Mastering Plank Wall Corners: A DIY Guide to Flawless Finishes

Welcome back, fellow DIY enthusiasts! You might recall a few years ago when I embarked on a significant home improvement journey, transforming my spacious hallway with a striking barn door installation and a beautiful tongue-and-groove plank wall. It was a project that brought immense character to the space, but like many ambitious DIY endeavors, it left a lingering question mark: those notoriously “ugly corners.” Many of you asked about them, and I promised to address them in due time. Well, that time has finally arrived!

With my new office space now framed in, the adjacent plank wall needs a proper finish, making this the perfect opportunity to tackle those neglected corners. What initially seemed like a minor oversight has become a prominent feature that detracts from the overall elegance of the plank wall. Achieving a polished, professional look in home renovation projects often comes down to the details, and unfinished corners are certainly a detail that demands attention. My goal is to ensure the entire area, particularly where the planking meets other wall surfaces or transitions, is visually appealing and structurally sound.

The Persistent Plank Wall Corner Problem

From the outset, I envisioned using standard corner trim to tidy up the raw edges of my DIY plank wall. It seemed like the most straightforward solution. However, as often happens in real-world DIY, theoretical solutions don’t always translate perfectly. The planks I used are a substantial 3/4 inch thick, which immediately posed a challenge for conventional corner molding. Standard decorative trim pieces are typically designed for drywall corners or thinner wall coverings, not for accommodating the combined thickness of two 3/4-inch planks meeting at an angle, plus the underlying wall structure. This means any off-the-shelf corner trim would have to be unusually large, practically “gigantic,” to effectively cover both sides of the planking and bridge the empty space of the corner itself.

The Unveiling of the Corner Trim Conundrum

My initial attempt involved purchasing some readily available stock corner trim, optimistically believing I could simply install it and declare the job done. Unfortunately, the standard 3/4 inch by 3/4 inch dimensions of this trim proved inadequate. While it could cover one side of the plank perfectly, it left a significant, unsightly gap on the other side, exposing the raw edge of the adjacent plank or the unfinished wall behind it. This scenario is a common pitfall for many DIYers who try to adapt standard materials to custom projects. The discrepancy was too prominent to ignore, shattering my hopes for a quick fix.

Following this realization, my thoughts turned to creating custom corner trim that would perfectly match the thickness and aesthetic of the plank wall. The idea was to mill or construct a piece that would provide a clean, continuous finish, seamlessly wrapping around the corner. While this remains an excellent solution for bespoke projects, time constraints and the demands of other ongoing renovations meant this idea never materialized. Consequently, the corners of my beautiful plank wall have remained in this unfinished state for far too long, serving as a constant reminder of a project yet to be fully completed. The uneven ends and exposed edges have patiently awaited their transformation, diminishing the overall impact of the otherwise charming planking.

Rethinking the Design: A Strategic Shift

As I finally committed to tackling these corners, I also took the opportunity to re-evaluate the design of the entire hallway. After careful consideration, I decided against extending the horizontal planks onto a small side wall, realizing that a cleaner, more defined transition would enhance the overall aesthetic. This decision meant carefully removing the existing planks from that section. The removal process was meticulous, requiring me to extract close to “100 nails” that had securely fastened the planks in place. This painstaking step was absolutely crucial because I needed to ensure a perfectly clean and nail-free surface before making any cuts to the remaining plank wall.

The primary reason for pulling every single nail was to safeguard my saw blade. Hitting a hidden nail with a high-speed saw blade can not only damage the blade irreparably but also pose a significant safety risk, leading to dangerous kickback or flying debris. Moreover, a clean cut, especially a vertical one that will be visible, demands a smooth path without any obstructions. The challenge was to achieve a perfectly straight edge, which is notoriously tricky when cutting vertically on an already installed surface. Without a reliable guide, the likelihood of an uneven or wavy cut increases dramatically, compromising the professional finish I was aiming for. This preparatory work, though tedious, lays the groundwork for precision and safety in the subsequent cutting phase.

