Wood Decks


  • Pre-historic people lived out of doors most of the time and got along without decks. On hikes in the mountains or at the seaside we get along just fine without decks. A cleared area, a flat rock or a log can serve as a fine place to rest or share a meal. "Roughing it" can be a lot of fun but it has its limitations. Decks can have many advantages over make-shift outdoor locations. For example:

    • Their location can be selected, decks can take the best advantage of views, the weather, proximity to the house and yard.
    • Decks can have nice flat areas that accommodate furniture, planters and BBQ's.
    • Properly built decks can be easy to clean and maintain (less sand in the food!).
    • Decks can enhance a home, they can be part of the "architecture" of the house, they can extend the living space, they can make interior spaces look and feel larger.

    I love decks and have made sure that they are an integral part of my own home. I look forward to the warm weather when we open the doors onto the deck and thereby extend the living (and dinning) spaces into the yard. But I also enjoy our decks during the cold weather when the decks provide a visual extension to our home.

    A raised wood deck

    A raised wood deck

    Photo courtesy of our sponsor EB-TY® Hidden-Deck Fastening SystemsTM.

    Our decks are raised wood decks like the one in the photo above, but there are many styles of decks:

    Patios - Low to the ground surfaces made out of various types of stone, masonry or wood. Balconies - Cantilevered extensions to upper floor rooms (made popular by Juliet). Roof Decks - Flat roof surfaces that are designed as an outdoor living space (hint - this is a very demanding type of construction).

    There are many materials that can be used in the construction of most deck styles. Wood is one of the most popular.

  • It seems that whenever I drive by one of the "box-store" lumber yards I find a small "demonstration deck" by the front door and a sign promoting the low price of the materials and the ease of construction. And I have little argument with either claim. Decks can be relatively inexpensive projects and they can be a relatively easy construction project. This leads many of us to shop and build first and design later, I know, thats what I did with my first deck in 1971.

    But even the least expensive deck uses costly material and many hours of labor. And all decks require some maintenance. Good design and planing can help you:

    • end up with the deck you want and like,
    • know if this is a do-it-yourself project or one requiring a contractor,
    • stay on budget,
    • choose the right materials, and,
    • reduce maintenance requirements.

    A good place to start is to look at some nice illustrations of decks, look for ideas and make some lists of preferences.

  • I love collecting urban myths and some of my favorites involve building and construction. The issue of permits, codes and zoning are the subjects such myths. Some tips regarding zoning, building codes and decks:

    • building officials are busy and are very unlikely to monitor your home just because you asked questions about a deck,
    • so, ask questions, lots of questions and ask them early, (I have learned a lot from building inspectors),
    • most permits for decks are relatively easy to secure (and don't require an act of congress), they may require some plans but you will want these plans in order to have a good design,
    • most building departments have some very good and free information about all types of construction work and a lot of that is on-line,
    • a deck may not require a building permit, for example, if it is low to the ground, and,
    • most decks must comply with all zoning requirements, such as lot coverage, side yard and back yard setbacks.

    Building permits can take some time and cost a little money but have many advantages:

    • Permits "force you" to think out the project before your build (I wish that I would have done that when I built my first deck in 1971).
    • The permit process and related inspections can help you make sure that your contractor is building the project safely and per plans.
    • A deck built to code is a better selling tool when you get ready to sell your home.

    So, call your building and zoning departments early in the planing process. Ask lots of questions. Ask if they have some information about decks and permits for decks. Find out about the time it takes to get such a permit.

  • The use of wood in deck construction has become more popular with the introduction and availability of various types of weather and rot resistant lumber. Such products have made deck construction and maintenance easier and less expensive than before.

    Wood rot and weather resistance depends upon the type of wood used and its applications. Some of the wood choices available on the market include:

    • Cedar and Redwood - These two domestic wood varieties have a greater natural resistance to wood rot and to some insects than most wood varieties. These are relatively soft woods, are easy to work and are often used for deck surfaces, railings and trim. But they are not magic. I can show you homes with exterior cedar and redwood surfaces that are over 100 years old and the material is in perfect condition. But poor quality and/or improperly installed and maintained cedar and redwood can start to rot in a matter of a few years.

    The use of cedar or redwood in decks requires careful selection of material. Young sap-wood material may have very little resistance to rot. Old heart-wood material has much better resistance to rot but is hard to find and quite expensive. But no matter how good the quality of the cedar or redwood, decks made out of these materials will require frequent treatment with a wood preservative.

  • Treated Lumber - Treated lumber is impregnated with various types of rot resisting chemicals. Most of the material sold today is treated with chemicals that have a relatively low toxicity. There are various types of treated lumber. Some are designed for the most demanding areas, those with ground contact. Others are smooth surfaced and designed for deck surfaces and other visible locations - "appearance grade" products.

