Question: What steps should be taken during construction of our 800-square-foot wood-frame room addition to provide long-term termite protection? Also, what sort of precautions should be taken to make sure that the floor doesn't squeak after a few years--other than building on a slab?
Answer: Being concerned about termites is a good idea in California, where termite infestation is a constant concern (along with earthquakes, fires and high tides--for some beach folks!) You go on to ask about redwood and Wolmanized framing lumber, painting the wood and treating the soil.
Construction heart redwood, properly seasoned, is probably the best framing lumber around, according to a contractor I respect. It will cost about twice as much as the typical Douglas fir framing lumber used in most houses, but the peace of mind might be worth it. Many of the large old houses in Los Angeles and virtually all of the Victorian houses in places like San Francisco and Santa Cruz are framed in redwood.
The Wolmanizing method you mention in your letter is a proprietary treatment method from the Koppers Co. that preserves wood from rot and termites. It's one of several processes available. Wolmanized framing members are typically used where the framing sits on the foundation. Wolmanized sills and joists should be used in conjunction with proper treatment of the soil to keep termites out.