Decks - All Sorts of Decks

Our love affair with "decks" is very understandable. Decks allow us to maximize the use of outdoor spaces. Decks expand our house size at a relatively low cost. Decks can help us take advantage of views, or protect our privacy. Decks reduce the amount of grass we have to cut. Decks are a great place for : the barbecue, the hot tub, flower pots, pets, kids, parties and construction problems.

Wood rot, water leaks, and slippery surfaces are but a few of the more common deck problems. Poor choice of materials and poor construction practices tend to make decks a source of constant repair and problems. But new materials and techniques allow the construction of decks which can be regarded as permanent structures with minimal maintenance.

For more information, you may want to take a look at the consult question and answers on Q&A: Decks.

Index

  • Our love affair with "decks" is very understandable. Decks allow us to maximize the use of outdoor spaces. Decks expand our house size at a relatively low cost. Decks can help us take advantage of views, or protect our privacy. Decks reduce the amount of grass we have to cut. Decks are a great place for: the barbecue, the hot tub, flower pots, pets, kids, parties and construction problems.

    Wood rot, water leaks, and slippery surfaces are but a few of the more common deck problems. Poor choice of materials and poor construction practices tend to make decks a source of constant repair and problems. But new materials and techniques allow the construction of decks which can be regarded as permanent structures with minimal maintenance.

    For more information, you may want to take a look at the consult question and answers on Q&A: Decks.

  • With the introduction and availability of pressure-treated lumber, wood decks have become more popular than ever. Pressure-treated lumber is impregnated with various types of salts which prevent wood decay. This type of lumber is available in various grades; from lumber that can be in contact with the ground, to appearance-trade lumber which can be used for the portion of the structure most visible.

    The use of pressure-treated lumber by itself is not enough to guarantee the quality of the deck. Well-built decks are characterized by the following:

    • 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 concrete pier blocks.

  • If the deck is fastened to the house, it must be flashed in a way that will prevent water entry to the house.
  • 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.
  • 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.
  • Pressure-treated lumber will tend to crack if not coated with a water sealer. The water sealer should be applied at the time of construction, and subsequently every 3 years.
  • Decks built with non pressure-treated lumber, including decks built with cedar, require periodic treatment with a wood preservative. Old growth cedar "heartwood" lumber has a relatively high resistance to rot. But most of the cedar we find in the lumber yard is relatively young "sapwood" and will start to rot in a few years unless it is treated at construction time and every 3-5 years hence. Even if you find and can afford top-quality cedar, the application of a wood preservative will help protect your investment, and a quickly disappearing wood product.

    Materials avaialble at Dunn Lumber.

    • Remove soil and debris located within 6" of wood members and re-grade the soil to prevent future soil/wood contact.
    • Inspect the entire deck for any lumber damage from wood rot, insects or weather.
    • Any damaged lumber should be replaced. If possible, pressure-treated lumber should be used (it may not always match the look of the rest of the deck).

  • Next, a pressure washer should be used to get rid of the moss and debris caught between the deck boards. A pressure washer can damage wood if used improperly; special care must be taken with soft wood, like cedar.
  • During the wood preservative application process, soil and vegetation around the deck should be covered with plastic to prevent the wood preservative from destroying the vegetation.
  • The wood preservative can be applied with a brush or roller after careful review of the instructions that accompany the particular product.
  • In addition to treating or sealing decks, it may be necessary to remove moss and mold from deck surfaces. Full-strength liquid bleach will do that job quite well, as will some of the specialty products advertised for that purpose (most contain bleach). A more environmentally-sound solution is the use of the less toxic products designed for moss removal. Most lumber yards and garden stores stock a selection of moss removers.

  • 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.

    The Household Hazards Information Line telephone number is (206) 296-4692. Similar services are provided by local agencies in many other parts of the country.

  • When I drive up to a home with a waterproof deck I know that some very special attention will have to be payed to the parts of the house associated with that deck. Most roofing products are not intended for foot traffic and can be easily damaged by improper use. Over the last few years, a number of decking materials intended for foot traffic have been developed and successfully used to build decks that also act as a roof.

    Waterproof decks require the very best construction practices and the most careful attention to detail. 'B+' grade work is all too likely to fail and cause damage to the structure of the property. Once a very good quality waterproof deck is installed, it requires a re-coating every 5-10 years.

    The most commonly used product is a self-vulcanizing Hypalon, which is available in several brands and in several colors. This product, like most decking products, must be installed on new, high quality, untreated lumber -- most commonly, "A"-grade plywood. The installation of this material is not very forgiving. Careful attention to the installation instructions and details is mandatory. Once properly installed, it is long lasting, can be recoated with an identical product, and will withstand normal home use.

    Other waterproof decking products are available on the market; many are specialty products installed by an authorized agent of the manufacturer.

  • Among the deck products with lowest maintenance costs are concrete, concrete paver and ceramic paver decks and patios. The material itself will withstand most weather conditions, does not rot, and burning pieces of charcoal will not cause it to burn.

    A good concrete or tile deck will last if:

    • It is built on a solid foundation. The soil around a newly built house will tend to settle unless it has been compacted. Even when built on compacted soil, a patio will tend to settle differently than the house. It may be necessary to connect the patio or deck to the foundation.

  • Expansion joints of wood, rubber, or asphalt must be built into the concrete in order to allow for controlled cracking. Old wood expansion joints tend to rot out, and may have to be replaced with treated lumber.
  • Not all clay products are intended for outside use, some will absorb a great deal of moisture and crack or flake as the moisture freezes. Even masonry intended for outside use benefits from moisture proofing every few years.
  • Concrete does not have to look dull and gray. It may be colored by use of various additives, colored sand, and specialty aggregate. The top layer of the concrete can be "washed off" during installation, producing an "exposed aggregate." A good place to see some alternative uses of concrete is Chuck Greening's "gate" at the northwest corner of the Good Shepard Center on 50th North and Meredian in Seattle.

  • 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 on GFI's.

    In building a deck, careful attention must be given to the proximity of the deck to existing electric lines and other electrical equipment.

  • A deck may not require a building permit if it is less than eighteen inches off the ground. Most decks must comply with all zoning requirements, such as lot coverage, side yard and back yard setbacks; as well as structural and other building code considerations.

  • Many decks feature a roof for sun and rain protection, built from materials other than normal roofing materials. Corrugated and other fiberglass roofing work fairly well and require a minimal slope, but will deteriorate in three to five years due to the ultraviolet rays of the sun. Similar effects can be seen with other plastic materials.

    Awnings are made from a variety of materials. Standard canvas deteriorates after a few years. The vinyl-impregnated variety tends to last longer. Many of the retractable awnings use a woven synthetic material which tends to have a somewhat longer life than most of the other awning materials.

  • 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 plant cultivators are specifically selected 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. Treating the wood deck after the climber has grown for a few years could be difficult without damaging the plant.
  • Our decks will be in their full glory as company comes from out of town. We will try to 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 Puget Sound population explosion.