| Introduction | | | | likelihood that the seal will break away from one or |
| With its thick walls of solid wood, a log home is one | | | | more of the points of adhesion. Placing a backing rod |
| of the best-insulated buildings in which you could | | | | inside the well With this principle in mind, any backing |
| choose to live. But the nature of a log home's | | | | materials included in a caulk joint should provide a |
| construction also presents a unique challenge: the | | | | surface to which the caulk does not adhere. Doing so |
| opportunity for air to pass through the gaps | | | | allows the caulk to remain at its most elastic. |
| between the logs. | | | | Principle 3: Create a Caulk Well |
| Fortunately, air infiltration is a challenge that's easily | | | | Superior caulks have enough elasticity to absorb 25 |
| met, thanks to caulking, the general term for the | | | | to 50 percent of the total movement in the joint |
| seals that are introduced between logs. With the | | | | they fill. To allow for that movement, caulk joints |
| right caulking method, or "caulk joint" as it is generally | | | | require "wells," spaces that allow the joint to absorb |
| termed, a log home can achieve thermal efficiencies | | | | that movement. For a reliable seal, the caulk well |
| to rival those of any building method. | | | | should be two to four times larger than the |
| Two key elements are essential to effective caulking. | | | | movement that is anticipated for that joint, thus |
| First, the caulk used must form a "wet" seal, one | | | | reflecting the 25 to 50 percent absorption properties |
| that adheres to the wood surfaces rather than just | | | | of the caulk being used. Obviously, the greater the |
| filling the gaps between them. And second, it needs | | | | movement expected in a particular joint, the larger its |
| to be elastic (a quality sometimes referred to as | | | | caulk well should be. Log homeowners can also take |
| "memory"), either stretching or compressing as the | | | | comfort from the fact that high-quality caulks |
| shapes of the logs themselves subtly move through | | | | currently being sold are capable of absorbing far |
| natural expansion or contraction. | | | | greater movement than that for which they are |
| Another way of thinking about a caulk's | | | | rated. |
| effectiveness is in terms of "adhesion" and | | | | Principle 4: Apply Caulk Under Optimum Conditions |
| "cohesion." Good adhesion means that the caulk | | | | Because logs expand or contract in response to |
| sticks to the log well. Good adhesion means that it | | | | temperature and humidity, the climate conditions at |
| holds together well under stress. Obviously, a balance | | | | the time caulk joints are applied will affect the seal |
| of both properties is necessary for a caulk to work | | | | formed. On a very hot, humid day, for example, a |
| properly. | | | | joint will be at its smallest, since wood expands under |
| With those elements met, four principles govern the | | | | such conditions; so caulk applied at such a time will |
| most efficient caulk joint design: caulk depth, points | | | | later be subject to the maximum stretching. By |
| of adhesion, a caulk "well," and the conditions under | | | | contrast, a joint will be at its largest on the coldest, |
| which the caulk is applied. Each principle is fairly simple | | | | driest of days; so caulk applied then will later be |
| to grasp, and understanding them all will help anyone | | | | subject to the maximum compression. With this |
| buying, building, or restoring a log home make the | | | | principle in mind, it is wise to select a caulk with |
| right energy-efficient decisions. | | | | properties that best suit the range of local climate |
| Principle 1: Apply the Right Caulk Depth | | | | conditions, and to apply it at the most stable, least |
| In general, the depth of caulk in a joint is more | | | | extreme point in the climate cycle. But smart log |
| important than the width of the caulk's application. | | | | home builders will also apply caulk at optimum times; |
| Why? Put as simply as possible, the most critical | | | | for example, sealing caulk joints on the cooler side of |
| factor is that the caulk have enough mass at any | | | | a home will work most effectively on a warmer day, |
| given point to absorb any movement in the logs. As | | | | while those on the side of a home that gets more |
| a rule, whatever its width, the depth of a caulk joint | | | | direct and prolonged exposure to sunlight would best |
| does not need to be any more than 1/2 inch or any | | | | be sealed on a cooler day. |
| less than 1/4 inch. Also, a deeper joint is preferable | | | | Conclusion |
| to one that is too thin. | | | | By aiming to apply all four principles described above, |
| Principle 2: Provide Two Caulk Adhesion Points | | | | you'll maximize the effectiveness of your caulk joint |
| Caulk works best when it adheres only to two | | | | seal. That may require you and your builder or |
| elements, namely the two logs between which it is | | | | contractor to implement sealing techniques that go |
| applied, so that the seal will hold if and when any | | | | beyond the most obvious and simple solutions. Keep |
| movement occurs in the logs. Adhesion to three or | | | | these guidelines in mind, and you'll thus enjoy the |
| more points, by contrast, would cause the caulk to | | | | maximum benefits of log homes' superior insulation |
| be pulled in multiple directions, thus increasing the | | | | and energy-saving capabilities. |