Chinking Your Log Home

Chinking, Caulking and Sealants (terms that are often used interchangeably) can be used to seal gaps in the logs or between the logs. These can range from:

  • Caulk: A smooth colored sealant with great adhesion and stretchability.
  • Textured Caulk: A smooth colored sealant with a bit of texture e.g. sand, are added to give an appearance that along with the color choices tends to blend in with the look of the logs. Used in gaps up to 1″ to fill checks (cracks) in logs or when the chinking gap is less than 1″ wide and you want a matching color to that of the logs and log finish.
  • Chinking: is the most textured mortar-like material seen between courses of logs in many log homes. Often used in a contrasting color to that of the logs and can be used (with care) in gaps up to 5″  wide.

Modern Chinking is a flexible 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 it does and what it is 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 (or chinked) 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 usually held together by the notches (usually round or dovetailed notches).

When a ‘chink style’ log shell is erected at your site there will often be a backer rod (or equivalent) pushed between the courses of logs (one strip to the inside face of the logs another to the outside face) and then a chinking compound is applied on the interior and exterior using the ‘backer rod’ as a base to apply the chinking against.

What does chinking do?

Quite simply chinking stops air, insect and moisture infiltration into your home. With the backer rod it helps insulate your home as well. Chinking can also be a design feature of your home often contrasting with the color of the logs.


Chinking Coverage Estimator
Lineal Feet per full gallon

Width of Joint
Average Depth .5″ 1″ 1.5″ 2″ 2.5″ 3″ 3.5″ 4″
1/4″ 154 77 51 39 31 25 22 19
3/8″ 102 51 34 25 20 17 14 13
1/2″ 77 39 25 19 15 13 11 9

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.
(all caulks/textured caulks/chinking use the same quantity of space, regardless of brand).

What is chinking made of?

Traditionally chinking was a mixture of clay, lime and sand with variations based on what was locally available. Nowdays, it’s usually 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. (This is due to it’s being non-elastic).

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 have “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 Methods

Chinking can be applied in a variety of ways listed here from lowest to highest tech:

  • Scoop some chinking from the bucket into a small container and use a metal or plastic spatula to apply
  • Scoop chinking into a grout bag/cake decorating bag with a nozzle at the end and squeeze the bag to apply
  • Use a caulking/chinking gun and apply tubes of product. These are available in the 10.5 oz/ and quart size (fits the 29 and 30 oz. sizes also) these “guns” cost in the $3 to $60 range depending on quality.
  • 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 dispensing nozzle 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. (There are variations on this involving “follow plates” and special “loaders” to ease the effort expended in loading the “gun” and to reduce the mess). Some contractors use these methods to great success without purchasing or renting an expensive chinking machine.
  • Use a chink pump that sucks the chinking from the bucket (or the bucket of chinking is dumped into the “hopper” of the machine) and sends it through a hose to apply. This is a large professional quality machine that many chinking contractors use. Running several thousand dollars CONTACT US if you would like a quote.

No method is intrinsically better than the others – it depends on the effort you want to put into the project the time and money you have and how you or your contractor prefer to work.

The method most of our customers (homeowners and contractors) use is the manual bulk loading gun for small to mid 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.

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.

Some people start their chinking project by purchasing 25-50 of the inexpensive foam brushes in a size slightly smaller than your anticipated chinking width. They then put all brushes in a bucket of clean water with a 2nd bucket with water nearby…When ‘brushing out’ the bead of chinking/caulking they will grab a brush out of the water give one good shake to get rid of the majority of water then brush over the chinking once turn the brush over (gives you a clean side) and use once again…then into the 2nd bucket where all the used brushes go…till you run out. Rinse the brushes and repeat. The key to to use each clean brush only once per side…that will keep the ‘edges’ clean.

Keep your tools moist with a misting of water (some prefer to use isopropyl alcohol or a 50/50 combination of water/isopropol 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. Remember to cleanup before the chinking sets up.

Suggested application guidelines using bulk loading guns and foam brushes.

Gather all the materials you’re going to need.

  • Backer Rod
  • Chinking or Caulking
  • Caulking Gun(s) and Followplate-(remember different type plates for different brands of chinking)
  • misting bottle
  • foam brushes
  • 2 empty buckets for storing and cleaning brushes
  • spatula or putty knife
  • ladders scaffold. depending on your project
  • To start you can either apply backer rod to a section of wall that you feel you can chink in a couple of days or with a large enough crew you can go ahead and apply backer rod to the entire building.
  • Next prepare tools if everything is new spray the inside of the barrel of the gun with a silicone type spray to lubricate the walls of the barrel of the gun and make it easier to pull the the activator rod (which in turn sucks the chinking caulking into the gun (dispenser).


Chinking needs to be applied about 1/4 to 1/2 inch thick.

  • PermaChink recommends 1/2″ at the “thin” spot
  • Sashco states 3/8 at the thin spot keeping the thickest areas under 1/2″ when possible.
  • 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 develope as the logs dry and move seasonally.

Too thick and the chinking (and your money) is wasted and will take too long to cure. Additionally too thick and the chinking may not set up properly. This is particularly true in colder weather. The chinking may go through several freeze/thaw cycles before setting up properly. Eventually the water part of the chinking evaporates and the latex part of the chinking didn’t set up as intended. This may lead to a slumping or possibly “spongy” feeling to the chinking. Basically don’t put it on too thick and watch the temperature when applying and during the curing process.

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 on line at the respective products and in our catalog.