I’m in the process of tearing down the two-story deck behind my house. The posts, railing, and decking are redwood. The rest is pressure treated.
The deck was built when the house was, in 1980. The posts were simply buried directly into the ground.
I’m tearing it down for two reasons. It has to be removed to provide access to my foundation which has settled and will be jacked up. It’s also a crappy, dark, and ricketty design, with the second story shading the first.
As I’ve pulled it apart I’ve found serious insect damage. Trails beginning at the posts lead all thoughout the structure, wherever a path could be eaten without breaking the exposed surface. There are no bugs to be found, but the deck and surrounding area was treated for termites at some time in the last 5 years. I’ve owned the house for three.
So was it termites that ate through my redwood? I didn’t think anything was supposed to eat redwood.
There is no sign of carpenter ants either.
4DThinker
Replies
4D, no wood is impervious to insect damage. I have some carpenter ant damage in my treated pine deck (Detroit area.) They've literally hollowed out the core of some of the deck boards which had not absorbed enough of the chemicals in the treatment process.
In your case, it could be either termites or carpenter ants, depending mostly on where you live. What they were and what they did to your deck is an interesting academic question...But I think the more practical question is; where did they go? Hopefully, the previous owner got rid of them when the deck was last treated, but I wouldn't count on it. You might want to inspect the studs and joists in your house...especially along the wall that faced the deck.
Edited 6/4/2003 7:43:45 AM ET by Jon Arno
What makes fresh redwood somewhat insect resistant is the tannic acids in the wood, As these leach out over the years the redwood becomes as good a host as any for the bugs. If your posts where direct burial without being set in concrete this may have happened sooner than expected.
I have heard that old-growth redwood like we used a hundred years ago was insect resistant naturally. I don't know if it is true but i was told that the redwood of today is grown commercially and is actually a hybrid that is not all redwood. It is mixed with some other type of tree that grows faster. Maybe someone has some more knowledge about this and would share.
ddessert, they may be planting genetically improved redwoods these days as a result of hybrids or simply careful selection within the species...but the bigger issue is the maturity of the trees. As a tree grows, it transports extractives via the wood rays toward the center of the tree and stores them in the dead vascular tissue in the heartwood. These extractives are often antiseptic and give the heartwood greater resistance to decay...and in some species, also greater resistance to parasites.
In fact, the sapwood of many species, which are known for the excellent decay resistance of their heartwood (such as most of the "cedars", baldcypress and some hardwoods) has very little decay resistance. For example, the sapwood of western redcedar is less decay resistant than is the heartwood of pine.
Just another piece of trivia...but, while the old-growth giant redwoods take literally millennia to reach full maturity, redwood actually regenerates very quickly and is not a diffucult species to manage in reforestation. It is somewhat site sensitive (demands consistent, coastal moisture), but it grows quickly during the sapling stage. The major western species that is in greatest parrel due to over harvesting these days is western redcedar. It regenerates much more slowly...and at our present rate of logging, we will exhaust our reserves of this species well before the middle of this century...and we'll be waiting the better part of a century before second-growth WCR attains adequate maturity for its heartwood to become durable as an exterior construction timber.
Naturally occuring decay resistance is more than a function of the presence of tannins but is more likely due to other organic compounds which do more than render the wood antiseptic but are in fact quite toxic biocides. Included among these types of chemicals are alkaloids, gylcosides, saponins, phenols, catecols, quinones, stilbenes, terpenes and furocoumarins. These compounds can be produced by the trees themselves or in some sort of symbiotic relationship with another organism (as with taxol production in Taxus species).
Distribution of these chemicals is not entirely a result of flow in wood ray pathways but is also a function of diffusion (following some concentration gradient) through intercellular pit pairs of the solublized substances.
Heartwood is also not entirely homogeneous regarding the distribution of extractives. Juvenile wood has less decay resistance which often accounts for decay around boxed heart pith. Additionally drying practices, even including certain air drying practices as well a certain kiln schedules and the process of steaming (to attain a more uniform color distribution) can significantly reduce decay resistance.
