Aluminum decking has several advantages over wood, composites, and pvc (all -plastic). It will definitely last longer and require less maintenance, perhaps no maintenance. Aluminum extrusions also have structural strength that composites do not have. This means you may be able to build your deck with joists that farther apart and still have a stronger deck.
Aluminum decking is an aluminum extrusion with a profile similar to the above illustration. It is very lightweight as well as strong. (This illustration is a close but not perfectly accurate representation. It is intended only to explain the concept.) Aluminum will, of course, never absorb moisture, and it will not warp.
You have the option of choosing an extrusion that will link the “planks” together in a way that makes the deck waterproof. This is not the only type of decking that can keep the space under your deck dry, but it is a natural solution.
And if you are extremely healthy and manage to outlive your deck, aluminum is never wasted in the recycling chain.
There are some disadvantages though. For one thing, it is more expensive, costing up to two times what a composite deck would cost. While the companies that make aluminum decking offer it in a range of pleasing colors, they make no attempt to make it look like wood. It will look like aluminum. It should be no surprise then that you are more likely to see aluminum in a commercial than residential setting.
A new method was developed in the 1940’s that used a chemical mix known as CCA for Chromated Copper Arsenate in a pressure treatment process that pushed the chemical into the grain. This made softwoods such as Southern Yellow Pine resistant to rot, and insects.
In December 2003, the pressure treatment industry in the U.S. stopped using CCA for wood that would be used in residential applications such as decks and picnic tables. Why? The chemicals might be good for wood, but they are very toxic to humans, and as a nation, we are becoming more careful to avoid poisoning ourselves. Ending the use of CCA in lumber was like taking lead out of gasoline and paint. In recent years, wood for residential projects has been treated with more benign chemicals such as Micronized Copper Azole or Alkaline Copper Quaternary (ACQ) or Sodium Borate. I don’t pretend to understand what these chemicals are, but they are apparently much less toxic than CCA.
Not all treated lumber is the same. There are levels of pressure treatment, and they are graded AG for above ground, GC for ground contact, and GCS for in-ground applications. in the meantime, wood is still being treated with creosote and CCA for commercial applications.
Concerns about the toxicity of treated lumber have fueled the growing popularity of alternatives such as composites, PVC, and aluminum. Everything we humans do or make has some kind of impact on the environment. We need to be aware of this and just try to choose the best options. Plastic alternatives to wood have an impact during their production, but then they are inert and stay around a long time. In many cases the material can be recycled.
Despite the popularity of composite decking, pressure treated wood is still very widely used. For one thing it is much less expensive. And, for the most part,composites are not used for the structure of a deck. You need the fiber strength of real wood. (A couple of companies have developed a structural composite, but its use is not widespread.)
Home Depot has a page with good information about treated lumber on their web site. It points out that the ACQ/CA (Copper Azole) treated wood tends to be darker in color and retain more moisture when you buy it, while the MCA treated wood tends to be drier. You need to make sure the wood is completely dry before you apply paint or stain. The way to know wood if dry enough to paint is to drop some water on it. If the water absorbs, the wood is dry enough. If the water beads up and doesn’t absorb, then it needs more time to dry out before you try to paint it.
Home Depot also says that “Ground Contact” as a rating of treatment is generally recommended. Wood rated Ground Contact has twice the preservative level as the Above-Ground rated wood.
Home Depot says “when used properly,” modern pressure treated lumber is “both safe and environmentally friendly.” However they also say that pressure treated lumber should never be burned because of the preservatives, and you should wear gloves, eye protection, and a dust mask when working with it. Screws or nails need to be hot dipped galvanized or stainless.
Over the past 75 years or so, we have gone from giving little or no thought to the risks chemicals pose to health and the environment to …. perhaps… being overly cautious. It is confusing. We have to go with the current advice of the experts and hope we are making the best choices for our families.
Now we have a new problem: how to dispose of old pressure treated wood in ways that are safe for humans and the environment. It turns out to be very tricky issue. You can’t burn it because that releases arsenic into the atmosphere. You can’t dump it in a landfill because that releases arsenic into the soil and ultimately the water table. The only really proper method is landfills with liners. States and local communities have not yet addressed this issue with a consistent set of laws, but regardless of what is allowed or not allowed where you live, it is something to worry about.
