Key Features

Higher Uplift StrengthBuilt for post-to-concrete connections that need more holding power. The CB design increases uplift resistance for wind or seismic loading, which matters when the base connection is doing real structural work.Code-Spaced Bolt HolesBolt hole locations are laid out to meet code-required spacing for optimal capacity. That helps you get the intended performance without fighting bad hole placement in the field.Simpson Strong-Tie CB66 Column BaseThis cast-in-place column base fits nominal 6×6 posts and is made from 7-gauge steel with a galvanized finish. It is a straightforward choice for deck and footing connections where durability and structural value matter.

Overview

The Simpson Strong-Tie CB66 Column Base is a cast-in-place column base made to connect a nominal 6×6 wood post to a concrete footing or foundation. This is a column base designed for post-to-concrete structural connections. Model number CB66. It is a good fit for deck posts and other top-supported columns that need strong bearing, solid uplift resistance, and a clean way to tie wood into concrete.

What sets the CB66 apart is that it is built for higher structural demand than a light-duty post base. Simpson Strong-Tie calls out increased uplift resistance for wind or seismic loading, and the bolt hole locations are set to meet code-required spacing for optimal capacity. In practical terms, that means the connector is doing more than just holding a post in place. It is part of the structural load path, which is exactly what you want when the job is exposed to weather, lateral force, and real service loads.

The CB66 is made from 7-gauge steel and finished in galvanized coating. For this size, that combination gives you a heavy connector with the stiffness needed for column work while adding corrosion resistance for exterior use. Lowes lists the finish as G90 galvanized, while Simpson Strong-Tie lists the CB66 family finish as galvanized. Either way, the main takeaway is that this is a corrosion-resistant steel connector intended for outdoor framing and deck construction, not a thin decorative bracket.

Installation is straightforward, but it is not a slap-it-together part. The base is cast in place or wet set into the concrete with the bottom of the base plate flush to the concrete so the post gets full bearing. Simpson Strong-Tie also notes a minimum 3 inch side cover requirement for full loads on CB models. That matters because this connector only performs as intended when the concrete placement, cover, and bolt installation are done correctly. It is meant for structural work, so layout and embedment are worth taking seriously.

For fastening, the CB66 installs with (2) 5/8 inch diameter machine bolts according to Lowes. The connector is designed around through-bolted post attachment, and Simpson Strong-Tie notes that references to bolts are for structural quality through bolts, not lag screws or carriage bolts. That is a big distinction. If you are choosing a column base for a real load-bearing post, the connection hardware is part of the system, not an afterthought.

This base is intended for wood-to-concrete cast-in-place applications and is commonly used in decks, post-to-footing connections, and other top-supported structures. Simpson Strong-Tie specifically notes that post bases do not provide adequate resistance to prevent members from rotating about the base and are therefore not recommended for non-top-supported installations such as fences or unbraced carports. That is the honest boundary line: the CB66 is a strong structural base for supported columns, but it is not a cure-all for every free-standing post situation.

If you are a deck builder, framing contractor, remodeler, or serious DIYer working on a properly supported post connection, this is the kind of hardware you buy when you want the base connection done right the first time. The CB66 is for jobs where a basic post anchor is not enough, and where post size, concrete interface, and uplift capacity all matter.

Built for Real Structural Post Connections

This connector is meant for structural post work, not light trim carpentry. The cast-in-place layout gives the post full bearing at the base while tying the column directly into the footing.

• Designed for wood-to-concrete cast-in-place applications
• Simpson Strong-Tie specifies minimum side cover requirements for full loads on CB models

Hole Layout That Matches the Job

The hole spacing is one of the details that separates structural hardware from generic brackets. Here, the bolt pattern is laid out for code-required spacing, which helps the connection deliver the capacity it was designed for.

• Installs with (2) 5/8 inch diameter machine bolts
• Bolt hole locations are designed for optimal structural capacity

Key Specifications

Compatibility

Post SizeFits nominal 6 x 6 wood columns.Bolt HardwareDesigned to install with (2) 5/8 inch diameter machine bolts.Base ApplicationMade for wood-to-concrete cast-in-place or wet-set installations where the base plate sits flush with the concrete.

Built For

Deck BuildingPost-to-Footing ConnectionsConstructionGeneral ContractingRemodelingCarpentryExterior Structural Framing

Pro Tip

Set the CB66 so the bottom plate finishes flush with the concrete and verify your side cover before the pour. That little layout check is a lot easier now than explaining later why the post base landed too close to the footing edge.

Tool Nut’s Take

Tool Nut’s Take

Simpson Strong-Tie CB66 Column Base for serious post work

If your 6×6 post connection needs real structural muscle at the footing, this is the kind of base you spec instead of hoping a lighter bracket will be enough.

• Who it’s for: Deck builders, framers, remodelers, and anyone tying a nominal 6×6 post into concrete on a top-supported structure.
• Why it stands out: 7-gauge steel, galvanized corrosion resistance, and a bolt layout designed around code-required spacing and higher uplift demand.
• Worth knowing: This is a cast-in-place column base, so placement matters. It is also not recommended for non-top-supported installations like fences or unbraced carports.

Common Questions

• What is the CB66 used for? It is used to connect a nominal 6 x 6 wood post to a concrete footing or foundation in cast-in-place applications.
• Is the CB66 adjustable? No. Lowes lists this column base as non-adjustable.
• What fasteners does it use at the post? Lowes specifies installation with (2) 5/8 inch diameter machine bolts.
• Can this be used for a free-standing fence post or unbraced carport post? No. Simpson Strong-Tie states that post bases are not recommended for non-top-supported installations because they do not provide adequate resistance to prevent rotation about the base.