Replies

1. 
   Dale | Sep 01, 2004 12:38am | #1

   Live oak is durable outside, but can be a pain to work, I've been told??  Whereas water oak is a red oak and it not very durable...Dale

2. 
   Jamie_Buxton | Sep 01, 2004 01:10am | #2

   As I understand it, the live oaks are in the red oak group.   The red oaks have open pores.   (You can blow spit bubbles through a short section!)  The open pores mean that water enters easily, and the wood doesn't do well outside.  In contrast, white oaks have closed pores, and do well outside.  Water oak, I dunno.  We don't have it around here.

1. 
   tdh_2002 | Sep 01, 2004 04:50pm | #3

   Live Oak was used to build ships in the 1800's (http://boston.about.com/cs/history/a/USSConstitution.htm).

   More info on oaks courtesy of USFS at http://forestry.about.com/library/silvics/quercus.pdf 

2. 
   jonsherryl | Sep 01, 2004 06:06pm | #5

   Jamie, the term "live oak" refers to the tree's habit of retaining foliage...in other words, the live oaks don't follow the deciduous pattern of losing their leaves in the fall and going into a state of dormancy. They constitute species that are basically tropical and subtropical in distribution...but they include both members of the red oak and white oak groups.

   Our primary Eastern live oak; Quercus virginiana, is a member of the white oak group, but there are many live oaks, especially in Mexico, that belong to the red oak group.

   As you mentioned earlier, the red oaks and white oaks differ, in that the white oaks tend to produce tyloses in their pores. These are baffle-like structures that act to restrict the passage of moisture and, therefore, limit the wood's porosity. This improves decay resistance by keeping the wood's moisture content below the level required for fungi metabolism (below about 20%, if the wood is used above grade and prevailing environmental conditions allow the wood to maintain an Equalibrium Moisture Content that is comfortably below the 20% cutoff).

   The red oaks tend to have large, open pores that allow the wood to take on moisture more quickly in rain storms...but even the red oaks are not defenseless against decay organisms...in that, like all the oaks, they contain high levels of tannic acid, which is antiseptic...But the whites have the additional advantage of maintaining a more arid and inhospitable internal environment for molds and other fungi.

   Edited 9/1/2004 11:10 am ET by Jon Arno

1. 
   Jamie_Buxton | Sep 02, 2004 01:35am | #8

   Jon --

     Thanks for the info on live oaks.   I'd often wondered whether the trees called live oaks here (California) are the same trees as the ones called live oaks in Texas or Florida.    Evidently not!

     Jamie

1. 
   jonsherryl | Sep 02, 2004 06:17am | #11

   Jamie, We have over 50 species of oaks native to the U.S. alone...but only a handfull of them  are "live" oaks and they are distributed throughout our southern states, from coast to coast.  Mexico, with about 120 species leads the world in terms of numbers of oak species and the majority of them are live oaks. So. while we have perhaps a half dozen or so species of live oaks, Mexico has perhaps as many as a hundred...and there are even a few more tropical species further south in Latin America.

3. 
   Jimma | Sep 01, 2004 04:59pm | #4

   Water oak rots in a year if unprotected and splits like crazy. I wouldn't recommend it for anything in the South. Jim (in Orlando)

4. 
   MarkRoderick | Sep 01, 2004 07:35pm | #6

   From visiting Boston, I know that ships used to be made from what they called "live oak" so I imagine it's pretty good in water. The problem, as someone mentioned, is that live oak is incredibly hard to work. It took lots of men with axes to cut it down. That is the sum of my knowledge on the subject.

1. 
   jonsherryl | Sep 01, 2004 08:57pm | #7

   Mark, the primary reason for the use of live oak in the construction of 19th century American warships (Old Ironsides, etc.) was it's extreme density...and therefore, it's ability to take a pounding from cannonfire. In shipbuilding of that era, the primary means of redusing decay and maintaining water tightness was the application of naval stores, i.e., pine resins, which resist moisture and are also antiseptic.

1. 
   Jimma | Sep 02, 2004 03:25am | #9

   Also, Jon, with live oaks in the South, especially those with a good deal of age, there are already many branches reaching great lengths and having naturally bent shapes which lend themselves to hull designs without the need for shiprights to bend them -- sort of naturally pre-bent. This also gives great strength to them for use as stringers, ribs and the like. Today I used a chain saw to remove the outer portions of some live oak. The amount of interlocking and twisted grain was amazing. I don't have the foggiest idea what I'll do with it if I can get it to dry OK, but the creative juices are flowing.

   Imagine what it'll be like after Frances!

1. 
   Portugee | Sep 02, 2004 05:21am | #10

   Thank you all once again for all your help.

   It looks like the flavor of the month is live oak.

   Sergio

   "Portuguee" woodbutcher in Orlando,Fl.

2. 
   jonsherryl | Sep 02, 2004 06:23am | #12

   >>'I don't have the foggiest idea what I'll do with it if I can get it to dry OK, but the creative juices are flowing."

   Jim, Lotsa luck getting branch stock to dry without checking and distortion...Especially with this species. Given all the reaction wood found in branches, the meandering grain direction and the heavy rays, it's probably going to twist every which way but loose.

1. 
   Jimma | Sep 02, 2004 03:19pm | #13

   That's OK, Jon, all I have to do is match the twisted grain with my twisted mind.

5. 
   lwj2 | Sep 04, 2004 10:47pm | #14

   Unless you're stuck on oak for a wood, you might want to take a look at cypress.

   While it's in the category of soft wood, it's pretty rot resistant. Lots of docks got built in Tidewater VA when I was a kid using cypress.

   Leon Jester, Roanoke VA