It is also necessary to state that decay resistance is not entirely a function of age. Genetics, reaction to stress, site conditions and competition all effect extractive concentration and distribution within the wood. And it is a well known fact that the location of the wood within the tree is an additional factor -- the general rule being that the farther the wood is from the center and from the tree base, the lower is its decay resistance.
It should be recognized that natural (and often artifically induced) decay resistance does not preclude all types of insect infestations of wood. There are those organisms (such as carpenter ants) that use the wood only for habitat and do not ingest or use the wood as a primary food source. As such, they can create tunnels in wood and remain unaffected by the otherwise toxic substances.
The lack of qualitiy Western red cedar, both presently and for the future, is a real problem in the Pacific Northwest. In many instances, to attain a suitable regeneration rate for reforestation, much higher seedling planting rates (#/acre) are required when compared to Douglas fir. Thus for short term economic advantage, many companies harvest the WRC and instead of replanting WRC opt instead to convert the land to a Douglas fir monoculture. And it is also well known that hooved browsers such as deer and elk, forage on young WRC so it is often necessary to do a secondary planting (which likewise increases reforestation costs and therein further decreases a company's short term profits).
And Jon, based on your less than precise spelling within your comments, please refrain from ever again criticizing me for my inadvertant mistakes.
Stanley Niemiec
Wood Technologist
Stanley, don't leave me hanging...What did I misspell?
Jon,
"parrel" should be "peril" -- I must say, though, I think you write quite well myself. An occasional ooopsie is acceptable.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
That's one of 'em. "Diffucult" was the one that tipped the scales.
Anyway, I got to give a little light-hearted payback to Jon for the hardtime he gave me when I too hurried wrote Umbellularia californica or something similar. You know we have to stomp out all forms of liberalization and we might as well start with spelling. But that could them be a real problem for Dan Quayle!!
Now Stanley, you're harboring a grudge. The only reason I nailed you that one time when you misspelled a half dozen or so botanical names is I was defending my terf. I specialize in misspellings and grammatical errors and I don't take kindly to anybody muscling in on my territory.
"But that could them be a real problem for Dan Quayle" Just to be a thorn in the side, is this supposed to be "then"?!? hehehe
Getting back onto the subject at hand, my parents home is made of redwood, and they have problems with Carpenter bees. Evidence of this is seen via a 1/4" entry hole. Bees dig in and lay eggs, etc. My father always said it was because redwood is soft and the bees think its easy work.
Carpenter Bee hunting was great fun for us as kids.
I'll be dipped, forestgirl...I think you're right. But then, I have a somewhat hostile attitude about spelling anyway. Conventions, like spelling, strike me as little more than an extention of political correctness...and I don't have much use for anything Liberal.
One of these threads, we'll have to get into the art of communication. As you might expect, I'm highly opinionated on that subject, too. I think modern English is suffering through the final stages of rigor mortis. Our language hit its high water mark during the Age of Discovery (about the time of Shakespeare.) since then, it's succumbed to a sort of insidious centralization...Doubtless there's a Liberal at the bottom of this plot.
Ain't it just like one of those blankity, blank darn conservatives to say that the good old days and ways were the best and that with any new idea is another nail in the coffin of glorious civilization. Methinks some of these ye olde fogeys might opt for a return to the Latin of Imperial Rome! Maybe not to that point, but I seemed to remember a rather vociferous uproar coming from the Right when Eubonics was suggested as an alternative method to improve literacy among certain minorities
But alas there is a more pressing problem relative to the wood strength vis a vis growth rate that needs to be clarified.
"Old growth tree are much closer together and much tighter foliage, causing a slower growing tree. Smaller growth rings means stronger lumber ..."
Edited 6/4/2003 8:51:15 PM ET by NIEMIEC1
Stanley, what's "eubonics"...is that that flea vectored plague that hit Europe in the 14th century?
Fleas and rats! And likely, as it was from the Middle East, an early example of Muslim terrorism and WMD. So who's oil fields can we now conquer to prevent such reoccurance and so we can make the world safe for all the little old ladies in North Dakota?
