• Post Size: Accepts true 4x4 (3.5" × 3.5") lumber; optional 4x6 reducer available 
• Adjustment Range: 12" total (±6" from center set height) 
• Height Settings: Infinite adjustment via threaded rod; locking with four ½" bolts 
• Load Capacity: 12,000 lbs compression / 4,500 lbs uplift (with ICC or Model 3 76mm+ screws) 
• Base Plate: 8" × 8" × ⅜" with pre-drilled holes for optional seismic tie-downs 
• Compatible Screws: All AGS 76mm and 114mm ICC-certified and Model 3 screws (open-top or U-bracket versions) 
• Options: Standard height (12" range), Extended height (18" range for steep slopes), Powder-coated black or custom colors, 4x6 reducer kit, Seismic/wind tie-down bracket kit 
• Weight: 18 lbs (standard version)

4x4 Adjustable Height (Post Base for American Ground Screws)

ProductDetails

The 4x4 Adjustable Height Post Base instantly turns any American Ground Screw into a fully code-compliant, height-adjustable foundation for decks, pergolas, carports, tiny homes, and elevated boardwalks. With a full 12 inches of vertical adjustment (±6" from center), you can level posts perfectly on uneven or sloped terrain without shims, cutting blocks, or extra labor. The heavy-duty saddle accepts standard 4x4 lumber (3.5" actual) or 4x6 with optional reducer, locks with four galvanized bolts, and supports loads up to 12,000 lbs in compression when paired with ICC-certified or Model 3 screws.Contractors love it because it eliminates concrete piers completely while still passing inspection in all 50 states. Install the ground screw, drop in the post base, insert your 4x4, level in seconds, tighten four bolts, and you’re done—no curing, no waiting, immediate loading. The open design sheds water and debris, prevents rot at the post base, and allows full post replacement years later without touching the foundation. One accessory delivers perfect height, perfect leveling, and decades of maintenance-free performance.

Material & Care

Constructed from heavy-duty, corrosion-resistant alloy steel with precision-machined hex fittings for durability under extreme torque loads. Hot-dip galvanized finish per ASTM A123 standards protects against rust and wear in harsh outdoor environments. Care involves routine inspection for wear after each use; clean with mild solvent to remove soil residue, and store in a dry, protected area to maintain peak performance. Avoid exposure to chemicals or impacts that could compromise the galvanization.