Outdoor Wooden Structures: Materials for Fences and Decks

As well as featuring in the hard landscaping of many gardens, wooden structures are also commonly used to create fences as well as decorative features in the garden. All wood must be treated if it is in contact with the ground. Wooden structures can also be stained, varnished or painted.

Wooden Garden Materials

Wood can be used to build garden structures such as fences, features or decking. Wooden structures can be combined with masonry or metal components for decorative effect, extra strength or ease of construction. Kits are often available for you to construct fences or other projects, or you can use ready-made components such as sawn wood, posts and brackets to create your own design using basic woodworking joints.

Fence Considerations
Most fences need a gate. These are usually hung between two fence posts. Some open fences, such as split-rail designs, can be given a mesh backing if you need a barrier for animals.

Fence Types

There are several traditional designs of fence often used as boundaries or screens within a garden design. Some have panels or boards placed between posts to form a solid boundary, while other designs are more open, being simply constructed of vertical and horizontal members. When choosing a fence, consider how well it will fit with the style of house and garden, and what level of security and privacy you require.

Close-Board
A solid fence built from separate components, easily adapted to your specifications. Overlapping vertical wooden slats are attached to horizontal rails (arris rails) running between fence posts.

Picket
Similar in construction to a close-board fence, this decorative, partially see-through fence has gaps between the uprights. The uprights may be rounded or pointed for decorative effect.

Split Rail
A simple, open design. Horizontal members run between posts. Wire mesh can be used across the framework to provide a less penetrable barrier if necessary. The mesh is attached to the posts and rails using staples.

Fence Posts

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The type of fence post you use will partly be determined by the type of fence you are constructing. In domestic gardens, wood is the most common material used, although metal and plastic posts are also an option.

Square Wooden (Image 1)
A simple design that can be made from a variety of different woods.
Square or rectangular in cross-section

Round Wooden (Image 2)
Can be used to provide a more rustic appearance than a sawn, square post. Often used with half-round horizontal members in a split-rail fence.

Metal Posts
These are good choices for chain-link and plastic fences. Make sure you use standard sizing in order to avoid the laborious process of having to cut the metal posts.

Putting in Posts

Excavate a hole for each post, approximately 24 inches square and below the frost line to allow for infill around it (Image 1).

Pack crushed stone into the base of the post hole (Image 2).

Fast-setting concrete should be poured in the base of the hole and allowed to cure for 24 hours before refilling the hole with dirt (Image 3).

Fence Accessories

There are a number of fence accessories that are used to aid installing and help repair these structures. The brackets and clips shown below provide a few examples of the types of systems that are available.

Post Caps
Decorative caps attached to the top of wooden posts. Also prevents water penetration into the end grain of the posts.

Gothic-Style Plastic Post Cap (Image 1)

Wooden Post Cap (Image 2)

Post Clip (Image 3)
Small clip that screws to post and fence panel, holding the panel in place.

Bolt-down post bracket (Image 4)
Socket that houses a post on concrete or other masonry surfaces.

Square plastic post cap (Image 5)

Wooden Walkways and Decks

Wood is also used underfoot in yard construction for paths and steps, as well as patio areas. Decking has become increasingly popular as an alternative to hard-landscaped areas.

Cedar Decking (Image 1)
Durable and versatile, cedar decking has a color range from light browns and tans to salmon pink. It does not transfer heat, so you can walk barefoot no matter the temperature.

Pressure-Treated Decking (Image 2)
Primarily due to cost, pressure-treated is the most popular choice of deck materials in the U.S. About 80 percent of pressure-treated wood is Southern yellow pine. It usually has a warranty against decay and termite damage.

Composite Cecking (Image 3)
Composite decking is made up of a combination of wood particles and plastic. It can be embossed with a wood-grain pattern. Typically the color will lighten over time. Consider buying one that contains preservatives.

Vinyl Decking (Image 4)
If you live in a hot climate, vinyl can get very hot underfoot. It is more expensive than wood, but it requires less maintenance. Cutting vinyl is just as easy as cutting wood. It does not absorb stains.

Erecting a Fence

To lay out a fence, secure a string line with pegs at the starting and finishing point of each straight run of fence. If you are using manufactured panels, it is best to plan the length of the fence so you can use whole ones. With other types of fences, it is easier to adjust the design to your specifications. Once you have marked positions, it is a case of installing posts to the required depth and filling in the fence.

Post Holes

It’s best to determine the locations of post holes for a fence by locating the center of the hole. Mark that location with a nail so you can find it. Use a garden spade to dig a hole 12 inches square. Make the post hole a shaft straight into the earth with a flat bottom. Most fence post holes should be 2-feet deep. If your post height exceeds 8 feet, however, a good rule of thumb is to make the hole one-quarter of the total length of the post.

Planning the Fence

Once you have marked the run of the fence with a string line, you need to work out the post spacing. The distance between posts will vary according to fence type. For a panel fence, the distance is governed by panel size, which is commonly 8 feet. A similar distance may be used for close-board fences, although this can be adjusted depending on the type of boarding used. Fence posts can be set in concrete, or held in place by steel brackets, straps or post anchors on a concrete surface. When a fence is positioned on or next to a wall, the posts may be bolted directly to the wall, so there is no need for an attachment at ground level.

Securing Posts

Once the post positions have been marked out, the next step is to dig post holes. Alternatively, you can drive in or bolt down post sockets. If you are digging post holes, a 6-foot fence will need posts secured in holes approximately 24 inches deep and 12 inches square. The holes will need concrete poured in the bottom. Use pressure-treated wood for the posts that will have ground contact. They can then be secured with concrete.

Erecting a Panel Fence

Fence panels can be nailed into place, but brackets give a neater finish. You need to make sure that the bottoms of the panels don’t touch the ground — they must never sit in standing water. You can use gravel boards below the panels. Alternatively, as shown here, install fence panels so that they are slightly above ground level.

Screw clips to post, one at the top, one in the middle, and one at the bottom of the post (Image 1).

Slot the edge of the panel into the clips and secure it in place (Image 2).

Further Information

Always contact your local building official and homeowner’s association prior to building any outdoor structure. There are guidelines and regulations on a variety of issues ranging from material to depth of post holes.