Having began our career in log home restoration many moons ago, we've worked with all types of timber. This includes 200 year old 'seasoned' material, trees salvaged from the river bottoms and lakes, timbers air dried naturally for two years, freshly cut trees from the Eastern and Western US and Canada, standing dead, laminated logs and now vacuum-kiln material. We've seen them all. All this wood has one thing in common; It still shrinks and it still settles.
To what degree is subject to debate. Some of this shrinkage is measurable.
There are complex calculations to determine the amount shrinkage in fractions of an inch based on moisture content and species. But these aren't adjusted for real-world application such as the percentage of "heartwood" vs. sapwood", the altitude or latitude in which it was grown (shortness of seasons), the tightness of rings (old growth vs. new) and the type of cut (boxed heart vs. free of heart center---FOHC). If you can dry the timber down to 12% consistently, you will see minimal shrinkage thereafter. But shrinkage from moisture only accounts for HALF of the settling.
The other half comes from compression. This is driven by the weight of the roof (with a full snow load). It is helped by the weight of the second (and third) floors. And it is accelerated by the use of throughbolts and compression springs. The longer you take to build a home and the later you design and install the finished stair system, the better.
Some of this shrinkage and settling is unpredictable. Relative humidity, snow loads, prevailing winds, exposure to rain and sun, type of fasteners, throughbolts, adjoining structures, covered up screw jacks, hidden fasteners, window & door trim and interior partitions nailed up tight. All real-world issues that should be managed.
We have seen 200 year old bone-dry material in a dovetailed system compress and settle over one inch in nine feet after the weight of the floor and roof is applied. For this reason, we still engineer for shrinkage and settling in our log homes, even if HeartDried down to 12% moisture at the core. In fact, the new International Residential Code calls for log home manufactures to detail for shrinkage if they experience more than 1/2" settling in every 8'-0" of height. It is one thing to detail it, and another to see that it gets done.
Chink me now, or chink me later! In the old days, there was mortar mix and chicken wire to use between the hewn logs. We would painstakingly splice and dovetail these old timbers and make certain it was perfect. During the higher humidity summer months, these joints would swell tight. Come winter when humidity dropped, these same joints opened up ever so slightly.
Then came PermaChink™. Making the home weather tight around the chink joints became easy. It stretched and compressed and moved with the seasons. Attractive colors were added the battle of the chink space was solved.
But what about log-on-log? Over the years, we've seen many folks initially object to "that white stripe" and rule out our chink style for someone else's log on log. Then after two good years of living in the home and dealing with real-world issues, they're back to caulking or chinking the seams to make it perfectly weather tight.
A solution for these log-on-log clients has finally arrived in custom Energy Seal™ colors to match the Lifeline stain. No more worry about last minute touch up or sealing gaps in trim with caulking that doesn't match. For those who don't want the color and performance of chinking, they now have an attractive alternative with Energy Seal™. A case of interior and exterior should be sent with every home sold. Maybe the old saying should change to "Chink me now, or Seal me later"?
http://www.hearthstonehomes.com/
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