Hold-Down (Holdown)

When wind pushes on a wall, the wall wants to do more than slide. It wants to tip over, lifting at one end and pressing down at the other. A hold-down (often written holdown) stops that lift. It is a steel connector that bolts, nails or screws to the end post of a shear wall and anchors it to the foundation or to the framing below.

Simpson Strong-Tie, the largest maker of these connectors, describes the hold-down's job as resisting the overturning caused by sideways loads. Its testing also found that restraining the end posts made the whole wall stiffer and stronger, because the sheathing nails along the edge start doing their full share of the work.

Hold-downs come in two basic types. A strap hold-down is a long steel strap set into the concrete when the slab or stem wall is poured, then nailed to the post after framing. A post-installed hold-down is a heavier bracket fastened to the post and to an anchor bolt that was cast into the concrete. Either way, the location has to be known before the pour, so hold-downs are drawn on the foundation plan and checked at the foundation and framing inspections. The International Residential Code calls for them on several of its narrow-wall bracing methods, such as portal frames beside garage doors.

For example, a two-story custom home in Scottsdale with a wide garage door may need strap hold-downs at both sides of the opening. If the strap is missed at the pour, the fix is an engineered retrofit anchor drilled into the concrete, which costs time and an engineer's sign-off. For the code background, see IRC R602 wall construction and bracing and the glossary entry for a braced wall panel.