DO-IT-YOURSELF : Take Stock of the Hard Facts on Wood Types
Whether you’re planning to build a wooden deck, fence, gazebo or furniture, or to freshen the ones you have, you should know about wood types and treatments before you buy the first board or slather on a cure-all coating.
Each type of wood recommended for outdoor use has inherent qualities that affect its appearance and resistance to deterioration. Identifying these benefits and weaknesses will extend the life and beauty of your wooden structures:
* Choosing wood: Redwood, cedar and cypress are varieties most often recommended for outdoor use. Redwood and cedar are naturally rot- and insect-resistant, and they weather to beautiful shades of gray. Each withstands some effects of weathering, such as warping, but will require periodic treatment to look its best. Cedar costs 10% to 20% less and is stronger than redwood, but it isn’t as tough as pressure-treated lumber.
* Pressure-treated wood: Fir, pine and other soft woods are sold pressure-saturated with preservatives that resist fungal decay and insects (especially termites). Pressure-treated wood is the densest, heaviest and strongest lumber you can buy, but it still needs protection from ultraviolet light and water damage. Some types are stained to resemble cedar or redwood, but most have a greenish cast that turns gray with exposure. Because it contains chemicals, treated wood needs careful handling and disposal. Consult your home center or lumberyard.
* Maintaining wood: A deck must be clean, dry and free of mildew before treatment. Mildew can begin growing after only 10 days, so new wood needs cleaning, too. Packaged deck cleaners and brighteners will remove dirt, mold and mildew. Some types bleach the surface to restore the wood’s natural color or to remove rust stains. Always follow the package directions and wear goggles, a mask and rubber gloves.
You can also clean and remove mildew from new wood using an equal mix of household bleach and water. Let the liquid sit for 10 to 15 minutes, then rinse thoroughly with water.
* Water repellents, or sealants: These liquids form a transparent barrier against the moisture that causes mildew, decay, warping and discoloration. Some repellents, also called sealants, contain ingredients to block ultraviolet light, which fades wood’s natural color to gray. Even pressure-treated wood needs help to combat the effects of water and sunlight. Ultraviolet light protectors can also be purchased separately. Repellents should be reapplied every year or so.
* Wood preservatives: Each formula fights a specific set of wood ailments, so check the label to make sure you’re buying just the benefits you need. In general, preservatives offer transparent protection against decay, rot, fungal stains, wood-boring insects and ultraviolet light. These treatments should be applied to all untreated wood every one to two years.
* Wood stains: Stains are designed only to color wood; they do not protect it against the elements and should always be used in conjunction with a repellent or preservative treatment. Formulas include semitransparent stains, bleaching stains for a weathered-color look and other products that accent the wood’s natural grain.
