Can I exploit redwood as an alternative of strain handled lumber for my mud sills?
I’m usually requested this query, brief reply… Sure. However there is a motive only a few contractors use strain handled (or pt) redwood for mud sills and backside plates.
First let me say that I’ve renovated houses in neighborhoods in San Francisco and Marin that have been over 100 years outdated – constructed fully of redwood – and are nonetheless in nice structural situation. Certainly, redwood is of course wealthy in acids, which prevents rot and prevents bugs from consuming it, as a result of they’re the 2 worst enemies of the home, redwood has good sense. Till you have a look at the worth. The actual fact is that many areas of redwoods have been over-harvested and those who weren’t are actually protected. Because of this, the worth of redwood could be very excessive in comparison with different framing merchandise and they’re now utilizing youthful rising bushes which equates to extra knots, twists and wanes.
So to save lots of prices, strain handled lumber was launched as a wooden that would mimic the attributes of redwood however for half the fee. Stress handled lumber is often Douglas fir or typically fir hemmed and injected with many poisonous chemical compounds (copper or zinc napathane being the strongest). These chemical compounds are what stop rot and pest infestations, however they’re additionally identified to trigger most cancers by polluting groundwater when disposed of in landfills. In California, scrap items of pt have to be disposed of at a biohazard waste yard. Lately, toxin ranges have been lowered by approx. 50%.
It must also be famous that it’s by no means acceptable to lock untreated Douglas fir lumber in direct contact with concrete. There are a number of methods to deal with Douglas fir your self and make it proof against rot and pests. The #1 means to do that is to use copper napathane in a twig can or common brush-on liquid. You’ll find it at virtually any neighborhood ironmongery shop, however watch out when doing so! It can odor dangerous for a day or two, so do not apply it on to residing areas. Be sure you learn all manufacturing facility directions relating to the applying of any sealant or rot preventative.
So to reply the query, sure…completely, redwood is a good product for mud sills. But when you are going to use redwood, lower your expenses and get “tough lower” wooden, it is going to be barely bigger, so you will have to chop it widthwise, however the worth distinction is definitely worth the work extra.