To avoid excessive flex which can lead to tile cracks, make sure:. The spacing between the joists should not exceed mm centres. The board joints should be staggered in a brick pattern and should not align with subfloor joints, all corners of the boards should never meet at one point.

Gaps of 3mm or more between the wall edges and the floor should be filled with adequate moisture resistant sealant. The boards can be easily scored and snapped using a HardieBacker scoring knife. Apply a gap filing bed of tile adhesive using a 6mm notched trowel , the 6mm HardieBacker board should be slowly embedded into the wet adhesive with a sliding motion, firmly and evenly. The boards are fixed to the subfloor surface using a minimum of 12 screws into the board 4 rows of 3.

Ensure to keep fixings between 15mm from board edges and 50mm from board corners. Alkaline-resistant tape should be placed over the joints and then feather the tile adhesive to leave a mm wide joint. When tiling with a cementitious-based tile adhesive, prime the face of the board with one coat of BAL Primer — diluted by volume of water. Watch the how to video here. Both 6mm and 12mm HardieBacker cement boards can be used on masonry walls. HardieBacker can take up to kg of tile hanging weight per m2 so almost any tile can be fixed.

The boards should be installed onto a clean and smooth surface and all dry lining removed prior to installation. Place three vertical, mm, beads of high strength cartridge adhesive evenly down the back of the board and press firmly against the wall. The board joints should always be staggered in a brick pattern and fastened with 9 6mm x 60mm stainless steel screws into brown wall plugs. Screws should remain mm from the top and bottom edges and 50mm from the left and right edges.

Ensure you do not overdrive the screws and the screw remains flush with the front of the board. Once secured cover the joints with Alkaline-resistant tape and feather the tile adhesive to leave a mm wide joint. These are the most commonly used tile substrates :. Made of cement and reinforced on the top and bottom with fiberglass, this waterproof backer board is generally used for tiled shower surrounds and floors in wet areas. It can also be used for exterior tiling jobs. Fiber cement board, also known as fiber board, is made from a sheet of Portland cement mixed with sand and cellulose fibers.

Fiber board is recommended for floor tile installations, since thin-set mortar adheres well to it, ensuring a strong tile-to-floor bond. Made from water-resistant gypsum treated with silicone, glass mat gypsum board is reinforced with fiberglass mats on top and bottom.

This type of backer board is lighter than cement board and is ideal for damp spaces like the tub surround in the bathroom, although it can become damaged if water gets behind it. While not considered backer board, water-resistant drywall can be used in spaces where occasional splashes may occur but which are otherwise dry, such as a glass-tile backsplash in the kitchen. Alternatively, instead of backer board, you can use two layers of plywood topped with a waterproof uncoupling membrane, which is a lightweight plastic underlayment that allows independent movement between the tile and the plywood to prevent cracks in the tiles and grout.

Backer board is usually a simpler way to go than plywood. Laying tile directly on a surface like plywood or an existing floor can cause major problems down the road. Tile installed directly over wood will likely buckle as it absorbs moisture, and the wood will be susceptible to mold and mildew.

Additionally, wood substrates expand and contract with temperature and humidity changes, which makes it an unsuitable surface for tile. Tile laid directly over an old linoleum or vinyl floor may shift and break if the surface contains air pockets or is susceptible to moisture.

Laying tile directly on an existing floor can also cause problems if the tile is very heavy or will be supporting heavy furniture. Half-inch cement backer board is ideal for most tiling jobs, including walls, floors, countertops, and ceilings. What materials are they made from? What problems do they claim to solve and which do they actually solve? They are all made with inorganic materials — lightly aggregated Portland cement with fiberglass reinforcement.

They are designed to be impact resistant, fire resistant as well as a rigid, efficient bonding substrate for tile. The modern versions of these boards often contain polymers with a finer fiberglass mesh on front and back, and wrapped around the long edges. These boards are NOT moisture resistant, and in fact most absorb moisture quite readily.

However, extra additives in these boards allow them to resist fungal growth and deterioration when exposed to water. There are a few versions of these boards from different manufacturers, but they all utilize cellulose fibers wood fibers to make the board more flexible less brittle.

Similar to cement backer board, these boards are generally uniform in composition not layered. Some boards incorporate a mixture of silica sand and cellulose fibers while others use gypsum and cellulose fibers. These boards can be very similar in price to cement board, or as much as 1. Glass Mat Gypsum board is a layered product composed of a gypsum inner core with a fiberglass layer on the front face and back face of the board. Although these products look much like regular gypsum wall board they have an entirely water resistant, paper free mostly fiberglass surface, and a water resistant gypsum inner core.

These boards can vary in price from some being similar to cement board, to as much as 1. Most foam backer boards are made from extruded polystyrene foam, but a few are composed of high density polyisocyanurate closed-cell foam as well.

