|

|
Questions?
Enter keywords in search box below:
|
|
|
|
Dry Rot Damage & Treatment in Wood
-
Rot caused by a "wood-eating" fungus -
|
Summary:
Dry rot is a condition of wood in which a fungus
breaks down the wood fibers and renders the wood
weak and brittle. Excess moisture is the
root cause of dry rot. Borate
wood preservatives can be used to treat and
prevent fungal growth in some situations.
Jack DeAngelis, PhD
OSU Ext. Entomologist (ret.)
|
|
|
Dry
rot is caused by a fungus
Dry
rot (see photo at right) is a weakening of
wood caused by one of several species of fungus. The
fungus digests the parts of the wood that give the
wood strength and stiffness. Weakened wood is
typically somewhat dry, hence the name dry
rot, and brittle (see photo).
Ironically,
dry rot usually results from too much moisture
in contact with wood. The dry rot fungus has
the unusual ability to transport water from wet
areas to dry areas allowing the fungus to grow even
in relatively dry wood. If not stopped the dry rot
fungus will so weaken wood that it may eventually
disintegrate.
|
|
|
Dry rot damage to
structural wood. Photo by Clemson University
- USDA Cooperative Extension Slide Series.
|
|
|
|
|
Damage
may resemble ant or termite damage
Dry
rot is often confused with carpenter ant
or termite damage. Carpenter ant damage
(see What are
Carpenter Ants?) is distinguished by the removal
of wood and formation of clean cavities
where the carpenter ants live. Subterranean
termite damage is similar to dry rot in overall
appearance but the presence of live termites,
termite galleries and generally wetter wood
will usually separate the two conditions (see What
are Subterranean Termites?).
|
|
Preventing
dry rot damage
The
most important way to prevent dry rot damage is to reduce
or eliminate excess moisture. This may be
as simple as repairing a leaky pipe or as complicated
as stopping water infiltration through a basement
foundation. A common cause of dry rot and termite
damage is wood in contact with soil as occurs, for
example, with a failed foundation.
If
moisture cannot be controlled, or if the dry rot
fungus as gained a foot-hold, then wood should be
treated to inhibit the growth of the fungus (see
below). Boric acid, or borate, is an
excellent fungicide (a pesticide that kills
fungi) against the dry rot fungus. Borate also
prevents insect damage. Wood can be treated during
construction, during repair, or as a remedial
treatment to stop an active infestation.
|
|
|
|
Borate
wood preservatives are generally applied as liquids
with some type of sprayer. Because
borates are water soluble
they should not be used where liquid
water
is present. In wet situations use fused
borate
instead because it is made for exterior
applications. Fused borate is often used to protect
log ends in log homes (see Protecting Log Homes From
Insects and Dry Rot)
and wood utility poles against dry rot.
|
|
Treating
dry rot
Treating
dry rot is a three step process. Step
1 is to locate and stop the source of the
moisture which caused the problem in the first place.
Step 2 is to
replace any damaged wood that has become structurally
weakened. A qualified carpenter may be needed to
perform these repairs. Step
3 is to treat new and existing wood with a
borate wood preservative to prevent growth of the dry
rot fungus and kill any fungus already in the wood.
Borate
is available as a dry powder or a glycol-based
liquid concentrate. The powder form is generally
less expensive but there's some evidence that glycol
improves the absorption of borate into the wood
fibers. One popular liquid borate product that is
specifically made to protect wood from dry rot is
called Bora Care (see Using
Bora Care To Protect Wood From Dry Rot) and
one of the powder forms is called TimBor
(see Using TimBor to Treat
Wood Against Dry Rot).
After
mixing with water either product can applied to dry,
unfinished wood with a garden sprayer or paint
roller. Some applications require two coats (see
label instructions) and a colored dye such as Turf
Mark (tm) is useful to mark treated areas. Neither
TimBor nor Bora Care are generally available in
stores but can be purchased here
(DoMyOwnPestControl.com).
Related
Articles
Which
Insects Damage Wood?
Using
Boric Acid Wood Preservatives
|
|
|
'Bugs Needs Your Support!
If our information is useful
help us
maintain and grow 'Bugs. Visit our Support
Page or shop at
Amazon, one of our favorite affiliates. Amazon
is not just books and Kindles, they even have bug
stuff!
|
|
|
Don't forget to bookmark
us for next time - press ctrl-D in most browsers.
|
|
|
|
Mission:
To provide accurate, up-to-date and unbiased
information for solving common insect and mite
problems around your home, business and landscape
using least-toxic methods.
Jack
DeAngelis, PhD,
, email:
[email protected]
Please
see the Disclaimer
statements as well.
|
|
|
|
Copyright © 2004-...
LivingWithBugs, LLC. All rights reserved.
|