By: T. Johnston – Log Home Store, Inc.

Chinking is the gritty, mortar-like material seen between courses of logs in many log homes. Modern Chinking is a flexible, mortar-mortar textured sealant. Chinking can be a necessity or simply an esthetic addition to a log home’s appearance. Before we discuss how to chink your home, let’s cover who needs it, what does it do, and what is it made of.

Who needs it? Many of the hand-crafted log homes not built in a scribe-fit style are referred to as chinkers or chink style log homes. Several milled log manufacturers also offer log packages that require chinking. These are homes that are purposely built leaving gaps between the courses of logs. The gaps are usually created by inserting small spacer blocks that help hold the logs apart. At the corners the logs are held apart by the notches (usually round or dovetailed notches). When the log shell is erected at your site generally a backer rod (or equivalent) is pushed between the courses of logs and then a chinking compound is applied on the interior and exterior.

You may calculate gallons needed by finding the feet per gallon and dividing your lineal feet by that number.   Although this chart is rounded up where needed, it does not include waste. Keep in mind that the depth is an average depth across the joint.  If your estimations are generally short, check to see that you use average joint depth.

Chart courtesy of Sashco, manufacturers of Log Jam chinking.

What does chinking do? Quite simply, chinking stops air and moisture infiltration into your home. With the backer rod, it helps insulate your home as well.

What is chinking made of? Traditionally, chinking was a mixture of clay, lime, and sand with variations based on what was locally available. Today we use an acrylic, elastic compound that adheres to the logs and can stretch and contract as the logs settle and move seasonally. Old fashioned chinking often pulls away from logs and cracks, allowing water and insects to enter the logs.

Chinking, (or caulking), can also be used to seal any gaps between logs and notches in scribe-fit style handcrafted and milled log packages that had “gapped” for whatever reason.

Whether or not you are chinking a new or existing log home, you will need to think about the finish that is on your home or that you will be applying to make sure it will be compatible with the chinking. Both the chinking and finish you apply to your home represent an investment of time (yours or a hired contractor’s) and money (yours) and omitting this step can cost you both. Call us to verify that the combination you have chosen will work together.

Chinking can be applied in a variety of ways, listed here from lowest to highest tech:
Scoop out some chinking from the bucket into a small container and use a metal spatula to apply
Scoop out chinking into a grout bag with a nozzle at the end and squeeze the bag to apply
Use a caulking/chinking gun and apply. These are available in the 10.5 oz/ and quart size, (fits the 29 and 30 oz. sizes also), these “guns” cost in the $5 to $20 range.
Manually fill a bulk loading chinking/caulking gun from the bucket and apply. Bulk loading guns are approximately the size of the quart size guns discussed above. You unscrew the end of the gun that has the tip, dip the end of the gun into a bucket of water, (this keeps the chinking from sticking to the sides of the gun), plunge the gun tip into a 5 gallon bucket of chinking and pull up on the plunger rod at the back of the gun; in effect, sucking the chinking up into the barrel of the gun.
Use a chink pump that sucks the chinking from the bucket and sends it through a hose to apply. This is a large professional quality machine that many chinking contractors use. (We have a machine that we rent out in the NW Oregon area).
No method is intrinsically better than the others – it depends on the effort you want to put in, the time you have, and how you or your hired contractor likes to work. The method most of our customers (homeowners and contractors) use is the manual bulk loading gun for mid to large sized projects. This allows you to buy chinking in 5 gallon buckets (cheaper than buying it in tubes) and the bulk loading gun has a variety of nozzle widths available. We carry these guns for purchase or rent.

Whatever method you use, you will most likely be going back over your work with a spatula or foam brush to clean up any mistakes, to flatten the chinking out, and to make sure it is adhering to the logs properly. Keep your tools moist with a misting of water, (some prefer to use isopropyl alcohol), to prevent sticking. Since modern acrylic chinking is water based, clean up is easy if you drip any chinking on your logs. Just make sure you keep a sponge and a container of clean water nearby and correct any errors right away.

Chinking needs to be applied about 1/4 to 1/2 inch thick. (Weatherall suggests 3/16″ – 1/4″ thick across the face of the backer rod). Too thin and there is not enough to adhere properly to the logs and you may see tears or rips in the chinking, too thick and the chinking is wasted and will take too long to cure. Cleanup is with soap and water if done immediately. Protect unused containers of chinking from freezing.

If you are applying new chinking over the old mortar style chinking the process is similar. You will need to remove any loose or crumbling chinking and make sure the logs are clean. The use of duct tape (or similar “bond breaker”) over the old mortar allows the new chinking to move properly while still adhering to the log below and above.

Chinking comes in several colors and you can choose whether you want the chinking to blend in or contrast with the color of your logs. Color swatches are available. We carry Sashco Log Jam™ Chinking, Perma-Chink® Chinking, and Weatherall’s® Chinking. Check out the chinking department in our online catalog.