Is backer board the same as cement board?

Asked By: Kesha Itegui | Last Updated: 3rd February, 2020
Category: home and garden indoor environmental quality
4.1/5 (1,135 Views . 15 Votes)
Also called a cementitious backer unit or CBU, backer board is made of cement, water, silica, limestone flour, and fibers such as Kevlar or fiberglass for strength. Because cement backer board is porous, thinset, grout, and mortar adhere well to it.

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Also, is Hardie board the same as cement board?

One particular contractor in Colorado Springs relishes the opportunity to expound upon the finer points of Hardie Board, but according to most contractors they are relatively the same thing. Hardie Board is the best known brand of cement board siding, which is often called fiber cement.

Furthermore, do you need to mortar backer board? You cannot put a cement backer board over that. You need to put a layer or plywood, minimum 5/8 IIRC, over those boards, then mortar the backer to the plywood. Those 1x8 boards won't give a solid foundation and will flex. Over time, that will cause tile to pop loose or crack.

Keeping this in consideration, what is a backer board?

Backerboard is a thin layer of concrete with fiberglass mesh on both sides. It is available in a range of sizes, but 3 x 5-foot sheets are most common. This project guide shows how to properly lay out your backerboard with a chalk line and using mortar to secure and level your floor before installing tile.

Can you paint cement backer board?

If painting, apply a drywall primer suitable for high-moisture areas, as recommended by the paint manufacturer and paint HardieBacker board as you would drywall. If wallpapering, prime surface of HardieBacker board with a primer suitable for high-moisture areas as recommended by the wallpaper manufacturer.

39 Related Question Answers Found

Can Hardie get wet before installing?

original packaging. James Hardie siding and trim products must be kept dry at all times prior to installation. If products become saturated before they are installed, the following problems may occur: OPEN JOINTS DUE TO SHRINKAGE If installed wet, joints between planks may open up requiring repair or replacement.

Which side of Hardie board goes out?

Cement board has a smooth side and a rough side. Face the rough side out if you will be using thin-set mortar adhesive to install the tile but the smooth side out if you will be using latex mastic.

Which is better Hardie board or durock?

Durock can be used for both internal and external situations. Durock is a reliable cement product that contains glass mesh. HardieBacker is much more light, and it is also the best selling brand of cement board available. It is much cleaner because it does not have any glass in it.

Is Hardie backer waterproof?


cement backer board is not waterproof,but water cant hurt it,even when soaked in water for months or even years

Does Hardie board absorb water?

Hardie siding does a great job of wicking moisture when it is installed on the wall, but when it's uncovered and flat on the ground it will absorb water. Luckily, it takes lots of water to saturate Hardie products! It's no problem for a contractor to install James Hardie products in light rain.

Does Hardie board mold?

Hardie Plank is a cement board; it's composition is sand and water. It is heavy on the wall and provides no insulation value. Formed to resemble wood, it fails to provide a deep, rich grain and does not come close to the look of wood. It is highly susceptible to mold and mildew.

What do you use cement board for?

Cement backer board is mainly used as a sub-surface for tiling. Cement backer board is often used as a tile base on plywood or OSB subfloor. Cement backer board on concrete as a subfloor or underlayment is usually not recommended or needed. In most cases, you can apply tile directly to the concrete.

Do you need to seal Hardibacker before tiling?

To Seal or Not To Seal
Contrary to popular thought, tile and grout are not waterproof, and some moisture will penetrate even if sealant is used. If you decide to go this route, no sealant will need to be applied on top of the backerboard, as this could trap moisture between the two layers of waterproofing.

What thickness backer board should I use?


Cement backer board comes in two standard thicknesses, 1/2 inch and 1/4 inch. The industry standard is to use 1/2-inch-thick backer board on wall tile installations, such as a tub surround.

What kind of screws do you use for Hardibacker?

Cement Board Screws are designed for attaching HardieBacker or equivalent fiber cement backerboard to wood or light gauge steel studs. Backer-On's patented serrated head design countersinks for flush seating at any angle, providing a smooth surface for tile.

When should you use backer board?

Use backer board for all your tile jobs, including floors, walls and counters. You can also use it for thin exterior brick and stone. Some companies manufacture backer-board sheets with a rougher side for use with thinset mortar and a smoother side for use with ceramic-tile mastic.

How many screws do I need for cement board?

Fasten a minimum of 12 screws into the board (4 rows of 3 screws). Keep fixings between 15mm from board edges and 50mm from board corners.

How thick should cement board be for tile?

Cement-fiber, or similarly reinforced, backer board comes in standard 1/4 inch and 1/2 inch thicknesses. If you're installing backer board over an existing subfloor, 1/4 inch is sufficient. If you're installing backer board in new construction, attaching it directly to floor joists, opt for 1/2 inch sheets.

What kind of Thinset do you use for Hardibacker?


To save a few bucks, you can use dry-set mortar under Hardi, but if you want to simplify things and deal with only one thinset, use a modified thinset like 253 Gold for both applications. Rialto is a porcelain tile that has deep depressions on the back.

What is the purpose of backer board?

The primary purpose of cement boards is to serve as backing for tile and is superior to paper-covered gypsum at this task because of its resistance to water – as tile is typically used in areas prone to water exposure, it is important to have a backing that will not develop mold and mildew or disintegrate after

Do I have to use thinset under Hardibacker?

Since you are putting down hardie board on boards with small gaps, I would not recommend trying to put down thinset under it. It will make an enormous mess under the house (or whatever is under your bathroom). It is also more likely to make the floor uneven since it is hard to level thinset that is separated by gaps.