Durock and Fiberock are United States Gypsum Corporation’s (USG) flagship products.
Both backer boards are typically used as a substrate for tile, but when should you choose one over the other?
The main difference between Durock and Fiberock is the composition. Durock is a type of cement board. Fiberock is an engineered gypsum underlayment more similar to drywall. The former is suitable for indoor and outdoor applications. The latter is designed for the interior only. Both are ideal for floors, walls, and countertops, but Durock is a better option for wet areas.
What Is Durock?
Durock is a type of cement board typically used as underlayment for tile in tub and shower areas. It is also used as a tile substrate on floors and countertops, and it can be installed both indoors and outdoors.
What makes it different from other cement boards is the EdgeGuard, a proprietary, reinforced edge that allows for seamless installation.
The reinforced fiberglass mesh also makes these panels easy to cut with minimal crumbling.
What Is Fiberock?
Fiberock is a type of fiber-reinforced gypsum board. What makes it different from drywall is the gypsum core sandwiched between two fiberglass-reinforced sheets of cement.
Despite being thin, these sheets are definitely thicker and more resistant than the paper sheets found in conventional drywall.
Because gypsum is less water-resistant than cement, Fiberock is not the best choice for tub and shower areas. However, it is an excellent choice for tile and a variety of other flooring and countertop materials in all other spaces.
Durock Vs. Fiberock: 11 Key Differences
Both Durock and Fiberock are backer boards used for tile. However, there are some crucial differences between the two.
The table below shows a comparison between these two underlayment types:
| Characteristics | Durock | Fiberock |
|---|---|---|
| Composition | Aggregated Portland cement slurry with polymer-coated fiberglass mesh | Fiber-reinforced gypsum with water-resistant core |
| Installation | Easy | Easy |
| Application | Interior and exterior | Interior only |
| Mortar type | Latex-fortified mortar or type 1 organic adhesive | Latex-based type 1 mastic or latex-modified thinset |
| Fasteners | 1.25" backer board screws | 1.25" to 1.625" screws |
| Water resistance | Water durable | Water-resistant |
| Rigidity | More rigid | More flexible |
| Thickness | 1/4", 1/2" or 5/8" | 1/4", 3/8", 1/2" or 5/8" |
| Eco-friendliness | 75% recycled materials | 97% recycled materials |
| Price | Cheap | Cheap |
| Best for | Tile base for tub and shower areas, underlayment for tile on floors and countertops | Underlayment for tile, stone, vinyl, hardwood flooring, laminate flooring, carpeting, and countertops |
1. Composition
As mentioned, the main difference between Durock and Fiberock is the composition.
Durock is made of Portland cement slurry reinforced with a fiberglass mesh. The aggregates – which aren’t disclosed by the manufacturer – and the fiberglass reinforcement enhance resistance and lower the crumbling problem.
This makes it possible to obtain straighter edges while cutting the panel, which translates into an easier installation.
Fiberock is best defined as a hybrid between drywall and cement board.
These panels feature a gypsum core sandwiched between two thin sheets of Durock-like cement. The exterior sheets are fiberglass-mesh reinforced, a feature that increases durability and resistance.
Fiberock is typically easier to cut and work with compared to Durock, but the latter is a better choice for wet applications.
2. Installation
Both Durock and Fiberock are easy to install, even though Fiberock is typically easier to work with.
The main reason is Fiberock’s lighter weight compared to Durock. Because it is made mostly of gypsum, Fiberock is also easier to cut.
However, Durock’s EdgeGuard technology allows for a quick and seamless installation of these boards, too.
3. Application
While Durock and Fiberock are often used as tile substrates, each panel type is best used for different purposes.
As a cement board, Durock is suitable for interior and exterior applications. The board can be an underlayment for floors, walls, and countertops, but it is commonly used as a drywall alternative in tub and shower areas.
Fiberock has a gypsum core, which doesn’t handle moisture as well as cement. However, the material is often used as an underlayment for partially tiled bathroom walls – paint has a higher adhesion on Fiberock than Durock.
Fiberock is also suitable for substrates other than tile, including hardwood and laminate floors, vinyl, carpets, and countertops.
4. Mortar Type
Durock and Fiberock are manufactured by the same company and both work with similar mortars and adhesives.
Because Durock can be used outdoors, too, the recommended mortars are slightly different.
For outdoor applications, Durock works best with latex-fortified mortar. Indoors, it is recommended to use type 1 organic adhesive.
Fiberock is designed for indoor use only, but you can pair it with latex-based type 1 mastic or latex-modified thinset, depending on the finishing product.
5. Fasteners
A similarity between the two backer board types is the fasteners you can use them with.
Durock requires 1.25″ backer board screws. Fiberock requires the same fastener type, even though it can also be used with 1.625″ screws.
6. Water Resistance
As far as water resistance is concerned, neither of the two boards is waterproof.
However, Durock has a higher water resistance than Fiberock. This is mainly due to its composition consisting mostly of cement – even if cement is porous, the material isn’t affected by water.
Gypsum is somewhat soluble in water, becoming brittle and crumbly with constant exposure.
For this reason, Durock is a better option than Fiberock in tub and shower areas. Fiberock can still be used in bathrooms and is a good choice for partially tiled walls.
7. Rigidity
Considering that Durock is made of cement while Fiberock is mostly gypsum, the former is stiffer. However, both panel types can be used for floors, walls, and countertops.
8. Thickness
A difference between these two backer boards is that Fiberock is available in 3/8″-thick panels, whereas Durock is not. Both types come in 1/4″, 1/2″, or 5/8″ thicknesses.
9. Eco-Friendliness
Making an effort to manufacture green construction materials, USG’s Durock and Fiberock are both eco-friendly.
Durock is made of about 75 percent recycled materials. With Fiberock, the brand takes things one step further – these panels are made of up to 97 percent recycled materials.
10. Price
Durock and Fiberock are manufactured by the same company, and they have similar prices. A 3×5-foot panel with a thickness of 1/2″ (of either board) costs around $10.68.
This price places Durock and Fiberock among the most affordable underlayment options, with similar products from competitor brands costing up to twice as much.
11. Best For
Both Durock and Fiberock are suitable to use for walls, floors, and countertops.
Due to easier handling and installation, contractors typically use Fiberock unless it’s a wet application in a tub or shower area.
Durock is also the only backer board between the two that can be used outdoors.
Final Thoughts
Durock and Fiberock are two backer board types manufactured by the same brand. Durock is a cement board, whereas Fiberock is a reinforced gypsum panel.
The best option for wet areas, such as tubs and showers, or for outdoor installation is Durock. However, Fiberock is easier to handle and often preferred in all interior areas except for the bathrooms.
