Virginia Urban Wood Group
News & Updates
April 29, 2021 | Issue-7
Happy Arbor Day 2021!

Welcome to the seventh edition of the Virginia Urban Wood Group's newsletter! Our planned schedule is to offer this newsletter every other month.

Arbor Day is Friday April 30th. While this is a day dedicated to tree planting, it is also a reminder that the management of the urban forest continues beyond the end of the biological life of the tree. Urban wood is part of the "full circle management" of our urban forest resources.

We hope that you find this newsletter useful and enjoyable!

Joe Lehnen
VA Dept of Forestry
Urban Wood Program Coordinator
The Art and Science of Drying Wood
Providing humbling moments we
have all experienced...
Drying Kiln Types

In this issue we explore three types of wood drying kilns: Dehumidification, Vacuum and Solar. Each of these kilns have advantages and disadvantages regarding the initial cost, operational expenses and drying time. Here are the basic differences among the three kilns:

Dehumidification: The dehumidification kiln uses a heat pump system to remove the water from lumber. One primary advantage of this type of system is that it recycles heat continuously instead of venting away heated air, as a conventional kiln does. The air in a dehumidification kiln circulates around the wood at a temperature of 95-100F degrees. Even though are operated by electricity they are still more economical to operate than a traditional gas-fired kiln.

Vacuum: The vacuum kiln utilizes a vacuum to lower the temperature at which water boils (evaporates). Wood is stronger at a lower temperature. By drying at a low temperature we can accelerate the drying time without harming wood. Vacuum pressure also sucks the water from the core to the shell, which is particularly handy for thicker dimensions.

Solar: The solar kiln dries wood exactly as you might think, the power of the sun! The size of the collector keeps the kiln from overheating, which causes the wood to check and split. The kiln is simple to construct and utilizes a passive solar collector, four insulated walls, and an insulated floor. The roof is made of clear, greenhouse-rated, corrugated polycarbonate. Most solar kilns are built by the wood producer and are not overly expensive to construct.
Photos by: Dylan Greenquist
Wood Products

"There's sawdust on my floor" - those are the five most feared words that wood producers can receive from a customer. The goal of everyone in this business is to make sure that never happens.

All manufacturers of wood products, whether they originate from fresh-cut or reclaimed urban wood, want to produce a pest free product. Wood boring insects can be found in wood and wood products, some of which are invasive plant pests. They can cause damage on the product and, if allowed to escape into new environments, they can negatively impact native tree species. One of the best methods to prevent this from happening is to kiln dry wood, even reclaimed urban boards, to an internal temperature of 140 degrees Fahrenheit for a period of three days.
Invasive species, such as the spotted lanternfly, Asian longhorned beetle, emerald ash borer, gypsy moth, imported fire ant, boxwood blight and giant hogweed, wreak havoc on the environment, displace or destroy native plants and insects, severely damage crops and potentially cause the closure of foreign markets to those U.S. products that originated in infested areas.
The Virginia Department of Agriculture and Consumer Services (VDACS) works to protect the state’s environment, as well as agricultural and horticultural interests, from pests and diseases. VDACS can help with the movement of wood products to include inspection and certification, compliance agreements, clarifying federal and state quarantines and providing information on approved mitigation measures.
 If you need help understanding these regulations, please contact Tina MacIntyre, VDACS, Office of Plant Industry Services, at (804) 786-3515 or

Nyle Dehumidification Kiln
Po' Critter Farm & Lumber
Barboursville, VA
Larry and Alyson Sappington share their words of wisdom for drying lumber in a dehumidification kiln:
- Be sure to sticker the lumber properly. This is a step that's very easy to shortcut by not using an adequate number of stickers, not placing stickers at the very ends of the boards, not providing a solid and providing a level base for the lumber stacks. We have learned that the quickest path to degrading lumber is improper stickering, during both the air drying process and the kiln drying process. 
- Determine the maximum moisture content of your lumber that you are comfortable with before placing it into the kiln. This will vary with different kiln operations and technologies. We prefer to air dry our lumber down to a maximum of 25% before placing it into the kiln. In our experience, this seems to minimize lumber degrade during the kiln drying process. 
- Monitor your kiln more than once per day. We've learned that the lumber drying process is part science/technology & part nuance. Every batch of lumber is different and even every board is different. Therefore, we visit our kiln twice per day, checking moisture content, dry bulb/wet bulb temps, condition of lumber, placement and effectiveness of baffles, and even the smell of the lumber as it's drying. 

