Modular Vinyl Post Trim Sets from Superior Outdoor Products - Choose Your Size and Color

Product Description

Superior Outdoor Products Modular Vinyl Post Trim Sets – Adjustable 3"–6-1/2", 4" & 5"

• 4-piece modular design — Each Modular Post Trim Set includes four interlocking pieces that assemble around the post, so you don’t have to slide the trim down from the top.
• Ideal for existing rail installs — Perfect for finishing posts that already have railing brackets attached, helping you avoid removing and re-mounting your rail hardware.
• Adjustable and fixed-size options — Choose an adjustable 3"–6-1/2" set for multiple post sizes or dedicated 4" and 5" Modular Trim Sets for a snug, tailored fit.
• Engineered to match Superior posts — The 3"–6-1/2" set uses a square corner radius that works across many post profiles, while the 5" Modular Trim matches the corner radius of 5" turned posts for a seamless look.
• Color-matched post accents — Offered in standard Superior vinyl colors (per the post cap & trim selector, Modular trim is not available in Black), so your trim can coordinate with posts and railings.
• Durable, USA-made vinyl — Manufactured in the USA from high-quality virgin PVC for long-term outdoor performance and low maintenance (per Superior’s product family practices).

The Superior Outdoor Products Modular Vinyl Post Trim Sets give you a flexible, jobsite-friendly way to finish vinyl post bases—especially when the railing is already installed. Instead of sliding a one-piece trim ring over the top of the post, each modular set snaps together around the post at the base, making it an excellent solution for retrofit or remodel work. Choose the adjustable 3"–6-1/2" Modular Trim Set when you’re working with multiple post sizes, or select dedicated 4" and 5" Modular Trim Sets for a more precise fit and a smooth transition from post to deck, porch, or stair landing.

Why Choose This Modular Post Trim

• Retrofit-friendly design — Four-piece modular construction simplifies adding base trim to posts after railings and brackets are already in place.
• One trim for many post sizes — The 3"–6-1/2" adjustable set is ideal for projects using different vinyl or wrapped post sizes, reducing the number of unique trim SKUs needed.
• Tailored look for 5" turned posts — The 5" Modular Trim is designed to match the corner radius of 5" turned posts, giving those premium posts a properly fitted base.
• Clean, finished base detail — Helps conceal cut edges, shims, and minor gaps where posts meet the finished surface for a more professional appearance.
• Low-maintenance finish — Vinyl trim won’t rot, peel, or flake like painted wood skirts and cleans up easily with mild soap and water.

Specifications

Installation

Confirm whether you need an adjustable 3"–6-1/2", 4", or 5" Modular Trim Set based on your post sleeve size and profile. With railings and brackets already installed, separate the four trim pieces, position them around the post at the base, and snap or fit them together per Superior’s installation guidance. Ensure the trim sits flat against the deck, porch, or stair surface and that the seams are tight for a clean finished look. Repeat for each line, corner, and stair post, keeping post heights consistent so the trim line appears level across the project.

Buying Guide

• Use modular trim for “already built” posts — If your railing is in place, Modular trim lets you add base skirts without removing brackets or rails.
• Choose adjustable vs. fixed size — Select the 3"–6-1/2" adjustable set when working with multiple post sizes; use 4" or 5" sets when you want a dedicated, snug fit for one post size.
• Match the corner radius to the post style — For 5" turned posts, use the 5" Modular Trim so the corner radius lines up correctly with the post profile.
• Plan one set per post — Count all posts, including stairs, corners, mid-spans, and entry posts, so you order enough sets for the entire layout.
• Coordinate with other trim styles if needed — Use Modular trim where retrofit flexibility is important and pair with Classic or Plain trim on new, slide-over installations if you want varied looks.

Frequently Asked Questions

What is Modular vinyl post trim?

Modular vinyl post trim is a four-piece base trim set that assembles around a post, allowing you to finish the base without sliding a one-piece skirt down over the top.

When should I choose Modular trim instead of Classic or Plain trim?

Modular trim is ideal when the railing is already installed or when you’re working with posts that are difficult to slide a one-piece trim over, such as posts with brackets, wraps, or varied sizes.

What sizes are available for Superior Modular Post Trim Sets?

Superior offers Modular trim sets in an adjustable 3"–6-1/2" size for multiple post dimensions, as well as dedicated 4" and 5" sizes for specific post sleeves.

Does Modular trim work with 5" turned posts?

Yes. The 5" Modular Trim is designed so its corner radius matches the corner radius of 5" turned posts for a more seamless fit at the base.

Is Modular trim structural?

No. Modular post trim is non-structural; it is intended as a decorative base piece to conceal gaps and cut edges where posts meet the surface.

Does the Modular trim include posts or mounting hardware?

No. Each Modular Post Trim Set includes only the four trim pieces. Vinyl posts, post mounts, caps, and other hardware are sold separately.

Comparison

Need help choosing between adjustable and fixed-size Modular trim, or mixing Modular with Plain or Classic trims on the same project? Please contact us.