SECOND FLOOR SYSTEM

                Read this entire section before beginning any phase of second floor installation.  Check your Materials List (copy in blueprints and in warranty packet) to determine the size and length of floor joists and girder beams shipped.  Be certain to use the proper length for each application as specified on the Materials List.  Study the blueprints as they should be the determining factor as to proper installation of the second floor system.

                Determine how your second floor joists will be installed.  There are basically four alternatives.

1. Let second-floor joists rest on top of log walls and on top of girder. Most common method.

2. Let second-floor joists rest on top of log walls and notch into girder.   Good for raising height of center girder beam.  Check your local building codes for compliance.

3. Notch second-floor joists into top course of logs and into girder.  Usually require extra courses of logs to yield same 8-foot ceiling height.  Check your local building codes for compliance.

4. Notch second-floor joists into top course of logs and rest on top of girder.  Usually requires extra courses of logs to yield 8-foot ceiling height.

If you plan to use notches, check your blueprints and read through this entire section carefully to determine where to locate the joists in relation to the girder and top log course.  It is best to notch the girder and top course of logs before installation.

                The remaining instructions on second floor system installation will be based on Scenario No. 1 where second-floor joists will rest on top of the log walls and on top of the girder beam, as this is the most common method employed by our customers.

                The first step in installing second floor systems is to mark the top course of logs as to the locations of all rafters and second-floor joists.  It is vital that you closely follow your blueprints throughout this procedure and let the blueprints be the determining factor as to rafter and joist location.

                Notice that the end logs on the top course extend beyond the log wall corner, more than any other logs.  This extension is designed to support the end roof rafter.  The first rafter will sit on the very end of the extended log of the top log course.  This rafter is called the barge rafter and will serve as the roof overhang support.  Its outer edge should be flush with the outer end of the extended log.

                For the second rafter location, check your blueprints for the rafter spacing required for your home.  For the sake of discussion we will use 48” on center (“O.C.”)  Measure along the top log course the specified rafter spacing distance measuring from the outside edge of the barge rafter location.  This spot marks the location of the edge of the second rafter.

                Second-floor joist locations should now be marked in like fashion.  Check your blueprints for spacing (for the sake of discussion, 24” O.C.)  The first joist should sit flush with the inside face of the end log wall as shown below.  The second joist location should be marked immediately next to the second rafter location previously marked.  The third joist will be marked 24 inches further down and should be halfway between rafter #2 and rafter #3.  The fourth joist will then be marked 24 inches further down and will be located immediately next to the third rafter, rafter #3.

                To further clarify, if rafters are on 4-foot centers and joists are on 2-foot centers, then every other joist will sit next to a rafter.  The rafters and joists will then be fastened to the log wall and to each other giving great structural stability to the home.  To install rafters and joists in any other fashion may compromise the stability of the home and is not recommended.

                The second floor joists will sit on the log wall on one end, and on a 6”x12” girder beam toward the center of the house.  The girder beam will run perpendicular to the floor joists and will be supported on one end by a post.  The other end will notch into the end log wall.  Before actually installing any framing for the second floor system, you may find it best to clean, sand and stain the beams.  A 1:1 solution of bleach and water works well for cleaning.

                The next step in second floor installation is to determine the exact location of the girder beam and adjustable support posts from the blueprints.  Once determined and double-checked, cut a three-inch deep notch into the top course or courses of the end log wall for one end of your girder beam to rest in.  Locate a post under the other end and brace girder so it will stand alone.  Join the next girder (if applicable) to the end of the first using the splicing and fastening methods shown.  Keep the center girder beam square with the house.  Posts and splices must be precisely located as per the blueprints over foundation piers so the second floor will be supported all the way through the foundation.  Furthermore, make sure there is solid wood blocking under the plywood subfloor deck where the support post sits.  This blocking also must be supported by solid, rigid posts or piers all the way through to the pier footers as indicated on your foundation plan.  Make sure that the final posts installed under the 6x12 girder beams are adjustable so the center of the second floor may be lowered to compensate for log settlement.  All Tennessee Log Homes’ second floor systems include screw jack assemblies, 6x6’s and 2x4’s with which you may construct adjustable posts.  For detailed information on log settlement, see the section on Interior Partition Walls later in this manual.

                Once all girder beams are installed and properly supported and braced-off, mark off the locations of the second-floor joists on top of the girder.  Make certain that the joist locations on the girder correspond to the locations previously marked on the log walls.

                You are now ready to begin cutting the floor joists to length and installing.  The joists will run from the center of the girder to near the exterior of the log wall.  They will not run all the way out to the edge, however, and should be inset approximately 3/8 inch.  This inset is left so that a piece of log profile siding may later be used to cover the ends of the joists (snow-blocking).

                To precisely determine the amount of inset needed, actually fit a piece of siding on top of the log wall.  Make sure the exterior face of the siding matches that of the log wall, then measure the inset.  The length of the joist, therefore, is measured from this point of inset back to the center of the girder beam.  Using this measurement, cut one joist and make sure it fits properly.  Get a measurement for each joist before cutting.

                Chisel away the tongues on top of the log where the joists will sit.  Joists and rafters should sit on the log top, not on the tongues.  Joists should be fastened to the log wall by drilling a 3/8-inch hole through the joist and spiking the joist to the log with a 10-inch spiraled spike.  Joists butting together over the girder should be joined together using metal strapping and spiked down to the girder with 10-inch spikes as well.

                After the girder and joists are properly installed, you should again consider your electrical system.  Wiring for overhead lights, fans, etc. (under the second floor) and switches need to be run now, before the second floor decking is installed.  You should have your electrician present to supervise this installation.

                Wiring should be run along the top of the second-floor joists by recessing the wiring into the of the beams.  Use a router or a chain saw to cut the recesses.  Also, holes should be drilled vertically through the beams to bring wiring down through for overhead lighting underneath.  Be certain that all wiring needed is run in this manner before installing your second floor decking.

                Check the lengths of 2x6 tongue & groove decking you received with your package.  If you receive any 10’ or 14’ lengths, use these for second floor decking, saving any 8’, 12’ and 16’ for roofing.  10’ and 14’ lengths work with joists on 2’ centers, but not with rafters on 4’ centers.  Begin to move decking onto the subfloor and prepare for installation.

                The 2x6 tongue &groove decking should not be installed within 2 feet of the front and rear log walls until the roof rafters are installed.  The roof rafters will pass through the plane of the second floor decking and sit on the top of log walls.  If you install decking all the way out, you will not have room to install the rafters on top of the log wall.  Rafter are not to sit on top of the second floor system.  You may complete the second floor decking installation once the house rafters are installed.

                In the case of a shed dormer, however, the rafters will sit on top of the shed dormer studwall.  The shed dormer studwall will sit on top of the decking of the second floor.  Therefore, complete the second floor decking installation where the shed dormer will be constructed.

                Install the tongue & groove decking with 16 penny-coated nails by toe-nailing the tongues of each piece to each joist.  Be especially careful not to nail into any wiring recessed in the top of your second floor joists.

                Keep the second floor decking covered with plastic sheeting until the roof system is completed.  It is very important to keep kiln-dried tongue & groove products as dry as possible.