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The boards under your feet ain't what they used to be.
All decked out
The boards under your feet ain't what they used to be. But which one is best?
Kevin Burnett, Special to The Chronicle
Saturday, July 9, 2005
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Summer means lounging around outside on the deck, and those who don't have decks may think about building one. First, before the tools come out, you need to decide what type of material to pick for your deck. Should it be redwood, cedar, pressure-treated wood or perhaps one of the many brands of faux wood on the market? Each has its pros and cons.
Decking manufacturers touted their wares at the Pacific Coast Builder's Conference last month at Moscone Center in San Francisco. Makers of faux wood decking as well as representatives of the redwood and cedar industry were there, eager to explain why their product is best.
Wood or plastic?
In today's market there are two dominant categories of decking. Wood is the traditional choice. It looks great, particularly when first installed. It's cool to the touch on hot days, unless you happen to step on a screw head with your bare feet.
Wood polymer composite, a mixture of wood fiber and plastic, is the new kid on the block. Composites are touted to be almost maintenance free, long lasting and exceptionally durable.
Wood continues to dominate the market, but composites are rapidly making inroads, and now hold about 18 percent of the market, according to Bryan Peterson of Trex, a company that makes composite decking.
The most common wood decking material used in the United States is pressure-treated lumber. As much as 80 percent of wooden decks are built with such wood, which has been infused with chemicals to make it unpalatable to termites and other wood-destroying organisms.
However, the government has been recommending that industry phase out chromated copper arsenate (CCA), a carcinogen and the dominant chemical used to produce pressure-treated lumber. The rise in the popularity of composites is directly related to the anticipated ban of CCA.
A survey commissioned by composite-deck retailer GeoDeck found that composite-decking sales increased 198 percent from 2000 to 2004 and that the expected annual growth rate of the industry from 2004 to 2009 is expected to be 23 percent.
Lots of players
With the increased popularity of composite decking, several companies have begun manufacturing it. . Among them, in addition to Trex, are TimberTech, Louisiana Pacific, Epoch and CorrectDeck. Each of these manufacturers were present at the builder's conference.
Wood polymer composites are a combination of plastic and wood fiber, combined under heat and pressure, and extruded into boards. The process requires wood fiber, plastic pellets and a big, expensive machine. The wood fiber is dumped into one hopper and plastic pellets in another. The two components are mixed in a third hopper, then run through an extruder system under heat and pressure. Out the other end come deck boards. Composite boards are uniform, dense and, according to the manufacturers, durable.
In the early 1990s, a division of Mobil Oil, seeking a way to recycle petroleum-based waste, introduced one of the first composites. Mobil soon afterward sold the operation to four ex-Mobil executives, and the company became Trex.
Peterson said Trex decking is made from 50 percent hardwood "flour" and 50 percent stretch polyethylene film. Ninety percent of the film used is recycled.
Like Trex, other firms manufacture composites consisting of wood flour and polymer. According to spokeswoman Jennifer Jenkins, Louisiana Pacific's composite decking is 60 percent wood flour and 40 percent polyethylene.
Martin Grohman, founder and president of Correct Building Products, says CorrectDeck also contains 60 percent wood flour, but the plastic component is polypropylene, which he claims is significantly stronger than polyethylene.
"Polypro is a step up, like oak over pine," Grohman says.
Strength remains a challenge for the industry. Composites, unlike wood, are not structural members. Although they have great compressive strength, they lack tensile strength. In other words, it takes a lot to crush them, but they bend easily. As a result, composite boards cannot be used for deck framing. Instead, composite decking is installed on standard pressure-treated wood posts, beams and joists.
Warranties for composite decking range from 10 to 25 years. But, like a chain that is as strong as its weakest link, a deck will last only as long as its weakest component. Even though composites are long lasting, a deck will need rebuilding when the framing fails -- most likely before the decking itself needs replacing.
Workability
Composite decking boards are installed by attaching them to wooden joists either by screwing through the face of the deck boards to the joists using joist-mounted deck hardware or, in the case of one product from CorrectDeck, a hidden fastener system attached to the top of the joists.
