The Simpson HHDQ11-SDS2.5 Heavy Holdown is designed to deliver high-load performance with minimal deflection and quick installation. Featuring a unique seat that reduces deflection above the mudsill, this holdown comes with Strong-Drive SDS Heavy-Duty Connector screws - eliminating the need for bolts and simplifying setup. Built ruggedly from thick-gauge steel, it's the go-to anchor for demanding structural connections.

Key Features

• Unique raised seat design minimizes deflection under load when installed above the sill plate.
• Includes Strong-Drive SDS Heavy-Duty Connector screws for fast, slip-resistant fastening that preserves more of the post’s net section compared to bolts.
• Screws can be installed flush or raised - no load reduction either way.
• No need for stud bolts or countersinking at openings - streamlines the install process.
• Constructed from heavy-duty 7-gauge steel and finished in corrosion-resistant gray paint.

Applications

• Ideal for high-load connections in wood framing - especially in shear walls, braced-wall panels, and mass-timber structures where uplift resistance is critical.
• Its elevated seat design makes it perfect for installations raised off the mudsill, minimizing deflection at critical connection points.
• Compatible with both new construction and retrofitting - works well in spaces where eccentricity or alignment is a concern.

Installation

1. Position the holdown directly on the sill plate or slightly raised above it as needed.
2. Use the included (24) 1/4" × 2 1/2" Strong-Drive SDS screws - no washers required.
3. Install the screws with a low-speed, high-torque drill outfitted with a 3/8" hex-head driver.
4. Ensure proper alignment and secure fastening in all provided holes to guarantee full load capacity.