QUESTION: I am building several outdoor projects with pressure-treated wood. I've been told that the wood should be stained. I was under the impression that pressure-treated wood would last in its natural state for years--just the way it comes from the lumber dealer.
ANSWER: Outdoor or pressure-treated lumber is treated with chemicals to resist decay and insect attack. This procedure permits the consumer and forest industry to make use of inferior grades of lumber, rather than increasing the demand for redwood, cedar or cypress. But unlike species of timber that are naturally decay- and insect-resistant, these lesser species have more pronounced grain and are more prone to splinter and crack than redwood or cedar. So, even though the wood is treated, it is best to apply a stain--or at least a water repellent--as soon as your project is dry enough.
The first tip for working with pressure-treated lumber is to let it dry before using it. Other woods such as redwood and cedar are dry when you buy them. But lumber that has been treated has been injected with massive amounts of chemicals and water. For wood that will be in ground contact, these liquids penetrate the wood completely.
If possible, handpick your own wood at the lumber dealer. Select lumber that looks straight and true and is lighter and drier to the touch. These pieces have less water content and will be ready to use sooner. For very heavy lumber, understand that the extra weight you feel is fluid weight and will evaporate in time. Stack wet lumber on a flat surface such as a driveway or patio, use spacers between boards to let air circulate and check the wood for weight and by touch for moisture. We have let pressure-treated lumber sit for four or more weeks in 90-degree weather until it was dry enough to use without shrinking.
When the wood is dry, it may be too hard to nail. Pre-drill holes for nails to avoid splitting the lumber. Use construction adhesives and metal connectors to reduce the number of nails or screws needed. Use only galvanized nails or coated screws for assembly.
Apply stain or water repellent to the "down" side of the lumber before you nail it in place. Joists, braces and the underside of deck boards will be hard to reach and finish when you have nailed them in place.
Asbestos Ceiling Should Be Enclosed or Removed
Q: I am concerned about a possible asbestos problem in our ceiling. Our home was built around 1969, and it has a type of ceiling finish known in this area as popcorn, which contains asbestos. The ceiling has become dirty and needs to be repainted. Can the ceiling be repainted or should it be dealt with by some other means?
A: First, have the ceiling material tested to see if it contains asbestos. Just because asbestos was used for ceilings at the time your house was built doesn't mean that your ceiling contains asbestos. Testing is recommended because of the expense involved in properly correcting the problem if the ceiling contains asbestos. If it does, then whatever action is taken is not a do-it-yourself task.
The procedures for working with asbestos-containing materials fall into three general categories: removal, encapsulation and enclosure. Painting would be considered encapsulating. However, prior to painting, the ceiling would have to be cleaned. This can cause particles of asbestos to loosen and fall.
Also, several asbestos consultants with whom we discussed this problem recommend against encapsulating a ceiling because they were concerned that the weight of the layer of encapsulating material would cause the "popcorn" to loosen and drop from the ceiling.
The decision for removal of the popcorn or enclosing the ceiling is one that should be made by a certified asbestos abatement consultant. Abatement companies can be found in the Yellow Pages of the phone book. Most abatement companies offer a free estimate.
It's important that you correct the asbestos problem, and not only for your own health. If you ever intend to sell the house, the asbestos ceilings could become a negotiating item.
To submit a question, write to Popular Mechanics, Reader Service Bureau, 224 W. 57th St., New York, N.Y. 10019. The most interesting questions will be answered in a future column.