Wood is a living material.
Throughout the seasons, it reacts to its environment: air humidity, rain, sunlight, and temperature variations naturally cause changes in its moisture content.
Over the years, wood dries, contracts, and then expands again with the changing seasons.
This natural movement of the wood can cause longitudinal cracks to appear, particularly in solid log homes.
These cracks are not necessarily a problem. They are a natural part of the life of the wood. However, some of them deserve particular attention.
WHY SHOULD SOME CRACKS BE FILLED?
Not all cracks present a risk.
When a crack is oriented upward, it forms a cavity where rainwater can collect. If this water remains trapped inside the log, it can gradually contribute to wood deterioration and eventually lead to rot.
Cracks located on the underside of a log are generally less concerning because they are less likely to retain water.
The goal is therefore not to systematically seal every crack in the wood, but rather to protect those that are likely to retain water.
A CRACK THAT CHANGES OVER TIME
A crack in a log is not a static joint. Its width changes with the moisture content of the wood and can be significantly different between summer and winter. A product that is too rigid may therefore crack or lose adhesion as the wood continues to naturally move.
This is why Check Mate 2 was specifically designed to remain flexible and move with the crack as its dimensions change.
Its flexibility allows it to follow the movement of the wood while maintaining a watertight barrier.
HOW TO FILL A CRACK WITH CHECK MATE 2
1. Clean and dry the crack
Start by removing dust, dirt, old sealants, and anything else that could prevent proper adhesion.
The crack must then be completely dry. If water has collected inside it, it is important to allow it to dry before sealing it. A blower can be used to speed up the drying process.
This is also the right time to check the condition of the wood. If the crack reveals wood that is already deteriorated or affected by rot, this deterioration must first be treated before sealing the crack (see the article “How to Repair Rotten Wood on a Solid Log Home”).
2. Install the backer rod and masking tape
For cracks that are wide enough, generally from approximately 6 mm (1/4 inch), Check Mate 2 should be used together with a backer rod.
The backer rod helps control the depth of the sealant and maintain a consistent thickness of approximately 10 mm (3/8 inch).
The backer rod should therefore be positioned neither too deeply nor too close to the surface of the log. This thickness allows Check Mate 2 to perform properly as the crack changes over time.
Once the backer rod is correctly positioned, apply paper masking tape along both sides of the crack. This protects the wood and provides a clean, even finish when tooling the Check Mate 2.
Backer rod inserted into the crack, with paper masking tape applied on both sides
3. Apply Check Mate 2
Check Mate 2 should be applied using the 11-oz Ratchet Caulking Gun.
Apply it generously to completely fill the cavity.
4. Tool the sealant and allow it to dry
After application, tool the Check Mate 2 with a putty knife or spatula to create an even joint and ensure good contact with both sides of the crack.
The masking tape should then be removed before the product begins to dry, leaving a clean finish.
Check Mate 2 is relatively clear when it comes out of the cartridge and develops its final color as it dries. It is generally dry to the touch after approximately one hour, while full curing takes longer depending on temperature and humidity conditions.
Photo taken immediately after tooling the sealant and removing the paper masking tape
5. What happens next?
Once dry, Check Mate 2 may slightly take on the color of the Lifeline Ultra-7 stain applied to the logs. The final appearance depends in particular on the color selected and the application conditions. It is therefore recommended to test the product beforehand on a small area to assess the final result.
FREQUENTLY ASKED QUESTION: DO ALL CRACKS IN LOGS AND TIMBERS NEED TO BE FILLED?
No, it is not necessary to systematically fill every natural crack in the wood.
Particular attention should be paid to cracks that are oriented upward and are likely to retain rainwater. These should be regularly monitored and filled with Check Mate 2.
Cracks oriented downward generally retain less water and therefore present a lower risk. The primary goal is to prevent water infiltration and the accumulation of rainwater, rather than trying to fill every natural crack in the wood.