There is the option of returning to old fashioned construction and build outdoor projects with untreated wood… then just paint it every couple of years, but not, of course, with lead paint. This is actually my preference if I am using wood in an outdoor application. One reason is that I have some old pressure treated boards and “landscape” timbers at the back of my yard because I don’t know how to get rid of them. I know I don’t plan to purchase any more treated lumber.
We are not claiming that DeckProtect™ is the only way you can enjoy a fire pit on your deck, but it does seem to be the only solution that is designed specifically for the purpose… the only one that is both effective and convenient, and the only solution recommended by Trex. (page about Trex recommendation) As with any other topic, you need to be skeptical about what you read online. Not all advice is good advice.
I think of porches as being old fashioned and representing a traditional life style. However, according to a 2014 survey, 76% of home builders said that new homes are likely to include a front porch. http://eyeonhousing.org/2015/05/what-builders-are-building/
I may not have read it right, but in any event, along with granite counter tops, walk-in closets, and "great rooms," front porches are in. They are believed to add "curb appeal" and therefore value to a home. A front porch might be a small structure for the front door, or it might be a larger space where you could hang out and watch the world going by. But if you want to spend relaxing time reading a book or chatting with friends, do you really want to be in the front of your house where all passersby can watch you? So some people say that the difference between a deck and porch is that the deck is usually on the back of your house, but in reality a porch or a deck could be anywhere depending upon how you want to use it and on the surrounding landscape.
So what is the difference between a porch and deck? The simple answer is that a porch has a roof, and a deck is open. A deck is for outdoor living, and a porch is somewhere in between outdoors and indoors. You can sit on a porch and watch the rain come down. A porch will have columns or posts to support the roof, adding to a semi-indoor feeling. You can add screens to the side of a porch to keep insects out in summer. A porch floor is more like an interior floor with no space between the floor boards. Porch furniture can be more like indoor furniture. And if you are considering adding a porch to an existing house, you will find it much more expensive…. naturally, because of the roof.
You would never use a wood-burning fire pit on a porch, but you might use a gas-burning fire table…. in which case you would want to take certain precautions such as having a DeckProtect under it to protect the flooring.
Photo credit: Khongit Wiriyachan 123rf.com
The build is very inexpensive and easy to do. You need six 2x3's eight ft long. Cut three of them in half with a 30 degree angle. and cut each end with a parallel angle. Each 2x3 cut this way will be a basic X.
Then, using 2-1/4" or 2-1/2" screws form three X's with 15" in the top section of the X. Cut additional sections of 2x3 to double up the lower part of each leg and screw them on. This will guarantee that no branch or heavy log will be too heavy for the jack to support. When you buy the 2x3's pick up four or five 8-ft. furring strips… 1x3" x 8'. These are very cheap and crude lengths of wood that will serve well crossing each X near the bottom and then connecting the three X's together. When you have your three super-sturdy X's take them to your back yard and connect them in a row using furring strips and screws. You want the first two a little over 3 ft. apart and the third X about 11 or 12 inches from the second one. This way you can support long or short branches or branch sections as you cut.
The next thing you need to do is…. sorry … wait a year before burning the wood in your fire pit because burning green wood generates a lot of smoke to get in your eyes. After a year or so, or longer, the wood will have dried out fairly well.
Here is the strange thing about regular window glass. It fails to reflect even more heat than asphalt … 91%. (high thermal emissivity of .91) because the solar heat passes through it. This is why traditional home builders in New England wanted more and bigger windows on the sunny side of the house, at least in the Winter.
So what does this have to do with composite decking?
Azek, maker of composite decking, wants you to realize you may encounter a problem if you have windows and doors with specially made Low-E glass. This is glass with a micro coating that reflects most of the heat while not obstructing light. It is a high tech way to make thermally insulated glass to keep an interior space from heating up in the summer or from losing heat in the winter. A house with sliding glass doors opening on to a deck has a large glass surface perpendicular to the deck surface. Sunlight with its thermal radiation hits at an angle and could reflect directly onto the deck’s surface… except that with regular window glass, 91% of the heat passes through into the kitchen. Low E-glass would reflect the heat onto the deck, and that is the concern.
An Azek technical bulletin specifically warns customers about E-Glass in "AZEK Building Products Technical Bulletin #060310 Effects of Excessive and Unusual Heat Sources on AZEK® Products:
This is by no means a criticism of Azek composite decking. Excessive heat from Low-E glass is potentially a problem for composite decking made by any manufacturer. We applaud Azek for making customers aware of the issue. Unlike Trex, Azek does not specifically warn its customers about using a fire pit on a composite deck. They probably assume you are already concerned about that. It should be noted that Azek decking meets exacting building codes for heat and flame resistance.
