Is It Necessary to Treat a Cedar Fence?

Cedarwood

• True cedars (genus Cedrus) grow in the Mediterranean region and the Himalayas. This group of trees includes the biblical cedars of Lebanon, which reportedly were used in building King Solomon's Temple in Jerusalem. In North America there are no native, true cedars. Instead, several types of conifers are commonly sold as cedarwood, though to botanists these trees differ slightly from the true cedars of the Old World. Often called "false cedars," the wood from the North American cedars is red, highly aromatic and shows good resistance to insects and decay. American trees commercially sold as cedarwood include the Western red cedar (Thuja plicata), the Atlantic white cedar (Chamaecyparis thyoides) and the Eastern red cedar (Juniperus virginiana).

Installing the Fence

• Correct installation of the fence can ensure that an untreated fence lasts many years. The most significant trouble area is contact with the ground. Only the fence posts should be in contact with the ground, and the life of a fence post can be extended by packing gravel around the base. Always use a water-resistant wood (cedar, redwood or cypress). You may want to add a preservative to the portion of the post that rests in the ground. Finally, a small gap placed between each vertical slat will prevent moisture from accumulating between the boards.

Local Climate

• Local climate affects the life of a cedar fence. Such an outdoor structure will survive better in a dry, arid climate than along the wetter temperate zones in the Pacific Northwest and east of the Mississippi River. Even so, a properly installed cedar fence in these areas should last a long time, even without the addition of preservatives.

Treating the Wood

• Cedarwood can be stained for decorative reasons. According to Tim Carter of the Ask the Builder website, it is best to use a transparent stain that contains synthetic resins and no natural oils, because the natural oils will attract molds and mildew. A cedar fence infested with mold or mildew should be cleaned with oxygen bleach, a green product, allowed to dry thoroughly and then treated with a preservative containing synthetic resins.