Avoid these common framing mistakes
Check out these all-to-common framing mistakes and what you can do to prevent them.
Panel spacing
One of the most common framing mistakes − and one of the easiest to avoid − is improper panel spacing. Like all wood products, plywood and OSB panels can expand or shrink slightly with changes in moisture content. If you install panels too tightly, there is no room for expansion, which can lead to buckling.
To avoid this and frame it right, leave a ⅛-inch space between the edges and end joints of plywood and OSB panels. There’s a simple trick to this: A 10d box nail is about ⅛ inch; if it fits snugly between panels, there’s enough space. For roof applications, use spacer-type panel edge clips.
Subfloor installation
Common subfloor installation mistakes can lead to annoying squeaks and nail pops that damage the finished floor.
Nail “pop” or “backout” sometimes occurs when green (wet) lumber shrinks as it dries. The nail point stays put while the lumber shrinks along the shank, exposing the nail head. Repeated wetting and drying of the wood also can cause nails to pop.
To avoid nail pops, use dry lumber or engineered wood framing that’s manufactured in a dry environment. Even kiln-dried lumber has enough water left in it to cause some shrinkage.
When using plywood underlayment on a subfloor, use nails approximately as long as the total thickness of the subfloor and underlayment layers.
If you’re using a pneumatic nail gun, apply foot pressure near the fastener to ensure contact between the underlayment and subfloor. Don’t overdrive or underdrive fasteners. Ring- or screw-shank nails are recommended. Attach the panel to a clean, level framing surface.
Framing hangers
When framing hangers or connectors are attached to the top of supporting framing members, shims or furring strips may be needed between the hardware components to make the framing surface flush.
Otherwise, gaps between sheathing and framing could result in nail pops when the sheathing is subjected to construction loads or foot traffic.
Flooring installation
Noisy floor systems is one of the most common framing mistakes. To help prevent noisy or buckling floor systems:
- Use dry or engineered lumber, both of which are more dimensionally stable.
- Consider the applied load, joist spacing, finish flooring material and floor system.
- Space panels ⅛ inch from all edge and end joints.
- Allow panels to acclimate to the indoor temperature prior to installation.
- For a glued floor, use an adhesive meeting APA Performance Specification AFG-01 or ASTM D3498. Spread enough glue for only one or two panels at a time; ensure the surface of the supports is clean and dry before applying the glue. Apply a ¼-inch-diameter bead in a continuous line or a serpentine pattern in wide areas. Ensure the panels are set in wet adhesive and finish nailing before the glue sets.
- Choose the correct nail size and spacing for the joist spacing and panel thickness. (Refer to APA – The Engineered Wood Association for attachment schedules and fastener recommendations).
Storage
To ensure optimum performance and avoid common framing mistakes, OSB and plywood must be stored and handled properly to protect them from damage.
In transit, ensure your supplier takes precautions to protect panel ends and edges during shipment, especially with tongue-and-groove and shiplap-edged products. If panels are shipped on open truck beds, they should be covered with a tarp. For open railcar shipments, wrap should be used to keep panels dry and clean.
On the jobsite, store panels in a covered area. Keep sanded panels and appearance-grade products away from high-traffic areas to prevent damage to surfaces. Use lumber to hold down the top panel in a stack to reduce warping. If moisture absorption is expected, cut steel bands on bundles to prevent edge damage.
If panels will be stored outside, stack them on a level platform supported by at least three 4x4s to keep them off the ground. Place one 4×4 in the center and the other two 12 to 16 inches from the ends. Never leave panels in direct contact with the ground.
Cover the stack loosely with plastic sheets or tarps. Anchor the covering, but keep it open and away from the sides and bottom to ensure good ventilation. Tight covers prevent air circulation and when exposed to sunlight, can promote mold or mildew.
For more information on these and other tips, visit apawood.org/buildertips.
−By Mary Uher, engineered wood specialist with APA – The Engineered Wood Association