What is engineered wood siding?
Thursday, July 19, 2018
It is the newest generation of what used to be called composite wood siding. Engineered wood is made from chips of wood that are compressed with a water-resistant glue into both planks and panels for exterior siding. It is a similar material to OSB (Oriented Strand Board) used for sheathing, but with a hardened outer surface that can be ordered in textures to mimic real wood and pre-primed for painting.
Multiple manufacturers of composite wood siding—which was sold from the 1980s to mid-1990s—were the target of class-action lawsuits over the premature failure of the material. Moisture that got behind the paint finish or entered at a poorly nailed areas caused the material to balloon up and then crumble away in pieces. Settlements were issued to the claimants in many cases, and the period for accepting new claims has expired years ago. See our blog post What is the difference between "composite" and regular wood siding? to learn more.
In the same way that “mobile homes” were rechristened as “manufactured homes,” as a way to escape their previous shoddy reputation once the product had been improved, engineered wood really has vastly improved its moisture-resistance and renaming it was probably appropriate. LP Smartside® is the most popular of the new generation of engineered wood siding, and one of the improvements they made was coating the wood chips with zinc borate, a fungicidal chemical, before it is pressed into siding with resins and marine waxes. Smartside® has been on the market for nearly 20 years now and so far had none of the previous product’s problems.
Estimates of the lifespan of the material range up to 100+ years and the manufacturer provides a limited warranty of 50 years, so it’s likely that the actual life expectancy is somewhere between those two numbers. But it is still a fairly new material, and only time will tell.
We recently used 4’x8’ sheets of pre-primed Smartside® for a small remodeling project, and were pleasantly surprised. It is lighter than plywood, which makes it easier to handle, the pre-priming saves work at the jobsite, and it costs a little less too. Also, engineered wood does not need special tools for cutting, like fiber-cement products. It’s likely there will be a lot more engineered wood siding used on new homes in the coming years.
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To learn more about exterior walls and structures, see these other blog posts:
How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manfuactured and modular homes
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of Blog Posts