INTERIOR PARTITION WALLS AND LOG SETTLEMENT

                Log homes will naturally settle to some extent; therefore, proper log home construction must incorporate preventive mechanisms to protect various components of the home from damage.  For instance, the previous section on exterior door and window installation describes one such mechanism, the “floating” rough opening frame, which protects windows and doors.  Another protective device employed in proper log home construction is the “floating” interior studwall.  This protects interior main floor walls from being stressed in any way by the natural log settlement.

                There are two basic aspects of the floating studwall that need be discussed.  First, those main floor studwalls which attach to log walls must allow the log wall to settle without moving or binding the studwall.  This is accomplished by cutting grooves in the stud which join the log wall and nailing the stud to the wall through these grooves.,  This adheres the stud to the log wall, but allows the log to move independently of the stud.  Another method is to sandwich strips of 1/2 inch plywood between two 2x4’s (or between three 2x6’s for a 6” studwall - shown) and to nail through the slots created by the plywood.

                The second aspect of the floating studwall concept allows for the second floor system and/or roof system to settle downward without binding the main floor walls underneath.  For example, if the log walls settle one inch, then the secon floor system and roof system which sit on top of these log walls will also settle one inch.  This movement must not bind the studwall.  This is accomplished by leaving about two-inches of space between the top plate of the studwall and the final top plate which would be attached to the bottom of the second floor decking, joists, or girders.  The location of the studwall is marked on the subfloor and a 2x plate is attached to the bottom of the second floor directly above the studwall location.  The interior studwall is then constructed in a normal fashion, except that it stops two inches short of the plate attached to the bottom of the second floor.  Sixty-penny nails are used to attach the studwall to the plate on the bottom of the second floor by nailing through predrilled holes in the top plate and into the 2x mounted above.  This prevents the wall from moving forward or backward or from side to side.  However, if the logs settle downward, the second floor system is not held up by the studwalls, for its weight will simply push the sixty-penny nails downward and will not bind the studwall.  Interior wall coverings, such as sheetrock will go up to the top plate of the studwall only.  The space above will be covered with a trim board that is nailed to the 2x plate on the bottom of the second floor.  The trim board will fit flush against the sheetrock below but is not nailed to the sheetrock or studwall.  The trim board will then move as the second floor moves and will simply slide by the wall covering without binding it.

                For floating studwalls which run perpendicular to the second floor joists, the plate nailed to the bottom of the second floor may not be necessary.  In this case, the sixty-penny nails can be attached directly to the bottom of the second floor joists.  Or, in the case of a wall under the center second floor girder beam, the floating studwall may be fastened directly to the bottom of the girder beam.  However, a 2x plate attached to the bottom of the girder may be needed as a nailable base for trim boards to be installed later.

                The adjustable posts previously installed under the center girder beam are yet another safeguard against damage from log settlement.  This mechanism prevents having an unlevel second floor system by allowing you to lower the center of the second floor system if it gets out of level due to the log settlement.

                It is best to construct 2x6 studwalls where you plan to run large plumbing, air conditioning, etc. upward through the wall.  All studwalls on the upper floor are built rigid as in a conventional home.  There should be no space left above second floor walls.