No special tools are necessary to install composite deck boards, and the uniformity of the boards adds to the ease of installation. A circular saw with a 24-tooth carbide-tipped blade is used to cut the boards.
Because the material is harder than redwood or cedar, a pilot hole must be drilled into the board before it can be screwed to the joist.
Although this step increases installation time, it prevents the board from splitting, especially at the ends. The fastening pattern is the same as for wood, two fasteners at each joist.
Composites react to fluctuations in temperature rather than moisture. To prevent buckling, a quarter-inch gap is required midway and at the end of each board.
Peterson of Trex points out a unique feature of composite decking: Because they are largely made of polymers, boards can be bent and formed into fabulous designs.
Wood's good
If you're looking for the beauty of natural wood in composite products, you're barking up the wrong tree. Although manufacturers have made great strides since the early '90s, composites simply do not look like wood.
Redwood and cedar are niche players, with redwood having about 5 percent of the market, according to Charlie Jourdain of the California Redwood Association. Cedar has about 7 percent of the market, according to Cees de Jager of the Western Red Cedar Lumber Association.
Traditionally, redwood is used on Bay Area decks. More recent options are cedar or exotic hardwoods like Ipe (EE-pay, from South American forests) or ironwood.
When asked why someone would build a wood deck rather than a composite deck, de Jager surprisingly said a big reason was ease of maintenance. He said that if wood is allowed to naturally age, there is no difference between maintaining a composite or cedar deck. Just wash them both every so often and clean off the debris.
So, what's it cost?
At $2 to $2.75 per linear foot, wood polymer composites are more expensive than either redwood or cedar. Manufacturers say consumers will ultimately save money because they won't have to re-stain the boards.
Redwood and cedar prices vary by grade and species. According to Jourdain, construction heart-grade redwood should cost about $1.50 per foot for 2-by-6 decking. Cedar is less expensive at $1.15 to $1.30 per foot, according to de Jager.
Grohman of Correct Building Products sees the future of decks -- and it isn't wood. "Just as no one drinks their soda out of glass bottles anymore, there will come a time when the notion of having a wood deck will be 'nostalgic' or 'antique.' Composites will improve to perform better, and homeowners will want that."
Which is greenest?
Mirror, mirror on the wall: Who's the greenest one of all?
Manufacturers of wood polymer composite advertise the environmental friendliness of their products.
After all, they say, we're taking garbage in the form of waste wood, plastic bags and plastic milk jugs and turning it into useful woodlike products. They claim their product is made with a sustainable resource -- plastic.
To some degree their claim is valid. Depending on the manufacturer, each composite board contains 40 percent to 93 percent recycled material. All wood fiber used in composite decking is recycled. Wood waste from furniture mills, golf tee makers, tongue depressor makers and others is ground into wood flour, then added to the polymer.
Trex uses the most recycled material, with more than 90 percent of its decking consisting of waste plastic and wood. Approximately one-half of the polyethylene used by Trex comes from recycled shopping bags. So the next Safeway bag you toss could end up in your deck.
CorrectDeck has created a synergy between itself and the U.S. Postal Service. According to Martin Grohman, his company buys much of the "polypro" used in CorrectDeck from the USPS in the form of worn-out plastic letter totes.
But composite manufacturers ignore one key point in their quest for environmental friendliness. Composites are not biodegradable. Fifty years from now, having fallen out of favor or having been replaced by a better product, much of the composite decking of today will be obsolete and will end up in landfills. It will not degrade and, instead, will join the plastic milk jugs and plastic bags from whence it came.
Wood, on the other hand, is biodegradable and sustainable. Bird-dogged by federal, state and local government, redwood and cedar manufacturers make every effort to be good stewards of the land.
According to Cees de Jager, the cedar industry is tightly regulated by the British Columbian government, which requires that three cedar saplings be planted for every tree harvested.
Charlie Jourdain echoes de Jager. The California redwood industry is highly regulated, with site-specific cutting subject to federal, state and local controls. Manufacturers are also required to replant areas that are harvested.
"Production of redwood is limited by environmental factors," Jourdain says. "We are providing it on a sustainable basis and can only sell what we can grow, and that's limited."
