Designing Against The Grain: The emergence of rice flooring

Sharp fluctuations in price and availability further urged the quest for an alternative product. Out of their facilities in the Far East, the manufacturer assigned a team to find a viable alternative—several reiterations (spanning close to a decade) were needed to come up with a product that appeared natural and could be handled like wood. The result was a very wood-like looking material that, despite being completely wood-free, could be cut, sanded, stained, and refinished, or left natural and untreated, to create various pieces. Rice husk was blended, extruded, and treated to produce a natural material in appearance. Unlike wood composite products, rice products are not prone to fading.

Additionally, while many WPCs come pre-stained, ‘new-generation’ rice-based products are sold unfinished and can be worked like real wood. If electing for a stain, it is important to test the stain first. Since the rice material is essentially non-porous, one must ensure the stain properly adheres to the material. Specific formulations for rice products are available in various colours.

Using rice husk in decking and cladding
Given its unique structural advantages, as well as the tremendous esthetic appeal of some products, rice decking and wall cladding applications are becoming increasingly more prevalent throughout North America in various climates. Decking applications typically require runners to be pre-installed so as to allow for proper drainage. As rice hulls are fairly moisture-free, expansion and contraction of wood-free products tends to be minimal (if at all), so planks can be installed very close to each other with very little spacing. (When the rice-based product also incorporates composite wood, expansion, contraction, and fading may be more pronounced.)

Wall cladding
In addition to deck installation, rice-based materials may be used for wall cladding. Installation is typically done over pre-installed rods but will differ greatly based on use and application. Typical details will also vary greatly depending on design. Generally, pieces come in left, right, and corner profiles.

Installation near pool areas
Certain rice-based decking materials have been found to be extremely skid-resistant and therefore ideal for installation near pools or wet areas.

Stairs
Using decking planks, panels, or a combination of both, stairs can be constructed to fit any customized area.

General information
The following instructions are obtained from a specific manufacturer of rice decking product and are intended for a general reference only. This installation applies to site- finish rice decking products. For installation instructions on any specific product, the designer must consult that manufacturer’s documentation.

1. Decking should be installed by an authorized professional.
2. One should ensure a slope of approximately two degrees for adequate water drainage. If ponding water freezes around decking or joists it can cause damage.
3. Allow for temperature-dependent linear expansion as indicated by the manufacturer.
4. Only use construction fastening material and hardware suitable for outdoor use (e.g. stainless steel screws).
5. When using screws, pre-drill the product on a flat surface. One only needs to drill the first plank installed, and screws can be hid effectively with a dowel.
6. Consider local building codes as well as the installation instructions and technical information.
7. To ensure the necessary stability, the joists should typically be applied at a maximum distance of 406 mm (16 in.), ensuring a maximum overhang of 25 mm (1 in.) at the ends.
8. The concrete base or suspended substructure onto which the runners are fixed must be stable. Where cement is used, ensure adequate drying time for the cement to stabilize and harden.

(This normally takes about five days for non-quick-drying cement.)

• When butting the planks, one joist should be used for each clip; therefore, double runners should be installed where the planks are butted.
• When installing planks next to each other, gently tap planks into place. Each one needs to be fixed with a clip on the joist.
• The end plank should be fixed with a screw and dowel.

Applying ‘glaze’

1. Before applying a glaze finish or sealer, remove stains or harsh dirt marks with sandpaper. Use sandpaper with grit between
   24 and 60 max.
2. After sanding, remove all dust.
3. For details on applying one’s preferred surface finish, follow the appropriate application instructions provided by the manufacturer.
4. Apply surface finish in the gaps with a small brush.
5. Important: As rice hull material is particularly impenetrable, it is highly recommended one tests any stain before undertaking a complete application. This is done to observe if and how the stain will adhere to the material.

Conclusion
Rice hulls have proven to be a technically and environmentally beneficial material with over a decade of successful application in various forms of construction. It is recent improvements in the esthetic appeal of rice-based materials, however, that will lead to the continued commercial success of rice hulls in various aspects of construction.

Tamar Royt, BA, LLB (JD), MBA, is the founder and president of Toronto-based Silverwood Flooring, a provider of flooring products to the design and construction industry. Since 2005, she has been working with leading developers, architects, and designers to introduce well-designed, environmentally responsible flooring to the Canadian market. Royt is ranked on the Profit W100: Canada’s Top Women Entrepreneurs and is a contributing member of several industry associations, including the National Wood Flooring Association (NWFA), Canada Green Building Council (CaGBC), Association of Registered Interior Designers of Ontario (ARIDO), Ontario Retirement Communities Association (ORCA), and the Building Industry and Land Development Association (BILD). She can be contacted via e-mail at tamar@silverwoodflooring.com.