For more information about Larry & Alyson's business and the products they manufacture, please visit their Facebook page >>

 iDry Vacuum Kiln
Genuine Timbercraft
Montpelier, VA

Dylan Greenquist of Genuine Timbercraft shares his words of wisdom for drying lumber in a vacuum kiln:
1.   When drying wood with a moisture content over 25%, start with lower temp and use low power mode. Slowly ease temperature up until you reach 160 degrees.
2.   You will often need to dry longer than one week per inch of thickness. Check the moisture content each week.
3.   The kiln comes preset to discharge water every 24 hours by releasing the vacuum and opening the drain. I like to set it to 48 hours when drying walnut to keep more moisture in the chamber. This practice prevents the outer shell of the wood from becoming too dry thus trapping moisture in the center of the material.
 Always begin with air drying the lumber. I have found that the longer you air dry, the better. If you are cutting material 8/4 or more, you will need to air dry at LEAST 6 months. Summertime air drying really benefits the quality of the material. It also results in less time in the kiln. I would not suggest kiln drying oak green. I have never had good luck doing this. Some of my material still air dries for 1-2 years before going into the iDry vacuum kiln.

For more information about Genuine Timbercraft, visit their webpage >>

Small-scale dehumidification kilns can be constructed as a DIY project based on the U.S. Forest Service design plan. These plans are both straight-forward and cost effective. Here's a link >>

Solar Kilns
Rocktown Urban Wood
Harrisonburg, VA

Rocktown Urban Wood built their first solar kiln in 2019 to dry lumber for their new urban wood business. The demand for Rocktown products increased exponentially and they soon realized that a second kiln was needed! Business continues to be pretty solid and both kilns are always filled to capacity. The Rocktown crew shares words of wisdom for drying lumber in a solar kiln:

First Tip: Be patient. Very Patient. Solar Kiln Drying has been a slow process for us and we are constantly thinking of ways to speed things up. Most charges extend beyond our preconceived expectations of duration. We are tempted to pull charges out early to get other charges started. Let the charges run their full cycle and remember after the initial build costs the rest of the process essentially comes free.

Second Tip: Weigh down kiln charges. Around a year ago we started putting granite slabs on the top of our charges and we have noticed a significant improvement in the condition of the lumber at the end of the process. The weight does take up space in the kiln that could otherwise be used to dry more lumber but the benefits to the dried material far outweigh the offset of the size of the charge.

Third Tip: The baffle is integral to the production level of the kiln. We use black rubber (EPDM) roofing sheets for our baffle. It uses three different panels. One is solid from end to end and is suspended from the ceiling directly to the fan mounts. The other two are partial sheets that have been sliced like walk-in freezer doors. This allows for the sides of the baffles to extend to the floor of the kiln as well as contour to different size and shaped charges. The tight floor to ceiling and wall to wall baffle system optimizes the airflow through the charge and puts the air movement where you want it.

Also, we air dry our green lumber in a shed for an average of 4-6 months before placing the boards in the kilns.

Additional information about Rocktown Urban Wood can be found at their website >>

Both of these solar kilns are based on the Virginia Tech Solar Kiln design plan. These plans are both straight-forward and cost effective. Here's a link >>

Asian Longhorn Beetle (adult)
Photo Credit: Dr. David Coyle, Clemson Univ.
Powder Post Beetle Damage
Photo credit: NC State Extension Service


Many thanks to Trees Virginia (Virginia's Urban Forest Council) for hosting this newsletter and allowing access to their Constant Contact platform!
The Virginia Urban Wood Program is supported by the Virginia Department of Forestry and a grant from the U.S. Forest Service, Southern Region.
The Marketing Corner

Count to 10....

Doesn't take too long does it?! So what is the point of this quick exercise? Ten seconds is the the average amount of time spent by people looking at a post on social media platforms like Instagram or Twitter.

Think about that for a moment - you can expect about ten seconds of a person's attention dedicated to whatever you post, be it a picture or text. In that small tidbit of time you have to make sure they notice your post, understand your message and hopefully entice them into further engagement by seeking more information about your products or business!

Do not let this 10-second rule discourage you. While people may spend only ten seconds looking at your post, on average people spend 126 minutes, or two hours and six minutes, on social media every day!

Keep posting, it is well worth your time and will be very beneficial to your business!