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Wood
is the most versatile
building material in the world. Pound for pound, it is
stronger than steel or concrete. Wood is easy to work, beautiful, functional
and durable. However, it has a couple of Achilles heels. Because it is
an organic material (one that was once alive) it is subject to natural
decomposition. Once a tree is cut down, its life support systems are cut
off and it's Mother Nature's job to return it to the earth.
The biggest enemy of wood is water.
Water is the most important life sustaining substance on earth. Without
it nothing can survive. While a living tree must have water to survive,
it can destroy lumber, timbers, posts and beams. Insects (like beetles,
carpenter ants and termites) are more likely to attack damp wood than
dry wood. Decay organisms (AKA wood rot) needs moist wood to survive.
If you can keep wood totally dry, it can last indefinitely. So the best
wood preservative in the world is dry air…and it free! However, when the
moisture content in wood is above 28% it can become compost in less than
5 years.
A living tree
has a very efficient water transportation system to take water
and nutrients from the roots up to the branches and leaves and chemicals
produced in photosynthesis from the leaves down to the roots. Under a
microscope wood looks like a bunch of straws arranged side by side, end
to end, much like a load of PVC pipe on a flatbed truck. This pathway
still exists after the tree is cut down and can still transport water.
Therefore, ends of boards, timbers and posts will wick water very efficiently
much like food coloring in a celery stalk. By the same token, when wood
dries, most of the moisture leaves through the end grain.
Keeping
wood dry becomes
the challenge and in the real world, it's seldom possible to isolate wood
from moisture. Pressure treated wood should always be used when you know
the wood will get wet or when the wood will be in contact with concrete
or dirt. However, pressure treated wood has only been readily available
for the last twenty-five years or so and so there are thousands of residential
and commercial structures that have untreated wood in areas exposed to
the elements.
Detecting
Rot
Wood Fungi can do as
much damage to a house as termites but it's much harder to detect. Tell
tale visual signs are blistering and peeling paint, areas of discoloration,
groups of small cracks across the grain lines and in worst cases, mushrooms
growing out of the wood. Other times wood decay is less obvious. Rotten
and rotting wood is usually softer than solid wood and offers little resistance
when probed with a knife blade or ice pick. Rotten or rotting wood also
sounds different with tapped with a hammer. Solid wood has a resonate tone,
rotten wood is more of a dull thud. The decay process causes a loss of strength
and weight in wood. As a matter of fact a 1% weight loss due to brown rot
or dry rot can weaken the wood member by 50% as documented by the Forest
Products Laboratory in Madison, Wisconsin. Decay organisms need four things
to survive:
- Oxygen - logs submerged in
water don't rot because there is no oxygen.
- Water
- Dry wood, like cabinets and furniture don't rot because there is no water.
- Food - Pressure treated wood does
not rot because the food supply (the wood) has been poisoned.
- Temperature - between about 40 and
95 degrees. There are wood buildings in Siberia that are over 600 years
old. Its too cold there for wood destroying organisms to get established.
Take away any one of these four elements
and rot will not survive. When all four conditions exist, rot can and often
does take place and can destroy wood members in less than 5 years. Also,
rotting wood is very attractive to a host of insects including carpenter
ants, termites and beetles. When wood is damaged due to decay or insects,
you have to take a pro-active approach to the cure. A combination of direct
and indirect tactics is the best solution.
Indirect
tactics include but are not limited to the following: Redirect
the water away from the wood. This can be done with flashing, paint, gutters,
and downspouts or vapor barriers. Wood decay needs at least 15% moisture
content to sustain itself and insects are more attracted to damp wood than
dry wood. Wood should never be in contact with the ground or concrete unless
it is pressure treated.
Direct tactics mean treating the wood
itself. Borates are the most effective way to treat wood in place. They
are odorless, colorless and highly effective against all known wood destroying
organisms, yet no more toxic to humans than ordinary table salt. Borates
have a long track record of use in Europe and New Zealand, but have been
somewhat limited in the US, mainly due to unavailability outside of the
Pest Control and Utility pole maintenance industries. Now, through Wood
Care Systems, they are available to everyone.
There are Four types of borate based wood preservatives:
- IMPEL
Rods are solid glass-like rods that are 100% active borates.
They are inserted into drilled holes and dissolve with the available moisture.
This moisture becomes the carrier and the borate preservative will diffuse
several inches from its origin.
- Bora-Care is a thick liquid that is
40% active borates. It is mixed with equal volumes of water and is brushed,
sprayed or injected into the wood. It has the ability to diffuse through
wood as dry as 10%. Bora-Care is repellent to termites as well as making
the wood toxic to them.
- BOARD DEFENSE® or Tim-bor is a
powder that mixes with water at a rate of 1 pound per gallon. It is 100%
active borates as a powder, but once mixed is a 10% solution. It is applied
in two coats to wood with a moisture content higher than 25%.
- Jecta is a paste packaged in a "syringe".
It is 40% active borates and is used to inject cracks, crevices, checks
and holes. As a rule Jecta is used when the wood is too small for an IMPEL
Rod. Also, Jecta is used sometimes to inject into the hole before you insert
an IMPEL Rod. Borates use the water that is present in rotten or rotting
wood as the carrier to disperse them throughout the wood. In other words,
water becomes the Trojan Horse that carries the poison pill. The borates
can be used individually or in combination with each other. The best treatment
for active decay or insects is a combination of Bora-Care and IMPEL Rods
to arrest the decay and keep it from returning, then epoxy restoration products
for the repair. We call this the Total Wood Restoration System.
The Total Wood Restoration System is outlined as follows:
- Remove
the decayed wood. Then, using the chart for IMPEL Rods, determine the proper
IMPEL Rods size and spacing.
- Drill
holes for the IMPEL Rods.
- Fill each hole with BOARD DEFENSE®
, then apply BOARD DEFENSE® by spray, brush or roller to the outside
of the entire wood surface. Also apply it to the cavity where the rot was.
- Allow several hours for the BOARD DEFENSE®
to absorb into the surrounding wood.
- Insert the IMPEL Rods into the hole
once the liquid is absorbed.
- Plug each hole with epoxy or other
wood filler.If wood repair is necessary then proceed to the following steps:
- Wait a minimum of 24 hours or until
the wood surface is completely dry.
- In the area that was decayed, apply
one coat of ROTFIX consolidant to solidify punky wood.
- Then,
while the ROTFIX is still tacky, apply wood SCULPWOOD.
- Allow several hours for the TIMBR
Flex to cure. Then, sand flush and prime with TIMBR Prime. Then, paint with
100% acrylic paint to match original look This is a total system that will
provide a lifetime repair by not only stop the existing decay from spreading
and keep it from coming back, but will actually reverse the damage and add
strength back to the wood.
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