The Azek bulletin refers the reader to the Vinyl Siding Institute web site where I found the following FAQ items on a page about “Concentrated Solar Reflection.:”
"Is the damage from solar reflection and heat distortion limited to vinyl siding?
No. Other materials can be raised to temperatures known to cause short-term or long-term damage from exposure to intensely concentrated sunlight. Anything that falls in the path of that reflected beam can be harmed including cups, bags, pool covers, car parts, painted surfaces, and cedar shingles are a few of the materials reported in the media to have been damaged. People who have found themselves in the path of such beams of have reported extreme discomfort and the inability to remain exposed for more than a few seconds without enduring the risk of burns. Eye damage from even a brief exposure is highly likely."
"Does this happen only in the summer, or only in hot climates?
The phenomenon can occur anywhere the sun shines, in any season. Even when the air is cool in winter, if the sun’s energy is concentrated onto a small surface area, that location can become far hotter than the surrounding area. But in many cases the relationships of the angle of the sun, the direction of the window and the location of the house wall are “just right” only at certain times of the year."
"Can the high temperatures created by concentrated sunlight set my siding on fire?
No. The ignition temperature of vinyl siding is approximately 720-750 °F (380-400 °C). This is well above any temperatures reported to have been caused by even the most extreme cases of concentrated sunlight reflected from windows. In fact, the ignition temperature of wood is lower than that of vinyl siding, so wood materials such as siding, fencing or decking would be at greater risk of ignition than vinyl siding."
What does vinyl siding have in common with composite decking? Vinyl.
While Trex is a very well known brand in composite decking and the leader in the industry, there are many other brands, made by a number of different companies, and made of different combinations of materials. Generally, composite decking is a board made of basically sawdust and a binding agent and covered with a thin layer of plastic. I don't believe that the word "sawdust" is used in the industry. You will also almost never see the term "plastic" used. The terms used are PVC or HDPE, etc. which are acronyms for their chemical components, typically, but not always recycled from plastic bags and soda bottles. It is the (plastic) outer layer that has the color and the faux wood texture. It is also this layer that is most vulnerable to heat damage. Each manufacturer will use its own formulation of the HDPE or PVC, so they are not all the same. Often, but not always, the manufacturer will promote the particular qualities of its proprietary formula that make its brand superior. We have been doing a lot of research into the composite decking industry and will be sharing it with our readers over the coming weeks.
Fire tables are more and more popular with homeowners. Not without good reason; they have a lot of advantages and great features. All of the fire tables we have seen burn gas, not wood. This means you don't have to buy or cut firewood, and there is no clean up. They also have a certain elegance about them that you don't get with a wood-burning fire pit. When you have really nice upholstered deck or patio furniture, a fire table fits in nicely. While you would not expect the relatively small flame from the gas fire to generate as much heat as a raging wood fire, the heat tends to get trapped below the burn area. Most fire tables have enclosed case-like structures. They look great, but there is nowhere for the heat to go… so it builds up. And this is where you could run into a problem for the surface underneath. In some cases our square DeckProtect will fit your fire table well. In many cases the fire table will be rectangular, not square. The solution is to simply measure the length and width and then go to our custom sizes page to place your order.
For cooking and staying warm, we don’t need fire, but for our spiritual comfort, perhaps we do. I am old enough to remember a world, not only without cell phones, but also without TV. My family had a TV for about two of my growing up years. It was a big box, bought second-hand, that had a fuzzy black and white image. Most of my youth was free of television. We spent our time doing other things, playing outdoors, building models, making things, reading, playing monopoly, building forts in the woods, and a lot of very special time gazing into a campfire or fireplace. Looking back, I remember a rich childhood, lacking nothing really.
I think the popularity of fire pits has something to do with reconnecting with our basic human nature.
This photo is a stock photo from www.123RF.com. When I used parts of a Christmas tree to start a fire, I was jumping back, not taking pictures. So this tip for fire pit enthusiasts is also a cautionary tale for anyone setting up a real tree for Christmas. We have always heard that Christmas trees are a fire hazard, but I, for one, did not understand how absolutely explosive this combustible material can be. I hope that everyone will be very careful with their tree at Christmas, especially when it starts to dry out. And if you do decide to save some branches for your fire pit, please store them as safely as you would store gasoline.