Marks Lumber's Process for Drying and Grading Lumber

Aug 16, 17

Drying Montana Lumber 

After the cutting process, lumber products are ready to be dried and the yard/planer team at Marks Lumber takes over. This is another environmental differentiator for Marks Lumber. Instead of packaging and shipping material to another yard for continued processing or to a wholesaler, Marks Lumber continues the manufacturing process with the end result being products going directly to customers or into inventory. Physically, units are moved just a couple hundred yards up the hill to the staging area where they will be moved into the kiln for drying. 

Periodically, the moisture of the lumber in the kiln is checked to determine how long the ‘charge’ needs to stay in the kiln.  Generally, 1-inch material is going to require about a week to dry.  Once a moisture content of 8-12 percent for 1-inch material is reached, the kiln is emptied and material is moved to a dry shed where it is stored until it is graded. 

The kiln at Marks Lumber is powered by bio-fuel – ‘waste’ material that will not make lumber or landscape products. This waste material would have eventually decomposed and released carbon, but by using it as bio-fuel we can minimize the energy used and carbon released. 

The Importance of Drying Lumber 

This might seem elementary, but drying lumber is a critical step in any lumber manufacturing process. After live trees are cut, they begin to dry immediately. Inland Douglas Fir is usually about 35% moisture when it is cut. As wood dries it shrinks, checks (cracks) and moves. Obviously, these changes can wreak havoc on a structure. In the careful drying of lumber, we maximize the quality of wood we produce by working around the shrinkage; checking movement that occurs when it dries before we continue to manufacture or build anything from it. 

Fun Fact: Wood only shrinks across the grain and tangent to the grain. Not with the grain! So a 16 ft-2 in long board stays 16 ft-2 in as it dries. This is a very unique characteristic of wood that we often overlook, and is what makes it such a flexible and valuable building material! 

Grading Montana Lumber 

Grading lumber is a time-consuming and, therefore, expensive process. At Marks Lumber, an experienced grader calls grade for every board we produce. The rest of the grading team is then responsible for pulling those boards as they move down the chain and putting them into the appropriate lumber piles. Graders call the best blanks “rough” - short hand for “rough top” which is Marks Lumber terminology for the finest circle-sawn boards, having both the best appearance as well as the best stability.  

After they are graded boards are moved into retail, ready for immediate sale; or, in the case of blanks, warehoused until they are planed into flooring, siding, or other products. 

The care taken in drying and then grading lumber is key to the consistent, high quality lumber products that we are proud to manufacture for our customers! 

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