Door Too Thin for Knob [Practical Solutions]

Thin doors are commonly used in many portable homes, offering privacy, security, and convenience within limited space. However, sometimes the very feature meant to provide accessibility, such as a doorknob, can present a challenge, especially when the door itself is too thin.

In this article, we’ll explore some easy solutions to deal with installing the doorknob in a thin door by providing a step-by-step guide.

So without further ado…

Let’s get started…

Understanding Standard Door Thickness

Doors come with various thicknesses depending on the space, and the buyer’s requirement.

So the question is…

What is the standard thickness of a door?

The door comes in various thicknesses, typically 1 3/8 inches to 1 3/4 inches. This standard thickness allows for the installation of most door hardware without any issues. However, doors on the thinner end of this spectrum can pose a challenge when it comes to installing a door knob.

When Thin Becomes a Problem

Doors thinner than the standard 1 3/8 inches can make it difficult to install a door knob securely. A door that is too thin may not provide enough material for the screws to grip onto, leading to instability and potential damage to the door over time.

Materials Needed

  1. Doorknob Trim Ring
  2. Drill
  3. Doorknob Extension kit
  4. Screws
  5. Screwdriver
  6. Wood filler (if necessary)

Also Read: Why Put Foil On Door Knob When Alone[Things To Know]

5 Ways to Install a Doorknob in the Thin Door

1. Use Door knob Trim Ring

A doorknob trim ring offers a sleek and functional solution for installing a doorknob on a thin door. Ensure you have all the hardware and tools for the installation.

Steps for the installation

  1. First, keep the door clean then slide the door knob trim ring over the pre-drilled hole in the door. Make sure it is centered and sits flush against the surface of the door.
  2. Insert the doorknob assembly through the hole in the trim ring from one side of the door to the other. Follow the manufacturer’s guide for assembling the knob components.
  3. Once the doorknob assembly is in place, use the provided screws to secure it to the door.
  4. Test the functionality of the doorknob by turning it to ensure that it operates smoothly and securely.
  5. If the doorknob feels loose or if there are any alignment issues, adjust the position of the trim ring and the assembly as needed.
  6. The final step is to make some adjustments if needed and clean up any debris.

2. Use Doorknob Extension Collar

A doorknob extension collar is a set of components designed to address the challenges of installing a standard doorknob on a thin door. This collar typically consists of a sleek cylindrical piece that extends the length of the doorknob, ensuring proper functionality and stability on thinner doors.

Steps for the installation

  1. First, ensure that the door is clean and free from any debris.
  2. Measure the thickness of the door to determine the extent of extension required for the doorknob.
  3. Collect all the necessary hardware components such as doorknob extension collars, screws, screwdrivers, etc.
  4. Slide the doorknob extension collar over the pre-drilled hone in the thin door. Ensure that it is centered and sits flush against the surface of the door.
  5. Insert the doorknob assembly through the hole in the extension collar from one side of the door to the other, also follow the manufacturer’s instructions.
  6. Secure the doorknob assembly by tightening the screws using a screwdriver.
  7. Test the functionality of the doorknob by turning it to ensure smooth operation and security.
  8. Make adjustments accordingly in case of looseness, or alignment issues.

Also Read: Are Mobile Home Door Knobs Different [You Don’t Know This]

Common Challenges During Doorknob Installation on a Thin Door and Their Practical Solutions

Common Challenges During Knob InstallationPractical Solutions
Insufficient Grip StrengthUtilize specialized adhesives or epoxy to reinforce the bond between the doorknob and the door surface. Alternatively, opt for doorknobs with wider bases for enhanced stability.
Inappropriate Screw LengthResolve this issue by either acquiring shorter screws or incorporating spacers to bridge the gap between the screw and the door. Additionally, consider countersinking screws to avoid protrusion.
Alignment DiscrepanciesAddress misalignment by employing shims or wedges during installation. Ensure proper door alignment beforehand and reinforce the door if necessary.
Non-flush Knob PlacementRectify this problem by adding washers or shims behind the doorknob to ensure it sits flush with the door surface. Alternatively, refine the door surface through sanding or planing.


In conclusion, the above-mentioned methods will help you to install a doorknob even in a thin door. By choosing the right hardware and following the installation process diligently, you can ensure smooth operation and peace of mind for years to come.


Q.1 Can I modify a standard door knob kit to fit a thin door?

Ans: While it’s possible with some modifications, it’s generally best to use a door knob kit specifically designed for thin doors to ensure proper fit and stability.

Q.2 Will installing a door knob on a thin door affect its durability?

Ans: Properly installed, a door knob should not significantly affect the durability of a thin door. However, it’s essential to follow manufacturer guidelines and use appropriate hardware.

Q.3 Can I use longer screws if the ones provided are too short?

Ans: It’s not recommended as longer screws may penetrate through the door, causing damage or compromising its integrity.

About The Author


Adam is here, I'm an Editor and writer on guidingpapa. I love to share home improvement tips and new ideas in this blog. I have been doing this from couple of years and I'm very passionate about it.

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