In most cases, no additional waterproofing is required after installing these boards and sealing the seams and fasteners. Most manufacturers of these boards make them in several thicknesses so they can be used to create structural assemblies like benches and partition walls. Foam shower tile backer boards are generally about 4x the cost of cement board.

If they fracture from being distorted over an uneven wall, they can lose their structural integrity and water resistance. Keep in mind that this comparison will include the physical and functional differences in shower backer boards but also my opinions, based on my experience installing them and testing them. The confusing part is that the shower backer boards available on the market have a random assortment of these features, but none of the boards include all of these features.

The most obvious benefit of any shower tile backer board is to provide a secure bonding surface for your tile. The original tile backer board gypsum drywall board absorbed moisture, which tended to cause delamination between the paper face and the gypsum core.

This was the first of many problems with using drywall board as a shower tile backer. Cement board and all other tile backers tend to have a pre-bonded, textured surface that thinset mortar can stick to very securely.

Cementitious backer boards are still the only boards that guarantee high compression strength and unparalleled stiffness. This is important to limit movement and prevent your tile assembly from moving and cracking.

I would also like to stress that the rigidity of this type of board is quite minimal and may not withstand an impact from a large man falling against the shower wall without fracturing the grout. Foam shower wall boards are even more vulnerable in this sense. They have generally very poor compression strength and rigidity. In other words, if the finished tiled shower wall is left relatively untouched, it should all be perfectly fine.

Personally, I find these boards a bit too risky to install unless they are cement faced foam boards. The biggest brand of this type of backer board is Wedi. I have installed their products many times with great results. A simple fact is….. No significant moisture would reach the backer board, and the little that does would never condense into water. Excessive moisture would eventually cause any backer board to deteriorate even without the presence of mold.

The benefit of foam shower backer boards is that moisture would not easily make it through the board so this would offer some protection against mold growth within the board and the stud cavity. Most of the new generation tile backer boards are somewhat moisture resistant because of a dense surface coating like Densheild , or a very dense, uniform consistency like Hardibacker.

But none of the glass matt or cementitious boards can inhibit enough moisture to be considered a true waterproofing membrane.

The foam backer boards on the other hand, can inhibit a significant amount of moisture from moving through the board; enough to be considered a true waterproofing membrane. These boards are completely different than the other shower backer boards because of their closed cell foam core.

Because the foam backer board and foam shower pan products eliminate the need for an additional waterproofing membrane in most cases , they have become quite popular with DIY installers and professionals alike. Before you attach your tile backer board to the shower wall studs, the most important step you can take is to make sure that the wall studs are flat and plumb.

If you skip this step most installers do , and the stud plane is not uniform most are not , you will be creating tile lippage and tile registration problems , but you may also be compromising the water resistance and structure of your backer board.

If your shower wall studs are flat and plumb, there are a few hints below to help you correctly attach your shower backer board. I would definitely recommend that you use only official tile backer board screws when installing any cementitious backer board, including fiber cement board. One of the biggest problems with these products is that they can be quite brittle and can fracture easily if the wrong screws are used.

Ordinary screws even some coated screws can also corrode if they are not designed for moisture exposure. I always use Rock-On screws. These coated screws are corrosion resistant and can withstand the high alkalinity of a cement based shower backer board. The solution? I use a tile backer board countersinking bit designed specifically for this purpose that I use routinely when installing cement backer boards and fiber cement boards.

It also prevents fracturing the board or driving the screw in too far. Because the core of this board is gypsum, the screw installation method used for drywall board is pretty much the same, but you should always use tile backer board screws instead of drywall screws. Also similar to drywall board installation, you need to be very careful not to drive the screws in too far because if your screw breaks through the board face, it eliminates the holding power of the screw.

This bit is designed to create a depression in the face of these boards just deep enough to flush the screw head with the board face. Installation of foam shower backer boards is quite a bit different again, compared with the other backer boards.

Because these boards have such a flimsy low density structure, you usually need to use only the fasteners recommended by the manufacturer to attach these boards. They usually include large washers to increase the surface area of the screw head. Another big difference is that these boards function as both a shower backer board and a waterproofing membrane so all the fasteners must be covered with a sealer to maintain waterproofing integrity.

Or if you need some help on other bathroom remodel or shower remodel topics, please check out my shower remodel post. This post is for information purposes only and should NOT be interpreted as professional advice. You should always consult a licensed local contractor before undertaking any remodelling work in your home.

Privacy Policy. In my opinion, foam boards are generally adequate for inside walls, but I always prefer to install a standard cementitious backer board and a good sheet membrane like Wedi Subliner Dry for any outside walls.