Wood Truss & Wall Panels

Considerations for Building with Wall Panels

WTCA (Wood Truss Council), in cooperation with the Building Systems Council of NAHB (National Home Builders), sponsored the Framing the American Dream® project to better understand wood framing. It was the first time two identical house plans were completely framed using two different methods - one stick built, and the other with wood trusses and wall panels (structural building components) exclusively.

Here is what was learned from this project concerning framing with wall panels specifically:

In our project, the wall designs were not optimized, with studs designed at the specific spacing required for the applied roof and floor loads. Generally, with proper planning and a fully engineered design, less lumber will be required for most projects which utilize wall panels.

• Placement plans greatly simplify the wall panel installation process by clearly identifying each panel and its correct location.
• Material quality is controlled and you are assured the use of high quality material.
• Wall are square.
• Proper nailing patterns are used.
• Studs and headers are designed to support applied loads.
• Sheathing and building wrap can be applied at the time of manufacturing saving time in the field.

Manu dimensions that are necessary for the successful use of wall panels are not on the plans. To maximize wall panel efficiency take a few minutes to review this checklist. Because of the precise engineering and panel design involved Classic Truss will need to know this information before manufacturing your panels. We can help you determine these answers from your building plans.

Heights

• Are wall heights nominal or standard?
• Provide all elevations. Different ceiling heights do not necessarily mean different all heights.
• Are there any short walls (e.g. around the stairwell)?
• Are there floor level changes requiring changes in wall height?
• What are the garage foundation curb heights?

Openings

• What are all the rough opening sizes?
• Are transom/half-round windows shown clearly over windows and doors?
• Who is the exterior door manufacturer and what is the exterior door type?
• What are the door rough opening sizes?
• What is the tub clearance? This is best expressed as the overall stud-to-stud distance.
• What is the fireplace chase wall height and sheathing?
• What is the stair rough opening size?
• What is the interior door and window casing width? With wide trim, additional clearance may be needed between the rough opening and perpendicular walls.

General

• Should the wall panels be built as drawn or as reversed?
• Are dimensions out-to-out of stud or out-to-out of sheathing?
• When the plans reference brick or stone, be sure to supply all necessary dimensions. Often the plans do not indicate the distance from the face of the brick to the face of the stud.
• What are the header sizes for interior bearing walls?
• What is the wall sheathing type?
• What is the corner bracing type?
• Should Classic Truss provide treated bottom plates for installation on concrete or masonry?
• What are the placement dimensions for all interior walls, including skewed walls?
• Will there be multiple studs for concentrated loads from girders, beams, etc.?
• Will there be pockets for racks/beams? What are the location, size and elevation od these pockets?

Don't worry too much if you need help determining some of the items above. Classic Truss and Wood Components are here to help. We understand the industry and can help you every step of the way!

Recommended Procedure* for Installation of Wall Panels

* In most cases Classic Truss installs the wall panels the we manufacture. This is what we call our turn-key solution and will assure efficiency and accuracy. However, if you have a framing crew that you would like to use then, for your convenience, here are a list of the basic steps. This list is to give you a better idea as to how a home built with wall panels is constructed on the jobsite and my no means should be a considered and exhaustive list.

• Step One: To get the greatest benefit out of wall panels it is absolutely critical to start with a foundation that is level and square. Anything less will reduce the economic benefits that can be gained through the use of wall panels. If the foundation is not level or square, plan for any adjustments before the panels are manufactured. It may be necessary to start wall panel placement at the center point of the foundation, to equally adjust for any measurement error.
• Step Two: Note all measurements required before installation. (See checklist above.)
• Step Three: Measure the sub floor or slab. Compare this measurement with the dimensions on the placement plans. Check for all floor openings (e.g. stairway, fireplace, etc.)
• Step Four: Review the wall panel stacks that were delivered and adjust them for placement. Although we try to determine in what order you will need each wall and stack them accordingly, we may not always succeed exactly. Sometimes we have to stack the walls so that they can be safely delivered to your jobsite.
• Step Five: Chalk a line at the inside face of the exterior walls.
• Step Six: Write the panel numbers on the floor, following the wall panel layout, in order to indicate the location of each wall panel.
• Step Seven: Set the two exterior wall panels and fasten together tightly. Nail the wall panels together at the top, middle and bottom of the end studs.
• Step Eight: Brace each wall panel as it is set. Use 2x4s anchored to the floor or ground to stabilize each wall panel. This very important for wall stability.
• Step Nine: Continue setting additional wall panels leaving a couple of exterior wall panels out, to allow the interior walls to be brought in. A few important details to keep in mind:
  • It may be necessary to shim to compensate for slab or sub-floor issues. Shim so that there is full contact between the wall panel and slab or sub-floor.
  • Extra caution is required with walls that have plumbing (water).
  • If the sub-floor slopes and you "rack" the walls to get the studs vertical (plumb), the openings will no longer be square.
  • Long, end-to-end runs of wall panels MUST be butted together tightly by hand or mechanical means or the run will be too long. This can often be compensated for up-front by purposely under sizing each wall panel by 1/16" or even 1/8".
• Step Ten: Continue setting interior wall panels working from the farthest end toward the opening of exterior wall panels that are not yet set.
• Step Eleven: After setting all interior wall panels, finish setting the remaining exterior wall panels.
• Step Twelve: Install the upper top plates. Whenever possible, overlap top plates by at least one stud spacing.
• Step Thirteen: Check all fastenings at joints, and add additional bracing as necessary to maintain wall stability.

For garage and window headers at the same location as house windows, increase the height of the garage window by the difference between the height of the house foundation and garage floor.

Garage door and swinging door headers are located at their "standard" heights, unless garage walls are to be set on a masonry curb wall that extends above the height of the garage floor.