Outdoor garden furniture can greatly enhance your yard, patio, or deck, but furniture kept outdoors is constantly being attacked by rain, sun, and freezing, as well as by insects looking for a free lunch. Some woods are better than others at standing up to all these environmental stresses. It is important to select appropriate wood types when building outdoor benches or furniture if you want your project to last.
The most important factors to consider when choosing wood for an outdoor project are:
- Resistance to decay and insects.
Decay is caused by fungus getting into the pores of the wood. Some woods are much more challenging for the fungi to get into and cause rot. Woods such as cedars, cypress, white oak (but not red oak), redwood, teak, ipe, and iroko are very resistant to decay. Some woods are particularly unappetizing to insects (such as: cedar, redwood, teak, and padouk). It is also important to keep your outdoor benches and other furniture out of direct contact with the ground. Natural resistance of a wood to rot and bugs is a characteristic of the heartwood, not the sapwood, of a particular species. The sapwood is always less resistant and requires protective finishes to withstand water or insects.
- Weather resistance.
No wood can withstand moisture and sunlight without damage though the more durable woods will last longer than others. The real solution here is to keep your outdoor furniture out of direct sunlight and to use a protective finish on any furniture that is left outdoors. The finish will need to be renewed periodically when needed (approximately annually).
Wood prices vary greatly and change often based on availability and geographical location. Pressure treated lumber is usually the least expensive (though also the least attractive) wood to use for an outdoor project. Redwood, cedar, and cypress are often available at reasonable prices. Tropical hardwoods (such as: teak, ipe, iroko, etc.) can be prohibitively expensive. Many tropical hardwoods are becoming more and more rare and therefore more expensive. Inquire at a local lumberyard to see if the wood you want is available and if you’ll need to take out a second mortgage (not recommended!) to buy enough for your outdoor project.
- Sustainably harvested.
An important factor in the harvesting of wood in the world today is whether it is being done in a responsible and sustainable (and legal) manner, or using exploitive methods that are contributing to the depletion of the world’s forests (especially the rainforests). We all need the forests for the health of the planet and, therefore, ourselves, so it makes sense to buy wood (especially exotic woods) from sustainably managed forests. To find out if the wood you’re buying comes from such a source, search for retailers that sell FSC-certified wood or find more information by going to the Forest Certification Resource Center’s website.
Rather than choosing a naturally durable wood for your outdoor furniture project, you could choose pressure treated lumber, which has been impregnated with chemicals to make the wood decay and bug resistant. Pressure treated wood certainly has it’s uses, but may not be the best choice for furniture that is in direct contact with people since the wood is usually green, has a tendency to warp, and brings up concerns due to the use of toxic chemicals. Pressure treated wood is also not as attractive as many types of wood. However, pressure treated wood is almost always the least expensive type of lumber that is suitable for outdoor use.
Whichever type of wood you choose, your project will last longer if you use a protective finish on it, keep it out of direct sunlight, and out of contact with the ground.