"It's Time to Do a Little Spring Cleaning”by Tony Huddleston
With winter being almost over, and spring almost on us, it’s time to get out of the house and see what the ravages of winter have bestowed on your home, and do a little spring cleaning.
Depending where you live, winter can be a very unfriendly companion for your home. For instance if your home is located in areas prone to large amounts of snowfall, the snow can lay against the logs on your home for weeks. As the snow begins to melt during the day and re-freeze at night, the melted snow causes water to run into the season checks and small areas that rainfall normally doesn’t get into. The moisture inside the check can work its way into the wood substrate beneath the finish and allow the wood to become very wet.
Once the freezing process starts again, the trapped water will expand as it freezes beneath the finish and can, in some instances "pop" the finish off at the edges of the check. The wood then is unprotected and can start to suffer damage from ultraviolet light and repeated moisture.
Season checks that face upward and allow water to enter can not only lead to exterior finish problems, but they can also serve as a channel for the water to possibly work its way to the interior of the home. Water carried into the interior not only brings in unwanted moisture, but it also brings along with it unsightly tannin stains or "water stains" that will be visible and unsightly. These stains can be very difficult to remove, especially if the interior of the home is finished with a stain or sealer. Water stains on unfinished wood can normally be removed with a light scrubbing with Oxalic acid mixed with a mild non-ammonia type cleaner. If the wood is covered with a stain or sealer, it may be necessary to remove the finish, clean and re-finish the affected area.
The season checks that catch water on the exterior should be filled to prevent any further water entry with Check Mate or Energy Seal sealant. If the edges of the check are unprotected, they should be cleaned, lightly sanded and touched up to restore the protection.
Check the log ends for any evidence of darkening that would indicate the presence of water "wicking" into the grain of the end. Prolonged moisture problems lead to more severe problems if allowed to continue. To help prevent this problem, it may be necessary to lightly sand the log ends to remove any finish that may be left, and to remove any surface deterioration that may have occurred.
Some time should be allowed to promote drying of moisture that may be within the log ends, as you do not want to trap the moisture within. The ends should then be treated with Shell -Guard wood preservative to stop rot and decay fungi that may be present in the wood, allow dry time and re-stain.
Once the stain is dry, apply Log End Seal to help prevent any further water infiltration. Log End Seal is made from two Acrylic polymers that remain flexible to absorb log movement from seasonal changes, and provides a clear acrylic barrier to help prevent water entry into the log ends.
Caulking and chinking should be checked for integrity and adhesion at the interface of the sealant and the wood substrate. If the seal has broken between the wood and the sealant, it may provide a route for unwanted water entry and heat loss. With sealants there are normally two modes of failure, adhesive and cohesive. Adhesive failure occurs whenever the bond between the wood and the sealant is lost, and the sealant no longer is bonded to the wood or other substrate. With today’s quality high performance sealants, adhesive failure is almost a thing of the past on a properly applied sealant.
Most adhesive failures are due to improper application over excessive oil, dirt, or unsound surfaces. They can also happen whenever the incorrect type of sealant is applied. If adhesive failure is apparent, the faulty seal must be corrected by removing the product, properly cleaning the substrate, and re-application following the manufacturer’s recommendations.
Cohesive failure can be observed by evidence of tearing of the sealant, while adhesion is still sound. There are a number of reasons for cohesive failures, but most are the result of an improper application of one sort or another. Thin sealant applications are probably the most common, as it may be difficult to determine the depth a sealant is applied, and while the joint may appear to be sealed, there is not enough mass of material to absorb movement that may occur.
Three-sided adhesion of a sealant is also responsible for a great number of cohesive failures as well. In order for a sealant to work properly, it must not be applied in such a manner that does not allow for movement.
Good sealant applications dictate the use of a "bond breaker" that allows the sealant to pull away or "float" at the back side of the applied joint. This allows for movement of the substrate that can take advantage of the elongation built into quality sealants. In some cases, it may be impossible to use a bond breaker or backer rod beneath the sealant, as the situation may not allow it to be feasible. In that case, thickness or mass of the sealant will have to suffice for the application.
In the event of extreme movement, even the best of sealants may experience cohesive failure and require maintenance. Call and request a copy of our "Log Home Sealant Applicator Guide" for a practical explanation of sealant joint design and installation.
This Maintenance Article was originally published in Perma-Chink Systems News, Spring 2008. Published by permission.
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