How to Keep Kiln Dried Lumber From Warping
Introduction:
Kiln-dried lumber is simply wood placed in an industrial kiln, then allowed to dry naturally. Kilns are large ovens that use varying degrees of heat and humidity to control the rate at which water leaves the wood. Storing wood indoors without air movement will cause moisture levels to rise due to a lack of proper ventilation.
The most significant advantage of buying kiln-dried lumber is that it’s less likely to warp or crack than traditional green (freshly cut) lumber. In this article, I will discuss ‘How to Keep Kiln Dried Lumber From Warping.’ So let us get started.
Why Does This Happen?
When certain species of trees are freshly cut (or ‘green’), they contain high amounts of bound water within the tree’s cells. This bound water often turns into free water as part of a drying process known as seasoning.
As free water evaporates away from the cells of kiln-dried lumber, the bound water within the cell walls is forced out and ultimately replaced with air which causes the wood to become lighter. The more free water that’s present and the faster it evaporates (or ‘dries’), the less time there is for micro-fissures to start forming.
These micro-fissures are often filled with air as part of a natural process known as ‘compression seasoning,’ whereas exterior moisture is drawn back into the cells by water tension. Compression seasoning ultimately reduces weight but causes splitting along annual growth rings as shrinkage occurs unevenly throughout an object due to differing densities and species types.
This weight loss is average, but sometimes it can be amplified. For example, certain wood species may contain more free water than others, and the amount of bound water within the cell walls may not be uniform throughout an object because of different densities or types.
The result will often create warping, which usually occurs at points where high amounts of tension are being exerted on a board; such as in wide boards during seasonal changes in humidity levels, along with cut ends when planing, and especially when stacking lumber in rows with alternating end grains against each other.
A Detailed Stepwsie Guide on How to Keep Kiln Dried Lumber From Warping:
Kiln-dried lumber will warp if it is not stored correctly or if humidity levels are too high.
Step 1- Buy Warping-free Kiln-dried Lumber.
If you are buying wood for a project, make sure the price includes the cost of warped pieces being replaced with new ones before beginning construction. Also, ask about quality certs and warranties on your purchase to ensure that they stand behind their product. If your vendor cannot guarantee their milling practices, find another supplier for your project material needs.
Warped boards can be hard to detect visually in most cases, so be sure to inspect all deliveries before signing the receipt book at the receiving end.
Step 2- Keep Humidity in Your Home Below 45% to Prevent Warping in Kiln-dried Lumber.
Since moisture is the leading cause of warping, keeping the humidity level in your home below 45% will prevent it from happening.
There are several methods for doing this, depending on where you live and how high your humidity levels are. Here are some tips:
-Keep doors open when people go outside so that air can circulate freely through the house
-Use dehumidifiers or air conditioners during humid months to keep indoor conditions dryer than outdoor weather -Install an exhaust fan over stove vents to remove moisture that accumulates while cooking -Install a whole-house ventilation system if you notice cracks beginning to form in your walls or foundation
-Run a water softener if you have hard water, so minerals don’t leach into the cabinetry and cause warping
-Maintain well-insulated homes to avoid moisture accumulating in poorly ventilated areas
Step 3- Keep Humidity Levels Below 50% When Kiln-dried Lumber Has Just Been Delivered to Reduce Warp Potential.
Humid conditions often cause warping, but keeping humidity levels below 50% will also help prevent it. If you are expecting an outside shipment of wood products, keep doors closed for a few hours after delivery until air circulation can dry out the area surrounding the new material.
It may be advisable to install a small dehumidifier in the room where noticeable moisture is present after delivery to ensure that conditions do not allow mold or mildew formation.
Step 4- Turn Kiln-dried Lumber Every Two Weeks to Keep the Board Face Looking Great
Warping will often begin occurring on edged and ends of boards, so check them regularly for signs of distortion.
Hold the board at one end between your thumb and forefinger with your other hand placed flat on top of it to correct the problem. Then twist your hands in opposite directions to bend the warped board back into proper alignment.
Repeat this process with all affected pieces until they are stabilized. Remember to turn each piece over after removing it from its place (i.e., rotate a horizontal bit 180 degrees). Doing this will help prevent the appearance of cupping.
Step 5- Stabilize Warped Boards With Clamps if Twisting Them Back Into Shape Does Not Work.
If you cannot stabilize a board that is warping, it may be necessary to clamp both ends of the board firmly until it stays in place. Be sure to use wood glue on all joints for this application, as screws will not hold well enough.
For long pieces, cut small wedges out of scrap lumber and screw them through the baseboard at both ends, so they stick up vertically between the clamps holding your project together. This will keep your board from slipping while being glued and before final installation.
Step 6- Keep Humidity Levels Below 40% When Kiln-dried Lumber Has Just Been Glued Together to Reduce Warp Potential
For added protection against warping, keep humidity levels below 40% for a few days after gluing boards together. This should be sufficient time to allow the glue itself to dry and help prevent any moisture-related problems from occurring.
Step 7- Install Kiln-dried Lumber With Stainless Steel Screws Instead of Galvanized Nails or Staples.
Galvanized nails are not designed for high humidity conditions, so they may rust if used in an area with moisture present.
Stainless steel screws will hold up much better when appropriately installed into wall studs or ceiling joists that have been prepped with wood glue before being driven into place.
Conclusion:
I hope this article has effectively learned “How to Keep Kiln Dried Lumber From Warping.” Ensure all the precautions while performing the process. Thank you and have a nice day!
You may Read also: How to Store Pressure Treated Wood
