Durock and WonderBoard are two of the most common types of cement-based backer boards used for residential and commercial tile applications in wet areas.
Both are suitable to use on floors, walls, and countertops, but how do they compare?
Durock and WonderBoard are made of a Portland cement base mixed with aggregates. They are both reinforced with fiberglass mesh, but WonderBoard also contains EPS beads and is lighter. Both boards are suitable to use indoors and outdoors for wet and dry applications alike. WonderBoard is typically considered more flexible than Durock and is a better choice for curved surfaces.
What Is Durock?
Durock is a type of cement board manufactured by the United States Gypsum Corporation (USG).
This backer board type is known for its proprietary EdgeGuard that adds more resistance to panel edges and prevents crumbling.
What Is WonderBoard?
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WonderBoard is a type of cement board manufactured by Custom Building Products.
Allegedly, this backer board is around 20 percent lighter than other brands. However, the weight difference is minimal when compared to Durock.
Despite the fiberglass mesh reinforcement, this material is more brittle than Durock.
Durock Vs. WonderBoard: 9 Key Differences
Both Durock and WonderBoard are cement backer boards used for the same types of applications. Choosing one over the other is often a matter of preference, but the factors below can help you decide which is right for you.
The table below shows a comparison between these two cement board types:
| Characteristics | Durock | WonderBoard |
|---|---|---|
| Composition | Aggregated Portland cement slurry with polymer-coated fiberglass mesh | Portland cement, EPS beads, aggregates, reinforcement. No wood fiber or gypsum |
| Installation | Easy | Easy |
| Application | Interior and exterior | Interior and exterior |
| Mortar type | Latex-fortified mortar or type 1 organic adhesive | Polymer-modified thinset mortar |
| Fasteners | 1.25" backer board screws | 1.25" backer board screws |
| Water resistance | Water durable | Water resistant |
| Rigidity | More rigid | More flexible |
| Thickness | 1/4" or 1/2" | 1/4" or 7/16" |
| Price | Cheaper | More expensive |
1. Composition
Durock and WonderBoard are both cement boards, and they are both made of a Portland cement mixture.
Custom Building Products is more transparent about the materials they use, disclosing that WonderBoard Lite is made of Portland cement, EPS beads, and fiberglass reinforcement. The boards also contain aggregates, even though it’s uncertain which aggregates are used.
However, the company discloses that this product doesn’t contain wood fibers or gypsum.
The EPS–expanded polystyrene – beads are a lightweight thermoplastic that reduces the cement and aggregate content. Hence, it reduces the panel weight.
USG is more secretive as far as its cement board formula is concerned. We know Durock is made of Portland cement slurry, aggregates, and polymer-coated fiberglass mesh. However, it is uncertain which aggregates are used.
2. Installation
Both cement board types are easy to install following the same steps.
Durock and WonderBoard alike have textured and smooth surfaces. Either surface can face out, depending on what you use the substrate for.
For tile installation with mastic, mortar, or thinset, the rough side should face out. Adhesive adheres better to the smooth side.
3. Application
Another similarity between the two cement boards is the application – they are both suitable to use indoors and outdoors, in wet and dry environments.
Both board types are an appropriate choice for floors, walls, and countertops.
However, differences in characteristics (explained below) make Durock better for showers and exterior applications and WonderBoard better for countertops and curved surfaces.
4. Mortar Type
Despite being two cement boards, Durock and WonderBoard differ when it comes to the recommended mortar or thinset.
Durock pairs best with latex-fortified mortar or type 1 organic adhesive.
Latex-fortified mortar has improved adhesion, flexibility, and impact strength than conventional mortar.
It also boasts freeze thaw resistance, being perfect for outdoor application in all climates. It works great indoors, too.
Type 1 organic adhesive is an excellent choice for interior tilework. The product works for walls and floors alike, and it can be used with a variety of tile materials such as ceramic, porcelain, natural stone, quarry, and mosaic.
WonderBoard requires polymer-modified thinset mortar, which is a tile adhesive formulated for indoor and outdoor use. It can be paired with a variety of tile materials, but it is not as performing as latex-fortified mortar or type 1 organic adhesive.
5. Fasteners
While Durock and WonderBoard require the use of different adhesive types, the fasteners you can use with either board are the same – both types work best with 1.25″ backer board screws.
6. Water Resistance
Cement board is typically used as a drywall substitute for wet applications, and this might lead you to believe that cement board is waterproof.
However, neither Durock nor WonderBoard are waterproof – just like other cement boards aren’t waterproof either.
Both types are water- and mold-resistant, though.
Due to the presence of EPS bead filler, WonderBoard is more porous than Durock. This makes it a good choice for high moisture areas but not necessarily wet applications, such as shower stall walls or floors.
Durock works best for wet applications.
Both Durock and WonderBoard can be treated to become fully waterproof, and neither panel is damaged by water.
7. Rigidity
Another essential thing to consider before choosing one brand over the other is the stiffness of the material.
Durock is typically stiffer than WonderBoard, providing more resistance to floors installed on studs rather than a solid subfloor – you should still install it over a plywood sheet, though.
WonderBoard is more flexible and a better choice for curved surfaces, such as curved walls.
8. Thickness
Durock and WonderBoard are both found in 1/4″ thickness, which is ideal for all applications. However, if you want a thicker product for the floor, Durock is also available in a thickness of 1/2″.
WonderBoard also comes in a thicker version, but it’s only 7/16″. This gives Durock another advantage if you’re looking for the right flooring substrate.
9. Price
There aren’t huge price differences between Durock EdgeGuard and WonderBoard Lite, but the former is more affordable.
Specifically, a 1/4″ thick, 3×5-foot Durock panel costs around $12. A WonderBoard Lite sheet of the same size and thickness costs around $18.
Summary
Durock and WonderBoard are two solid drywall replacement options for wet or outdoor applications.
Durock is stiffer and more water resistant than WonderBoard, working well for exterior or wet area applications. WonderBoard is more flexible and lighter, and it is an ideal choice for curved walls or counters.
Both backer boards can become fully waterproof after treatment, and both of them are easy to handle, install, and use as substrates for most tile types.