The Simpson BC4 Post Cap is a dual-purpose post cap and base engineered by Simpson to deliver a positive, mechanical connection between a 4x post and a wood deck or patio cover. Constructed from 18-gauge steel with a G90 zinc galvanized coating, this connector provides a stronger, more reliable alternative to angled nailing or screw fastening alone - making it a dependable solution for light-duty, top-supported structural applications where post-splitting and end-grain nailing are concerns.

Key Features

• Positive post-to-deck connection - creates a secure mechanical attachment that keeps the post firmly anchored to the wood structure, reducing movement and long-term instability
• Stronger than angled nailing or screw fastening - provides greater load transfer and connection integrity compared to traditional field-fastening methods, giving builders added confidence in the joint
• Reduces post splitting and eliminates end-grain nailing - the bracket-style design distributes fastener loads away from vulnerable wood grain, helping preserve post integrity over time
• 18-gauge steel construction - delivers the structural rigidity needed for light-duty post cap and base applications without unnecessary bulk
• G90 zinc galvanized coating - provides extra corrosion resistance, making this cap well suited for outdoor environments such as decks and patio covers where moisture exposure is ongoing
• Sized for nominal 4x posts - designed specifically to fit standard 4x lumber, ensuring a consistent, properly fitted connection right out of the box
• Top-supported installations only - engineered for applications like decks and patio covers where the post is supported from above; not intended for fences or unbraced carports, so buyers can match it to the right project from the start

Why This Product

• A mechanically stronger connection than traditional fastening - rather than relying solely on angled nails or screws driven into end grain, the BC4 creates a bracketed connection that distributes load more effectively and reduces the risk of post splitting over time
• Built for outdoor durability - the G90 zinc galvanized finish is specifically chosen to resist corrosion in exposed conditions, making this post cap a practical long-term choice for deck framing and covered patio structures subject to weather and moisture
• Dual-purpose versatility in a single connector - the BC series design functions as both a post cap and a post base for light-duty applications, offering flexibility when planning deck or patio cover framing details
• American-made quality from a trusted structural connector brand - Simpson produces this connector domestically and specifies compatible fasteners, so installers can build a complete, properly matched connection without guesswork

Specifications

• MPN: BC4
• Member Size: 4x
• Width 1: 3-9/16 in.
• Width 2: 3-9/16 in.
• Length 1: 2-7/8 in.
• Length 2: 2-7/8 in.
• Height 1: 3 in.
• Height 2: 3 in.
• Gauge: 18
• Coating: Zinc Galvanized, G90
• Finish: Zinc Galvanized, G90
• Install With: 16d common nails or #10 x 1-1/2 in. Strong-Drive SD screws (sold separately)
• Country of Origin: United States

Downloads and Resources

• View Spec Sheet

Frequently Asked Questions

What is the BC4 post cap used for?

The BC4 is a dual-purpose post cap and base designed for light-duty applications such as connecting a 4x post to a wood deck or patio cover. It provides a positive mechanical connection that is stronger than angled nailing or screw fastening.

What fasteners should be used to install the BC4?

The BC4 should be installed with 16d common nails or #10 x 1-1/2 in. Strong-Drive SD screws for a proper and secure installation.

Is the BC4 suitable for use in outdoor or high-moisture environments?

Yes. The BC4 features a G90 zinc galvanized coating, which provides extra corrosion resistance, making it well suited for outdoor applications such as decks and patio covers where exposure to moisture is a concern.

Can the BC4 be used for fences or unbraced carports?

No. The BC4 is not recommended for non top-supported installations such as fences or unbraced carports. It is intended for top-supported light-duty applications only.