Home & Garden

Well, once again, that miraculous, once-size-fits-all, end-of-all-your-troubles, maintenance-free thing turns out to be none of the above. This time it’s Trex decking, but there are lots of product defects out there so I’m certainly not going to single out Trex for lambasting.  

Part of the problem is that we keep looking away from what works in search of something new. That’s neither surprising nor all that disreputable an endeavor, but it usually leads us down a bumpy road. 

The building scientist, Joe Lstiburek (the L, unlike Joe, is silent), travels the country teaching, among other things, that the process of slicing or grinding timber into smaller and smaller particles has only increased its propensity to feed and foster fungi. The story of building material experiments over the past 50 years has been one filled with mold-growing and decay-filled results. This started with plywood, which in retrospect, seems a pretty tough material compared with its younger cousins, but is, in fact, far more vulnerable as a siding than, say, the redwood plank siding that was commonly employed for many decades leading up to the 1960s, until it was largely replaced by a range of variously checkered alternatives. 

When approaching a plywood-sided building, I general prepare myself to find soft, damaged siding in a range of specific locations. These tend to be just above trims that hold water, at the edges of trims where moisture will cling, and at the edge of almost any exposed panel. While plywoods vary in constitution along with paint quality and other conditions, there is no doubt that the material is quicker to foster decay and rot away than solid wooden planks.  

Part of the reason for this is that wood, like our own bodies, is built to resist infection, which is, after all, what we’re talking about. Trees are built up in layers of new wood as one way of preventing infection. Invading organisms have to first break through hard continuous layers—first bark, a layer designed to fail without hurting the tree, and then through various continuous multi-layered sheets of cellulose tissue. Our own skin is, similarly, our first line of defense against infection. Break the skin and in go those nasty microbes (including fungi, that in some cases hurt us just like they hurt our green leafy brethren).  

As soon as we start taking those nice solid boards, with their layers of resistant tissue, and begin slicing, dicing and grinding them up, their sweet delectable sugars are revealed to the fungal masses and you can almost hear the maître d’ calling “table for four million on the veranda!” (And they’re not eating at the table; they’re eating the table itself.) 

The worst case of this syndrome is the class of materials we might call particleboards. These have almost no defense, although various versions can have mixed success depending upon the protection that can be provided by chemical treatment or by mixing with various polymers. The first versions of pressed wood siding contained only a small amount of glues or resins and quickly found themselves the subject of large class-action product defect lawsuits.  

The industry has done well in eliminating these, but new troubled materials continue to emerge every day. While I like to save my sagest advise for my punchlines, I would say that, as a rule, it pays never to buy the first version of anything but to wait at least a decade to see what has turned out to be trouble.  

Now, Trex has been around longer than that, but it does turn out that there were lawsuits regarding the material as early as five years ago (at least this is as early as I’ve been able to find). A range of blogs I was able to find, as well as the findings of several local inspectors who I’ve chatted with, tell the story of decay in this material despite the early claims that this material, unlike regular wood, would be resistant to decay. 

Since I haven’t yet described what Trex is, let me take a moment. Trex is a composite material made from wood fiber (ground wood or sawdust) and plastic (mostly polyethylene plastic grocery bags). A number of other competitors exist but Trex would appear to dominate the market. 

Now, in defense of the product, I would like to say that I love the idea that manufacturers are making a useful product, such as decking material, out of all those store bags that we shouldn’t be taking home in the first place (and to Ikea’s credit, they recently started charging a small fee for those huge bags, and I believe this is intended as an environmental action rather than a commercial move). They’re also using wood fiber taken off sawmill floors, as well as grinding up pallets and pretty much any small wood scrap that can meet their requirements regarding contamination and wood type. This is all very green. The material itself is not particularly recyclable except toward making more of the same thing, but still, it’s wonderful we’re not just cutting down more trees. If the material were foolproof (and nothing can stand the test of a truly skilled fool), I’d be all the more excited. But, apparently, it’s not.  

Trex isn’t the only material you’ll want to watch closely in the coming years. Other WPCs (wood-plastic composites) such as TimberTech (potentially facing litigation) have turned out to produce what many a blogger (or attorney) describe as a range of problems including mold spotting, splitting or deterioration. Not to provide undue defense to these products, I do want to say that common wood, whether redwood or treated wood products, can have some similar problems, but the big difference is that virtually all makers of WPCs describe their products as being free from the problems that real wood tends to manifest.  

Redwood decking, just to take the other side for the moment, can have a long service life if well selected (redwood grades vary enormously from the pithiest juvenile stock to tightly ringed, dense, clear material that can least half a century on sun exposed decks) but poorly built redwood decks utilizing poor grades of lumber and poor detailing may show failures within 10 years. Redwood is also a fairly green choice since it grows quickly. California produces more than we can use and is a significant export for us. If we farm it carefully and avoid clear-cutting, redwood is a very reasonable (and I would argue, beautiful) choice. A range of hardwoods, including ipe, is also available for decking and many of these can be sought through sustainable farms if one shops smartly. Hardwoods tend to have a very long service life and require almost no maintenance if well installed, but are pricey. Woods, in general have some native advantages over WPCs, including greater strength (the ability to span greater distances for a given dimension) as well as reduced fire risk (most WPCs burn faster and hotter than equivalent wood, though new fire-retardant ones are available). 

A wood-plastic composite may be the right choice for you and allotments of defective material might represent a relatively small percentage of the total output, but this technology is relatively new and I don’t believe we’ve had enough time to study the life-cycle of this material to say with certainty what you’ll be getting when you buy. Products produced by large companies tend to get marketed heavily with little thought for future redress and the United States provides relatively little protection for consumers beyond the ability to sue when things go wrong. So it’s up to each of us to look around and consider how much we know about the new product before we lay our money down. 

If you have Trex, you may want to review the class-action suits by Hagens, Berman, Sobel and Shapiro website (e-mail address: trex@hbsslawcom) and Marc B. Kramer, P.C. There may be others if you look around. Accurate or not, they’re worth a look. 

When I look at really old houses (well, West Coast old) I’m often amazed at how well they’ve fared. Lacking a range of modern whiz-bang technologies, the simple time-tested methods often prove awe-inspiring, and real wood is certainly at the center of this. When people talk about “good bones” in a house, they’re not talking about ossified calcium; they’re talking about wood. And while the future of wood may bring us many efficient marvels made of chips and sawdust, let’s not forget how well we were served by the simple genius of a board cut from tree. 

ASK MATT 

Got a question about home repairs and inspections? Send them to Matt Cantor at mgcantor@pacbell.net.