Mortar (Cement) Chinking vs Synthetic Chinking

Posted by Terry Jennings on

Mortar (Cement) Chink vs Synthetic Chinking. 

Up until the early 1980’s many log cabins had mortar chinking installed. Today, the majority of chink used is made of a synthetic mixture. While, mortar chink is not as common any more and comes with a few problems, there are still some use cases for it.

What is mortar chink?

Before we get started many might be wondering, what is mortar chinking? Mortar chinking was very popular between the 1950’s through the 1980’s and has been replaced with synthetic chink for many reasons. Mortar chinking also called cement chink is a chink made from a mixture of clay, lime, silt, sand, ash, cement, dirt, and other materials. Another term for this type of chink is “Portland cement” and there are many different recipes to make it.

What are the disadvantages of mortar (cement) chink?

Mortar chink was popular mostly because synthetic chinking had not yet been created. The main disadvantages of mortar or cement chinking are that it does not seal properly between the logs and often holds moisture against the logs adding to rot. One problem with mortar chink is that it does not last as long and is known to chip. It is also very difficult to repair, remove, and replace. Because of these reason most people have switched to synthetic chinking. Mortar chinking is also much more expensive in the long run due to the damage it can cause.

When to use mortar chinking?

Most professionals do not recommend using mortar chinking as the advantages to synthetic chinking are far too great. However, mortar (cement) chinking is most used by hobbyist and those who are building a homemade cabin. Mortar chinking should only be used when logs have been felled and dried locally. This means the logs will not flex as much as they are in their original climate. Mortar is also much cheaper and perfect for sport or small hunting cabins. If you are looking to used mortar chinking then here are a few recipes:

Homemade (mortar) chinking recipes.

If you have decided that mortar chinking is right for you, then you might be looking for good homemade chinking recipes. After asking our community here are the top mixtures that people use. The goal is to have a creamy peanut butter mix and to stay consistent. Remember that you want the log to be able to breath. If you have or know of a great recipe leave it in the comments below.

Cement and Sand

1 Part Pre-Dyed Cement

1 Part Fine Sand

Clay, Sand, and LIme

1 Part Clay

1 Part Coarse Sand

1 Part Lime

Clay, Ash, and Salt

4 Part Clay

2 Part Wood Ashes

1 Part Salt

Cement, Sand, and Lime

6 Part Sand

2 Part Portland Cement

1 Part Lime

A good trick is to make one bucket and then pour half into another bucket. Then fill both buckets. This method helps to keep consistency. Never change your mixture once you start; by changing the mixture you will risk failed chinking and it chipping away from itself.

What is synthetic chinking?

If you have a cabin and you don’t want to risk the damage that can occur with mortar chinking, then you most likely will want to use a new synthetic chinking. Synthetic chinking is a water-based elastomeric material that is designed to look like traditional mortar chinking. Synthetic chinking is much more flexible and easier to apply, once dried it still maintains an elastic feel to it.

What are the disadvantages of synthetic chinking?

There are not many disadvantages to synthetic chinking. The only disadvantage is that the short term cost is higher, but it will save you money in the long-run. Synthetic chinking is all around better than mortar and the only real disadvantages are mostly preference and price.

When to use synthetic chinking?

If you are serious about your cabin’s health then you will want to use synthetic chinking. Synthetic chinking should be used on the majority of cabins as it is much better at protecting logs than traditional mortar is. Unless you are building a homemade cabin where you want to build everything traditional, then you will want to use synthetic chinking. So what are the benefits to using synthetic chinking and why is it better? There are many benefits including a huge cost savings, here are a few more.

The benefits of synthetic chinking are:

  • It seals to the log much more efficiently preventing rot.
  • It is less likely to crack (check.)
  • It flexes with the logs and allows you to use logs from other locations.
  • It comes in a variety of colors.
  • It last much longer than traditional chinking.
  • It is easier to repair.

  • Recommended chinking brands.

    As a log cabin company we have worked with many contractors. The two brands that we have heard the most praise for are Log Jam and Perma Chinking. These recommendations come from many years as a log cabin company and from the experience of our vast list of contractors.

    Log Jam Chinking Overview

    Log Jam is a synthetic chinking that handles joint movement up to 100% on joints up to 4” while still maintaining its original appearance. Log Jam is also the only chinking to hold a UL one-hour fire rating. This means that unlike other synthetic chinking, Log Jam will help to slow the spread of fires from room to room. Log Jam is an excellent choice for a new log cabin. You can read more about log jam here.


    Perma-Chink Chinking Overview

    Perma-Chink is one of the easiest chinking to apply to your home. Perma-chink is great as you can use it for both interior and exterior sealing. It is also a very low VOC (Volatile Organic Compound) formula; meaning that is safer to work with and will have less fumes. It also comes with a 10 year warranty. To learn more about Perma-Chink click here.

    Mortar chinking or synthetic chinking?

    There is no right answer, only preference. Mortar chinking is traditional and great for those who have a hobby project or those looking to have a completely traditional log cabin. In most cases you will want to use synthetic chinking to ensure that your log home lasts. If you have questions about chinking feel free to reach out to us or let us know about your chinking experience in the comments below!


    • I purchased an older cabin and the logs at the snow line have not been taken of and show signs of distress. Can I put a smooth coat of log jam across them, similar to how someone does drywall? Than apply stain over it to match the color of cabin?


      James on

    • Thank you for your inquiry. The Perma Chink is soft but still elastic to move with the logs. It will take about 2-3 weeks to fully cure but still stay pliable. It is also stainable and paintable.



      I-Wood-Care Sherburne, NY 1-800-721-7715 on

    • When fully cured is perma chink hard? Or is it a bit soft? I started chinking a week ago and it still feels a bit soft or pliable to the touch / is that how it feels when cured fully too?

      Charlie on

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