These thru-bolt plates are 2½" x 3½". The round rod welded to the plate has a 1¼" outside diameter and is 3" long. This piece fits into the pre-drilled thru-bolt hole that runs through the log walls. An 1½" Self-Feed Bit can be used to widen the thru-bolt hole to accommodate the plate rod. The builder secures it into the bottom of the base log course and stacks the wall. When the wall logs are stacked, the pre-drilled thru-bolt holes are lined-up and a 1/2" threaded rod is dropped in from the top. The tapered top allows the threaded rod to center properly and start. Made in the USA.
The most common bolts used in log construction are called thru-bolts. Thru-bolts are threaded rods that run the full height of the log wall or stacked wood − through all log courses − and are held by a nut and washer on each end, beneath the subfloor or sill log and above the top log course. Because of their long lengths, we recommend picking up the threaded rods through your local hardware store.
Thru-bolt fastening offers the big advantage of allowing logs to move along the bolt as wood seasons, accommodating the natural expansion and contraction that will ordinarily occur over time with changes in humidity and heat throughout the years.
You may need to invest effort in occasional manual re-tightening, to maintain pressure on each end of the thru-bolt. This will create a compression force that will help to keep the log wall tight, waterproof and secure. In the event of a storm with high winds or an earthquake, mudslide or other calamity, thru-bolt fastening system acts as a tension rod, limiting log separation and helping to maintain the integrity of the overall construction.
