Engineered-wood products are an integral yet hidden component of home construction, but like a lot of building materials, they’ve had their challenges. Newer products on the market aim to make the construction site a dryer, happier, and more attractive place.
One of construction professionals’ biggest complaints is that board swells when wet. In fact, in a recent survey sponsored by Huber Engineered Woods, nearly half of the respondents said they preferred getting a root canal to dealing with plywood flooring that has swelled after a rainfall.
The edges of board present a particular obstacle because when they get wet they swell, creating fitting problems during construction. Workers have gotten around this by sanding off layers around the edges, but this adds labor and expense.
Ainsworth Lumber’s PointSIX Flooring, an OSB product released about a year ago, takes the work out of that preventative measure because a thin layer of the board is milled and treated around all four edges to prevent swelling. PointSIX products are available in Ainsworth’s standard OSB and Durastrand flooring.
The product was launched after extensive research and testing, including subjecting the panels to repeated wet and dry cycles to simulate severe wet jobsite conditions. In one test, PointSIX OSB was flooded for 14 days. After drying out, the average edge swell was contained to 0.01 inch, not much more than a sheet of paper.
“When installing OSB subfloor, some builders will coat the OSB with a water seal (which adds material and labor costs), while others will rush to weather-in the structure, hoping to get the subfloor covered before any rain,” says Bart Bender, Ainsworth’s vice president of sales. “PointSIX OSB flooring helps avoid having to do either of these things, as it eliminates the edge swell of OSB. Because we mill off just 0.6 millimeters along a thin band around the edge of the OSB, any potential swell, if it swells at all, only brings the edge up to flush. The design is actually quite revolutionary.”
In February, Weyerhaeuser introduced its Hardwood Edge OSB floor panel. Specifically engineered for use under hardwood floors, the panels claim enhanced dimensional stability and high density for improved fastener holding. The design aims to solve the squeaky-floor problem caused by the inherent swelling and shrinking of wood, improper acclimatization of hardwood, and insufficient drying time if the OSB in the floor gets wet—all which work together to loosen fasteners.
“Hardwood Edge OSB panels are the first in the industry specifically designed to address the unique needs of hardwood floors, which are particularly susceptible to the effects of moisture,” says David Walters, tactical project manager for Weyerhaeuser OSB. “The self-gapping tongue and groove fits together easily, and our proprietary edge seal and patented drainage technology get water off the panel fast, minimizing the effects of rain.”
Along with improved fastener-retention and high density, the panels, which are available only in the Mid-Atlantic region, include the company’s “Down Pore” drainage technology: three grooves at panel ends that eliminate standing water to reduce the potential for moisture absorption. That built-in drainage, along with the panels’ proprietary edge seal, claims to reduce edge swell and virtually eliminate the need to sand.
Huber’s ZIP System takes the moisture protection and ease of installation a step further – actually, longer – with its long length sheathing, which boasts heights of 9 and 10 feet. Eliminating the need for housewrap, the product combines OSB with continuous built-in weather resistant barrier. Huber says the boards provide faster installation and easier compliance with energy codes, as well as increased energy efficiency for the homeowner.
“The introduction of the ZIP System long-length sheathing fills a void for builders looking for long-length panels incorporated with the innovative technology of ZIP System sheathing and tape,” says Charlie Robinson, ZIP System products general manager. “The panels’ long length is ideal for faster installation, and the ZIP System technology tailors that efficiency with superior moisture, air, durability, and overall quality.”
Walls and floors aren’t the only places where engineered wood is in use and needs extra protection from Mother Nature.
In July, LP Building Products launched its LP SolidGuard LSL, which controls moisture and adds protection against termite damage and fungal decay to its LSL product. Moisture content in dried lumber may be up to 19%.
Over time, the lumber will dry down to the moisture equilibrium of the finished building—typically 8% to 12%—causing the wood to shrink and potentially resulting in misaligned framing, broken window seals, and damaged plumbing. The new products contain a 7% to 10% moisture content, similar to the moisture equilibrium inside the building.
“Shrinkage is a concern for lumber in multi-story structures as it can affect shear-wall performance and structural capability,” says Kim Rogers, EWP product manager for LP Building Products. “Using LSL for wall plates and sill plates can significantly reduce plate shrinkage. Our new product provides our customers with a full wall plate solution for taller wood-framed buildings.”
Anthony Forest Products had cost savings in mind in the fall of 2012 when it introduced the Power Rated Glulam or PRG 2400F—1.9E glulam for beam and header applications. The 3.5-inch and 5.5-inch widths at IJC depths up to 18 inches balanced layup and zero-camber beam will match up with all other engineered wood products. The PRG sizes and comparable design values will allow easy substitution while eliminating duplicate inventories.
“Our goal is to help the stocking distributors and retail lumberyards to reduce the overall SKUs of other EWP while allowing substitution of the Anthony PRG glulam at a lower installed cost,” says Kerlin Drake, vice president of marketing for Anthony Forest Products.
With all of these new choices, engineered-wood products are holding their place all around the house as a prime construction material.
—Sarah Humphreys is a freelance writer based in Los Angeles.