Precision Cutting: Leveraging an Unexpected Guide

As I pondered how to achieve that elusive straight vertical cut on the plank wall, a stroke of pure, unexpected luck presented itself. I discovered that the existing door casing was positioned at “EXACTLY the perfect distance” from the end of the wall to serve as an impromptu, yet ideal, guide for my circular saw. This kind of serendipitous alignment, where an existing architectural feature perfectly serves a new purpose, is something that, in my experience, “NEVER happens” in DIY projects—but it did! While it wasn’t absolutely flawless, it was “almost perfect and close enough for me to cover with my corner piece.” This happy coincidence saved me considerable time and effort that would otherwise have been spent setting up a custom straightedge guide.

Utilizing the door casing as a natural guide, I carefully ran my circular saw along its edge, making a precise cut. The power and speed of a circular saw make it ideal for quickly and efficiently trimming long, straight lines. The slight imperfections or “tear out” that might occur during such a cut, especially on wood planking, were of no concern. Why? Because these newly trimmed edges would eventually be covered by the custom corner trim piece I plan to install. This foresight allowed me to focus on getting the cut as straight as possible, knowing that any minor cosmetic blemishes would be concealed. This was truly “perfect luck for an ‘in place’, perfectly placed circular saw guide!” It’s these small victories that make the challenges of DIY so rewarding, allowing for efficient progress without compromising the final aesthetic. However, the circular saw couldn’t complete the entire cut due to its size and reach limitations, particularly in the tighter, more confined sections of the wall.

The Versatile Hero: Mastering the Oscillating Multi-Tool

When the circular saw reached its limit, unable to extend its cut into the tighter corners or complete the flush cut against the floor or ceiling, it was time to introduce a different kind of precision. This is where my trusty oscillating multi-tool stepped in to save the day. This incredibly versatile tool is a DIYer’s best friend for situations demanding intricate cuts, flush trimming, or working in confined spaces where larger saws simply cannot go. Its unique oscillating action allows for precise, controlled cuts without the rotational force that can cause kickback in other tools, making it particularly safe for delicate work.

For this project, the oscillating multi-tool was essential for making the final, flush cuts that the circular saw couldn’t manage. Equipped with a sharp flush-cut blade, it allowed me to trim the plank edges perfectly even with the adjacent wall or floor, ensuring a seamless transition for the upcoming corner trim. This tool excels at tasks like undercutting door jambs, trimming excess material, and, as demonstrated here, creating perfectly straight edges in awkward spots. Its ability to plunge cut and make precise cuts in various materials (wood, metal, drywall, grout) makes it indispensable for a wide array of home renovation tasks. If you’re not familiar with the capabilities of this amazing tool, or simply want to see it in action, I took the perfect opportunity to record a quick video demonstrating its use for flush trimming:

This video provides a visual guide to how effortlessly the oscillating multi-tool handles these precise cuts, truly showcasing its value in achieving a professional finish where other tools fall short. It’s a game-changer for anyone looking to elevate their DIY skills and tackle more complex projects with confidence.

A Foundation for Flawless Finishing

With the cutting complete, the transformation is already quite dramatic. The once uneven and unsightly edges of the plank wall are now perfectly straight and clean. Although the ends still require the application of the custom corner trim to truly complete the look, the most challenging part of preparing the surface is now behind me. The mess of sawdust is a testament to the hard work, but also a visual representation of progress towards a cleaner, more refined aesthetic.

The difference is undeniable. What was once an overlooked, “ugly” corner now presents a crisp, intentional edge, laying the perfect foundation for the final trim installation. This meticulous preparation is key to ensuring that the finished product looks cohesive and professionally done. Don’t you agree? This journey from problem identification to strategic execution, leveraging the right tools and a little bit of luck, truly highlights the essence of DIY. The satisfaction of seeing these clean lines after grappling with the corner dilemma for so long is immense. Stay tuned for the next phase where we’ll explore options for creating and installing that perfect custom corner trim, finally bringing this plank wall project to a beautifully polished conclusion. Your home renovation journey can be just as rewarding!