3.5" to 6.5" Adjustable 4 piece post trim base by RDI

$9.99 - $11.99
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(18 reviews) Write a Review
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Adjustable 4-Piece Post Trim Base by RDI

Trim comes in 4-pieces that slide into one another creating sizes between 3-1/2" to 6-1/2"

For use when sliding over an existing post is NOT an option!

Can also be used as a standard base post trim.

If you’re working on a deck or porch project and are looking to evoke the timelessness of beveled wood details, consider adjustable four piece post trim by RDI as an equally alluring solution for a fraction of the hassle and cost. Not only is this adjustable deck post base incredibly easy to work with, but it is just as attractive as any wood option. The flexibility this adjustable four piece deck post base offers makes it an appealing addition to any railing or deck, as long as your posts range in size anywhere from 3.5 to 6.5. Available in White, Dune, and Earth, these post bases are sure to add polish to any job, whether you are a contractor or a homeowner making a few improvements.

Crafted using weather-resistant vinyl, RDI’s adjustable deck post base can withstand the elements and is incredibly low-maintenance. Plus, RDI offers a lifetime warranty on all of its products, so you never have to worry. As a bonus, Deck Expressions offers free domestic shipping on all orders over $99.99, so you can afford to stock up on everything you need to finish your project and make your home look great.


  • Post trim adjusts to fit posts from 3-1/2" to 6-1/2"
  • Great for Post Sleeves 
  • Works on any post size from 3.5" to 6.5"
  • Comes in 4 - pieces


  • White
  • Dune
  • Earth

final-line-color-white.png final-line-color-earth.png final-line-color-dune.png

Width - 1-1/2"

Height - 1- 5/8"


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  • 5
    Adjustable post trim

    Posted by Jessica C on Jun 18 2020

    These finish off our Farmer’s Porch post wraps perfectly! Very easy to install and make a nice finishing touch!

  • 4
    Nice finish

    Posted by Chuck Skellen on Jun 12 2020

    They made the new post wraps look great.

  • 5
    Great product

    Posted by Andy Munoz on Jun 5 2020

    Love the style, the quality of the material, and the price.

  • 5

    Posted by Matthew Harris on May 7 2020

    These adjustable trim pieces are super easy to install, and they look great after installation.

  • 4
    One of them came broken

    Posted by John Zaccone on Jan 25 2020

    As it turned out, I didn't need them, It is a great concept. I did test the one that wasn't broken and it would have been a good fit. I understand that things can happen in shipping. I didn't bother to contact the seller so I am not going to give a bad review. But maybe start wrapping them in bubble wrap in the future.

  • 5
    Adjustable base

    Posted by ralphel Elliott on Oct 22 2019

    Has premarked lines to cut by inside goes together very well. When using these trim base pieces if you have a post that’s twisted at the bottom you’re able to trim these pieces to make it hard to tell because it makes it look square to the porch or sidewalk great product.

  • 5

    Posted by Betty Kaufman on Sep 2 2019

    We haven’t finished the job yet, I’m sure they will look good with the sleeves we bought before.

  • 5
    Skirts for 6 x 6 posts

    Posted by Jerry ealling on Aug 30 2019

    Awesome product to finish off posts

  • 5
    Post base

    Posted by lisa on Aug 16 2019

    These post bases really set off the wraps. Simple to put on, just have to have a way of trimming them to make them fit. Very nice, sturdy product.

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