Fleas and rats! And likely, as it was from the Middle East, an early example of Muslim terrorism and WMD. So who's oil fields can we now conquer to prevent such reoccurance and so we can make the world safe for all the little old ladies in North Dakota?
ROFL!!!
That's a tough one, Stanley. Both Libya and Iran have enough "crude" to make it a real toss-up...But I'm more interested in your tip about that over abundance of "little old ladies in North Dakota"...You suggesting I should get up there while I can still get around without a cane?
Stanley,
It's Ebonics, as in ebony. Sheesh. Not to worry; it's not botanical.
Cheers,
Greg
To add on your comments of old growth vs. new growth, the major factor is in the densities that the trees are grown. Old growth tree are much closer together and much tighter foliage, causing a slower growing tree. Smaller growth rings means stronger lumber along with your previous statements. New growth redwood has the capabilites of growing rings at a rate of 3/4" per year. Not allowing for much late growth, which is the strongest part of each growth ring.(I hope I got the early/late growth part right- I'm confused).
This is the same thing that is happening to all woods. Faster growth, larger growth rings, weaker lumber. One of the main reasons why lumber calculations keep changing over the years. Then again, another discussion has been borne. "Changes in the engineering load calculations of lumber" :-(
While your assumption may seem logical and that relative to mechanical properties (eg. bending strength), it is in fact incorrect.
It is a pretty complex subject with several counterintuitive considerations.
If you are talking about very young trees (implying that there is a very high percentage of juvenile wood) then yes the wood is less strong.
However many wood strength properties are directly correlated to wood density and therein trees that have higher percentages of the more dense latewood (aka summerwood) tend to have higher mechanical property values. In very tight growth (with >16 rings per inch) Old Growth Douglas fir, the amount of earlywood (springwood) may be equal to that of the latewood. However when you get into wood that has three or four growth rings to the inch, the latewood percentages increase dramatically.
For example, there were changes made in allowable design load values when second growth Douglas fir became more prominent in dimension lumber units and more of the Old Growth was going towards non-structural moulding and millwork applications. But now that the Douglas fir is being harvested on shorter and shorter intervals (40 to 60 year instead of 60 to 80 year) the higher percentage of juvenile wood is forcing a lowering of design values.
Remember there is not necessarily a direct correlation between appearance grade, and strength.
Stanley Niemiec -- Wood Technologist
Migraine, the relationship between rate of growth and strength is species specific. In some woods, such as ash, rapid growth produces stronger wood, because it lays down a wider band of denser latewood. This is why second growth ash saplings are the preferred stock for making ax handles. You're right, though, with respect to most softwoods, where wider spaced annual rings generally result in weaker wood.
"What makes fresh redwood somewhat insect resistant is the tannic acids in the wood, As these leach out over the years the redwood becomes as good a host as any for the bugs. "
I always thought so as well, until a friend of mine had a very large redwood (5' diameter at the base) cut down after it was damaged in a storm and threatened his house. When it was cut up, you could see how the tree was ravaged by termites from below ground to about 6' up. No doubt, this is what precipitated the tree's failure.
The first thing that comes to my mind is sapwood. Much of the redwood sold for the past several decades has a large percent of sapwood which ain't rot resistance like the heartwood is. Check your post for white wood if possible, could be all gone by now.
My brother was putting on new fascia (sp) boards some 15 years ago, and paid a premium for redwood, IT WAS 60% sap! The industry gets away with this because the general public does not know better, all they know is redwood is good.
We've had some problems with redwood outdoor furniture being eaten by a golden retriever. Fortunately, he's graduated from puppyhood!!
Redwood is the absolute gourmet wood of choice for my two golden retievers. The only thing that they like better are the insulated electrical control cables going to the central air unit in the middle of summertime.
Back to the original question - I have seen those large bumblebees bore into fairly fresh redwood and create tunnels and havoc.
Ed
Sound like termites. Ants tend to "hollow out" wood, sometimes leaving the growth rings. Take a pic and post it. No wood is impervious. "From dust we were made and to dust we will return". That goes for Redwood too. Good Luck!
John
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