Long-length, vacuum-dried timbers from
Hearthstone
Until now, there has been no commercially practical way to dry huge logs and
timbers. An ordinary heat kiln will only dry wood to about 5/8" on the surface. That is like using a BB gun to sink a battleship.
Now, after years of investigation and research, Hearthstone has a
multi-patented process that allows us to dry large timbers in volume, at high
quality, and a reasonable price.
The key technological advance is the process of drying the timbers in a large
vacuum chamber. This allows us to solve several problems and introduce new
benefits that were not practical before:
Drying in a vacuum makes all the difference. In a vacuum,
moisture exits the log at a lower temperature and at a faster rate than in a
conventional kiln. This allows us to get the moisture content in our huge
logs and timbers down to a meaningful moisture content - consistent
throughout the timbers - at a reasonable cost and amount of time. The
entire process is completely tailored to both performance and efficiency.
Click photo of kiln to enlarge.
The moisture content throughout the logs and timbers can be reduced
to a meaningful level. Previously, the term “kiln dried” logs
didn’t mean much, because it was far too costly – in time and money – to
dry large timbers to an internal moisture content low enough to
improve the value and utility of the timbers.
The vacuum chamber is large – and is designed to dry large timbers.
Previously, kilns were designed for drying boards – not logs and timbers. They
were suitable only for short, small diameter logs and timbers, and even then the
results were not acceptable. Timbers up to 40’ in length will fit
in our kiln.
The drying process within the chamber itself is highly complex, automated,
and computerized. This solves the problem of uneven drying when trying
to dry logs and timbers in older, conventional kilns. The new process
lowers drying times and reduces defects.
The time in the kiln is dramatically shortened. Previously, kiln
time was 3 or more times as long. This was especially true for large
timbers – and even then, less than acceptable results had to be tolerated.
The old trade-offs...
Until now, the only choices for log and timber frame lovers were:
- A customer had to use the huge logs and timbers (that made them love log
and timber frames in first place), and then accept specialized construction
techniques and movement of large green timbers. Hearthstone built
thousands of homes like this. If Hearthstone, the builder, and the
customer all worked together following our systems, it was certainly
possible to build a beautiful and functional home. But, of course, it
was an involved process requiring attention to many details and inevitable
compromises.
- Or, a customer had to use short, small diameter logs that could be “kiln
dried”. This “solution” wasn’t ever acceptable to Hearthstone.
First of all, the use of short, thin logs was contrary to what we were about
and what our clients wanted. Secondly, we found that logs or timbers
advertised as “kiln dried” didn’t really mean much. Companies
were vague about specify key issues such as internal moisture content, how
the moisture content was calculated, the evenness of drying, and the amount
of tolerance in specifications. Those logs were merely surface-dried,
with very little ultimate benefit.
As always, Hearthstone is your leader in innovation, quality, and commitment
to the customer.
We never quit searching for popular, practical, affordable product design and
technology improvements.
Drying these timbers will nearly eliminate shrinkage (no system could totally
guarantee 100% stability in any building material) in large timbers and logs.
This was previously not possible in any commercially feasible way. It will
also dramatically reduce log and timber movement, which - of course – will
help stabilize walls and joinery. Keeping joints the way they were when
they were so carefully cut is a particularly satisfying development for our
craftsmen.
Our approach is to dry to near the “equilibrium” moisture content, which
will minimize shrinkage and settling as much as possible. When you buy
vacuum-dried timbers from Hearthstone, you will invest in clearly understandable
specifications such as moisture content throughout the logs and timbers. If you do not see the HeartDried grade stamp, that means the wood is "green". Ask to see a kiln-dried grade stamp!
With this technical breakthrough, you have yet another reason to visit Hearthstone
and proceed with your home and lifestyle vision. And, you can take pride
and confidence that your home came from Hearthstone: the product, design, and
engineering leader in log and timberframe homes and commercial structures for over 43 years. For more information call us at
(877) 662-6135.
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