    Treated lumber can last for decades with relatively little maintenance and repairs. The decking should be coated with a penetrating finish in order to reduce wood cracking. Pieces that are cut or shaped during the construction maybe subject to wood rot damage in the areas where inner/untreated sections of a board are exposed. And this decking, like almost all others may have to be pressure washed and treated for moss in order to keep the deck from becoming slippery.

  • Ipe - Ipe is a tropical wood that is being imported from South and Central America and has a high level of rot resistance. It is usually used as the decking surface over a structure of treated lumber.

    This is a relatively new lumber product on the market. It seems like a very promising and low maintenance product. But I do suspect that even Ipe will succumb the our Seattle area rain and have to be cleaned and treated in order to prevent it from becoming slippery.

  • Composite "Wood" - This is not a wood product. It is a manufactured material, often made out of recycled plastic bottles. Trex(tm) is one of the better known brand names. Composite wood decking is often used as the decking surface over a deck structure made out of treated lumber. It is gray in color and not a paint able or stainable surface.

    Composite wood can be worked with most wood-working tools. Its heavier per unit than the other options and bends more easily. As such, it may require closer joist spacing. I have seen many decks and outdoor public structures made out of composite woods and have been impressed with the results. I have also seen two decks with surface damage produced by the paws of the family dog - I have no idea if or why that might be a common problem.

  • The use of rot and weather resistant lumber by itself is not enough to guarantee the quality of the deck. Well-built wood decks are characterized by the following:

    • A good, but not necessarily complicated foundation - A deck may not need a foundation as hefty as that of a house, but it does need a good foundation. The best foundations for decks tend to be poured concrete footings with metal post saddles. Small decks or those low to the ground can be built on pre-cast concrete pier blocks.
    • A stable structure - Every year come the stories of collapsed decks. This is often the result of inadequate fasteners at the ledger boards that connects the deck to the house or inadequate lateral bracing. Ledger boards must be bolted to the house and all above ground decks must have some lateral support.
    • Engineering? - Larger and taller decks, decks on hillsides, decks with hot tubs and more complicated deck structures may require some engineering work. How big is big? and when is an engineer required? don't be afraid to ask. A preliminary consultation with an engineer will most likely cost very little and the total cost of the engineering a small faction of the total cost of the project.
    • Flashing - If a deck is fastened to the house, it must also be flashed in a way that will prevent water entry behind the siding and into the wall structure.

  • Hardware - Nails and other fasteners, as well as flashing, joist hangers and hardware must be resistant to water and weather. Under normal conditions, hot-dipped galvanized material is a good choice. If your deck is near salt water, you may want to use stainless steel.

    The Hidden-Deck Fastening SystemsTM from our sponsor EB-TY® come with their own stainless-steel screws, and create a beautiful, safe and durable deck surface.

  • Soil-to Wood Contact - Some pressure-treated lumber has the capacity of withstanding soil contact for 40 years and more, but it will most likely last longer if it is kept out of the soil.
  • Wood preservatives and pressure-treated lumber may contain toxic substances. Instructions must be read carefully. Pressure-treated lumber should never be burned. Gloves and protective clothing and disposal of excess material and debris according to regulations is mandatory. For folks in the Seattle area, the Seattle/King County Health Department can answer any specific questions.

    Similar Household Hazards Information Line services are provided by local agencies in most parts of the country.

  • The current electrical code requires that receptacles on decks be protected with a ground fault interrupter (GFI). Hot tubs and spas that use electricity are also required to be protected in this manner.

    In building a deck, careful attention must also be given to the proximity of the deck to existing electric lines and other electrical equipment. For example, a new deck built onto an existing structure can interfere with the location of the electrical meter base and may be too close to the power lines.

  • Planting areas on decks are a major cause of wood rot, but when properly built and maintained can be trouble free and add to the enjoyment of the deck. Year-round water and soil are a must in planter boxes, mandating even more careful selection of construction techniques. But planters also need to overcome some of the special challenges of deck gardening:

    • The small volume of earth in most planters will tend to require frequent watering. Daily watering is usually required in mid-summer.

  • Many gardeners recommend that you plant one pot inside of a larger pot with moss or other water-retaining material to keep more constant moisture levels.
  • Drip irrigation systems make deck gardening less of a watering chore.
  • Some plants are specifically recommended for decks, including "patio" tomatoes, and other "bush" varieties.
  • Herb gardens are ideal for decks near kitchens.
  • Clematis, grapes and wisteria, as well as other climbers are ideal for "softening" deck structures and trellises. But vines must be kept away from the siding of the house. They can damage the siding, provide an easy path for pests and even grow into the framing of the structure.
  • With a bit of planing our decks can be in their full glory as company comes from out of town. We will can then assure our guests that not every summer morning allows for a leisurely breakfast in the sun. And if a bald eagle or heron flies overhead, we will have a ready opportunity to talk about the fragile environment, Hershel and his friends, and the population explosion.