When installing tile, you need a substrate with an almost impossible mixture of qualities. This substrate has to be solid. It cannot absorb water. Nor can it be made of organic materials since organic materials rot quickly in high-moisture environments. This substrate should be cementitious, or mineral-like. Finally, to add to the difficulty, this substrate must be cost-effective, easy to cut, and light enough to transport.
While a product with all of these factors might seem like a miracle, the miracle product is very much a reality: cement backer board. One popular brand of cement board is called WonderBoard—or properly, WonderBoard Lite.
What Is WonderBoard Lite?
WonderBoard Lite is a cement-based backer board mainly used for tiling in wet places. WonderBoard Lite is made by Custom Building Products.
WonderBoard Lite is made of Portland cement, expanded polystyrene (EPS) beads, aggregates, and fiberglass reinforcement. WonderBoard contains no gypsum—a major component of drywall.
WonderBoard Lite is 20-percent lighter than its previous iteration, simply called WonderBoard. Other cement backer board competitors on the market include Durock and HardieBacker.
Where to Use WonderBoard Lite
Like other cement backer boards, WonderBoard Lite is chiefly used for wet applications and for tiling.
The wet places are mostly bathrooms—specifically, showers and tub surrounds—and the applications tend to be tiling, but it can also be used under laminate countertop material. WonderBoard Lite is also used for decks, floors, countertops, pools, and hot tubs.
When you lay down tile, you need a backing base that will accept the thinset mortar. For flooring in kitchens, that backing is usually just plywood or another type of organic-based (wood) material, because this flooring is not subject to much water. The layers of tile and mortar, seamed with grout, do a serviceable job of shedding the minimal amounts of water that splashes in kitchens and even in the general floor areas of bathrooms.
Showers and bathtubs are a different matter. Water continually pounds these surfaces and eventually will work its way below. With only a pinprick-sized hole in the grout, that water will travel to the tile base. Once this happens, the road to rot is usually direct and swift.
If the tiler uses greenboard—a precursor type of drywall that is a bit more water-resistant than regular drywall—those shower walls may eventually fail. Cement board is the only acceptable base for shower and tub surrounds.
WonderBoard Lite Sizes
WonderBoard Lite dimensions are 5 feet by 3 feet. Thickness options are 7/16-inch and 1/4-inch. These sizes are consistent with other brands of cement backer board.
WonderBoard Lite and other cement boards usually do not come in large, 4-foot by 8-foot formats to reduce weight. Another reason is the breakage factor. Larger sheets of cement board are more prone to breaking than smaller sheets.
WonderBoard Lite Review: Pros and Cons
WonderBoard Lite has many advantages, including lower pricing in many retail outlets. WonderBoard Lite does have some limitations, too, such as edge integrity.
You may find WonderBoard Lite a challenge to work with due to its crumbly consistency. The only element that holds it together is the nylon meshing.
You can cut the backer board in either of two ways: manually or with a power tool. Manually, WonderBoard is cut with a utility knife or similar sharp cutting device. With a power tool, WonderBoard is cut with a saw or a grinder equipped with a diamond blade.
Cutting WonderBoard Lite with a utility knife is requires multiple passes of the knife. Crumbs of cement material may fall off, while the meshing resists the knife. Using a power saw or grinder is faster, but messier.
By contrast, HardieBacker, a competing cement backer board made by James Hardie Industries, is smooth and easy to cut manually. Durock, made by USG, is a similar competing backer board that has a smooth consistency.
Custom Building Products chiefly sells WonderBoard Lite, identified by the green band across it. This product weighs 22.6 pounds per sheet. But you may also find some of the other versions of WonderBoard still being sold. This red-banded WonderBoard is 44 pounds per sheet.
If you're looking to save costs, you might want to buy WonderBoard Lite. It is consistently less expensive than HardieBacker—about $3 less per sheet—but still hovering around the same price as Durock. At times, Durock's price will dip about $1 less per sheet than WonderBoard.
Due to the nature of the cement board, you will not be using this product over great expanses, like whole-house flooring. Instead, you will use cement board to install a few square feet for your shower. In this case, the cost may not be much of a factor when deciding between WonderBoard, Durock, and HardieBacker.