So, the greenest of them all appears to be -- wood.
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Tackling the material question: natural or not?
Making a decking choice is tough. Below is a table that may assist in guiding your decision.
Composites are not maintenance free, but they are low maintenance when compared to wood. Cleaning the deck once or twice a year with a bucket of soapy water and a bristle brush, followed by a squirt from the garden hose, will clean away most dirt and debris.
The composite industry is busy working to solve three inherent problems. The rap on composite decks has been that they are susceptible to mold, they fade and they stain. In each case, the wood fiber is the root of the problem.
While mold has been an issue in the past, manufacturers now are adding mold inhibitors in hopes of alleviating this problem. In any event, a yearly cleaning should go a long way toward preventing mold.
The biggest downside for most composites is their propensity to stain. Imagine the inaugural party on your new deck and a bowl of pasta salad accidentally goes flying and lands in the middle of the deck. Wood fibers soak up the oil, and there you have it -- an almost impossible to remove stain. Sanding is not an option because that will mar the deck. Cleaning with commercial deck cleaners may lighten the stain. The best solution remains to clean it up as fast as you can and live with it.
At least one manufacturer, CorrectDeck, is attacking all three of these problem areas. According to Marty Grohman, a protective layer of colored polypropylene is "double extruded" on CorrectDeckCX. It totally encases each board, is mold and mildew retardant and is impervious to stains. If a composite with a "painted" look tickles your fancy, this may be the way to go.
A table comparing decking choices: * GeoDeck claims their decking is less susceptible to fading. By incorporating a proprietary product they call "biodac" in their formula, fading is reduced.
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CHART:
Wood/Polymer Composites
Longevity: 25 year warranty
Environmental Factors: Uses from 40 percent to 90-plus percent recycled materials. Non-biodegradable.
Maintenance: Low
Cleaning: Annual -- clean with bristle brush, soap and water.
Mold/mildew: Most products are manufactured with mold inhibitor.
Fading/Color Change*: Will fade 7 to 10 percent after installation.
Staining: Will stain. Sanding is not recommended.
Looks: Approximates wood. Embossed wood grain on many products.
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Redwood/Cedar
Longevity: 15 to 25 years (depending on location and proper maintenance.)
Environmental Factors: Biodegradable. Contributes to reduction in mature forest lands, but reforestation mitigates the effect.
Maintenance: Low, if left to age naturally. High, if stained and sealed. Requires re-staining every two to five years.
Cleaning: Annual -- pressure wash with deck cleaner.
Mold/mildew: Will develop mold in wet areas. Treat with weak bleach solution of deck cleaner made for mold removal
Fading/Color Change*: Will age naturally. Original color can be revived by use of deck brightener containing oxalic acid.
Staining: Will stain. Can be sanded. Can be re-stained or allowed to age naturally.
Looks: Natural wood appearance. Ages well.
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Pressure Treated with Chromated Copper Arsenate (CCA)
Longevity: 10 to 15 years
Environmental Factors: Contains arsenic, a known carcinogen.
Maintenance: Medium
Cleaning: Annual -- pressure wash with deck cleaner.
Mold/mildew: Will develop mold in wet areas. Treat with weak bleach solution of deck cleaner made for mold removal
Fading/Color Change*: Original green color will fade.
Staining: Will stain. Can be sanded.
Looks: Greenish color initially. Will develop checks and cracks over time.
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CorrectDeck CX
Longevity: 25 year warranty
Environmental Factors: Uses from 80% to 85% recycled materials. Non- biodegradable.
Maintenance: Low
Cleaning: Annual -- clean with bristle brush, soap and water.
Mold/mildew: Manufactured with mold/mildew inhibitor.
Fading/Color Change*: Resists fading.
Staining: Dense, fully encapsulated, double extruded finish. Will not stain.
Looks: Seemingly painted finish.
* GeoDeck claims their decking is less susceptible to fading. By incorporating a proprietary product they call “biodac” in their formula, fading is reduced.
E-mail Kevin Burnett at sweatequity@sfchronicle.com.
