The Simpson MPB66Z ZMAX Moment Post Base for 6x6 Posts is an engineered connector from Simpson specifically designed to provide moment resistance for wood columns and posts. Its innovative sleeve design encapsulates the post and prevents it from rotating at its base when lateral loads are applied at the top, giving specifiers and contractors greater design flexibility and the opportunity to reduce the need for bracing - creating more unobstructed views. This ready-to-install, off-the-shelf solution eliminates the time and expense involved in designing, calculating, and ordering custom-fabricated parts, making it a practical choice for decks, pergolas, carports, and open-structure framing where clean sightlines matter.

Key Features

• Internal tabs provide the code-required 1 in. post standoff - keeps the wood post elevated above the concrete surface, helping prevent rot from standing water and ground moisture contact.
• Stamped indicators and internal tabs identify the required concrete embedment depth - takes the guesswork out of placement and helps ensure a code-compliant installation every time.
• Strategically placed holes allow template attachment - simplifies layout and positioning during concrete pours, saving time on the job site.
• Optional obround holes accommodate trim material attachment - gives contractors a cleaner finished appearance without additional fabrication or modification.
• Additional holes at the embedment line allow standing water to exit and serve as a visual inspection point - supports long-term performance and makes it easier to spot potential moisture issues after installation.
• One-piece design - reduces the number of components to manage and streamlines the installation process from start to finish.
• Made from 12-gauge steel with ZMAX galvanization - delivers extra corrosion resistance suited for exterior applications and use with pressure-treated lumber.
• Includes 1/4 in. x 2-1/2 in. Simpson Strong-Tie Strong-Drive SDS Heavy-Duty Connector screws - everything needed for fastening arrives with the connector, so there are no separate trips for compatible hardware.

Why This Product

• Moment resistance without custom fabrication - the sleeve design actively prevents post rotation under lateral loads, a performance capability that would otherwise require expensive, time-consuming custom-engineered hardware.
• Designed to open up your structure - by reducing or eliminating the need for supplemental bracing, this post base helps architects, designers, and builders achieve cleaner, more open framing layouts with fewer visual obstructions.
• Built-in moisture protection details - the code-required 1 in. standoff, drainage holes at the embedment line, and ZMAX corrosion-resistant coating work together to extend the service life of both the connector and the post in demanding outdoor conditions.
• Engineered and tested for consistent, reliable performance - as an off-the-shelf Simpson product, the MPB66Z has been engineered and tested to defined load values, giving specifiers and inspectors the documentation confidence they need without relying on field-fabricated solutions.

Specifications

• Model Number: MPB66Z
• Member Size: 6x6
• Gauge: 12
• Width: 5-9/16 in.
• Height: 7-1/4 in.
• Coating/Finish: ZMAX
• Country of Origin: United States
• Installation Fasteners: Install with 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws (included)

What's Included

• 1/4 in. x 2-1/2 in. Simpson Strong-Tie Strong-Drive SDS Heavy-Duty Connector screws

Frequently Asked Questions

What makes the MPB66Z different from a standard post base?

Unlike standard post bases, the MPB66Z features an innovative sleeve design that encapsulates the post and provides moment resistance, preventing the post from rotating at its base when lateral loads are applied at the top. This can reduce or eliminate the need for additional bracing and create more unobstructed views.

Does the MPB66Z include the required installation fasteners?

Yes. The MPB66Z includes 1/4 in. x 2-1/2 in. Simpson Strong-Tie Strong-Drive SDS Heavy-Duty Connector screws needed for installation.

How does the MPB66Z protect the wood post from moisture damage?

Internal tabs provide the code-required 1 in. post standoff, keeping the wood post elevated off the concrete to help prevent rot from standing water and ground moisture. Additional holes at the embedment line also allow standing water to exit and serve as a point of visual inspection.

Is the MPB66Z suitable for use with pressure-treated lumber and exterior applications?

Yes. The MPB66Z features ZMAX galvanization, which offers extra corrosion resistance specifically suited for exterior and treated-wood applications. The 12-gauge steel construction combined with the ZMAX coating makes it a durable choice for demanding outdoor environments.