Interlock Joinery System

Our proven, single tongue and groove design is part of the Real Log Homes® Interlock™ Joinery System, which continues to keep thousands of Real Log Homes brand log homes as weather-tight and draft-free as possible. 

In log home construction, the size of the tongue and groove (or baffle and channel) of each log is a vital part of any tongue and groove log joinery system - the system that effectively keeps weather out and comfort in. To be effective over the lifetime of your home, the tongue and groove should be part of a system, not heavily reliant on caulking or other material that can be compromised over time by the elements.

A common fallacy about tongue-and-groove joinery is that if one tongue is good, two must be better. Not true! When properly designed, a single tongue and groove system has several advantages. The Real Log Homes single tongue and groove design, one of the largest in the industry at two inches wide and 3/4” tall, allows room for a larger gasket. That means superior protection from the elements. Because there’s only one tongue, it also means more room for safe fastening on the surface of each log. Our larger, single tongue also reduces its risk of damage during shipment and construction.

In a double tongue and groove system, each tongue must be smaller so that the log surface can accommodate two tongues rather than one, while providing adequate area for fastening. Smaller tongues result in the use of smaller gaskets and/or beads of caulk. We’ve found the combination of smaller components can create greater risk of water finding its way past the first smaller tongue and then becoming trapped between the two, risking deterioration and/ or mildew. 

The Real Log Homes single tongue and groove system eliminates the possibility of water being trapped within the logs’ joinery system. Our system works by allowing a specially formulated foam gasket to be compressed within a predetermined tolerance for a tighter fit. In combination with the gasket, an “air-lock” created by the beveled edge of the tongue fitting into the groove of the log above diffuses and relieves outside air pressure, providing superior draft protection. This system is effective without heavy reliance on caulk.