How do you install interior doors?
My time serving in the military didn’t teach me how to use a table saw or how to install an interior door. It taught me precision and focus. I cut on the mark every time because I use a laser just as often as most construction workers use their tape measure. So, how did I learn how to install doors?
My experience hanging doors goes back to my apprenticeship long before completing my military service. I spent most of my apprenticeship hand carving with a chisel instead of using a router because the master carpenter I worked for wanted to teach me to respect each and every cut. Fortunately for my customers, today it means I don’t mess around on the job site.
My installations are quick and precise, with a couple of cheeky dad jokes weaved in between. I always place a high value on my customers' time, so when a returning customer reaches out to me, I treat their project like it’s the only one I’m working on.
I wrote this simple 3-step guide to show you how I installed these 6 swing doors and 2 matching barn doors in just 2 days.
step 1: measure twice
"Measure Twice" serves as just the starting point in your door installation. Once you have your measurements, it's crucial to jot them down ASAP. I always keep a small notepad handy, accompanied by my trusty Milwaukee markers. Depending on the complexity of the cuts, I often sketch what I'm measuring for clarity. These notes, along with clear annotations on various dimensions like material depths and returns, guide me when I return to my table saw to start ripping lumber.
Assuming you're installing interior Pre-Hung doors, the key dimensions you need are the width and height of your door leaf and the overall door opening (frame to frame). In this particular project involving 8 doors, we seized the opportunity to craft custom frames and trim for each door due to a remarkable deal on door slabs. For the average DIY enthusiast, finding "Pre-Hung" doors at a local big-box home improvement store can bypass the need for specialized tools and complex carpentry.
When measuring your doors, start by removing all existing door trim to expose the underlying frame, which is purely decorative. Then, measure from the outside edges of the frame, noting width and height—write these measurements down promptly. Additionally, measure your door leaf. While product measurements online and in-store usually pertain to the door leaf, if possible, inspect the doors in person with your tape measure to compare frame-to-frame measurements. Your measurements should resemble the following:
Master Bedroom: 30” x 80” | 31” x 80 3/4”
Bathroom: 24” x 80” | 34” x 80 5/8”
With your measurements in hand, you're now prepared to begin shopping for doors!
anderson carpentry co.
anderson carpentry co.
anderson carpentry co.
anderson carpentry co.
step 2: fit the frame
There are a few key tools I’ve learned to use over the years that are a necessity for interior door installations. Firstly, ensure you have a good 6-foot level nearby. I find myself reaching for the level at least half the time.
Another essential tool that will save you lots of headaches and ensure you don’t miss the mark with a sudden foot twitch is a set of air shims. In the early days of my carpentry, I relied solely on my steel-toed boots and the strength of my ‘chevrolegs’. It wasn’t until I started installing doors that weighed over 700 pounds and featured overengineered pivots that I learned the immense value of a couple of air wedge bags. Air shims are cheap, reliable, and require no prior experience.
Lastly, if you're installing more than one door, I highly recommend investing in a couple of Door Studs. I use the commercial ones available for $399.00 on Amazon. The amount of energy these beauties have saved me on the job site is significant. In fact, if you're building your own frames and routing out the hinges and strike plate on your door slabs, or installing more than just a few doors, I would almost say it’s a must after using them for a few years now. For the sake of this guide, I’ll assume your doors are pre-hung, so the Door Studs are not a must, just highly recommended.
“Conditions will never be perfect.”
So, you've removed your door trim, unhinged the door leaf, and tore out the old frame. Now that you have a clean, nail-free door opening, it's time to finally start installing your interior door! It's crucial at this stage of your door installation to begin with the hinged side because that's where all the swinging magic happens. If the hinged side is out of alignment, the door will swing open by itself or struggle to open at all. Don’t worry, if you follow these interior door installation instructions carefully, your door will swing without any rubbing, banging, or creaking.
With your door flat on the ground perpendicular to the door opening, raise it so that it stands vertically inside the door opening.
Once you’ve lifted your door into place, carefully unlock it and swing the door leaf wide open so that it sits at 90 degrees perpendicular to the door frame. Keep the door frame nestled in the opening and insert your deflated air shims underneath the door leaf.
Slowly pump the air shims until the door leaf is about 1/4” - 1/2” off the ground.
Grab your level and check if the door leaf is both plumb and square.
Place the level on all sides of the door and adjust your shims as needed until the door leaf is completely level.
At this point, your door frame should stand vertically in the door opening with 1/4” - 1/2” of space all around it, and the door leaf should be at a right angle supporting the frame upright.
Keeping the door frame in place, use your level and place it directly on the hinge side of the frame.
Check both sides of the frame to ensure it's both plumb and square.
Once you're confident, screw a couple of nails into the hinge side of the frame at the bottom and in between the bottom and middle hinges. Fill any spaces between the frame and door opening with some wood shims.
Grab your level again and place it on the top part of the frame (Header). Check all sides to ensure it's both plumb and square.
Now, install the hardware you purchased for your interior door. Follow the instructions it comes with to test if the door is closing and opening properly.
If your door is closing right, you did it! Just keep putting screws in all around your door frame, minding the work you're making for yourself later when you get to step 3. If your door is not closing right, don’t worry. Take your time, going through these 10 steps. It took me more than a decade to get to hang a door on my first try. If you're struggling to get your door closing right, you can appreciate that my apprenticeship was filled with days I worked on a single door.
step 3: trim it out
Trim is where you can easily lose the most money on your interior door installation. While cutting trim is mostly a single measurement, you need to make sure you are precise. Cutting as little as 1/4” can mean you a whole new 8’ board. Take your time and Measure Twice.
When it comes to cutting and nailing in the trim surrounding the door, precision is key. Even though it might seem like a straightforward task, small mistakes can lead to big expenses. Here's how to tackle it:
Firstly, measure your trim carefully. Remember, cutting even a fraction too much can mean wasting a whole board, so Measure Twice! Once you have your measurements, use a miter saw to make precise cuts at the correct angles. Take your time with this step to ensure accuracy.
Next, position the trim around the door frame, ensuring it fits snugly and aligns properly. Use a level to make sure everything is straight and even.
Now, it's time to nail the trim in place. Start by placing nails at regular intervals along the trim, making sure to drive them in flush with the surface. Be careful not to over-nail, as this can split the wood. If necessary, use a nail set to countersink the nails slightly below the surface. Once all the trim is securely in place, fill any nail holes with wood putty and sand the surface smooth. Finally, finish the trim with paint or stain to match the rest of the door and room décor.
By taking your time and being meticulous with your measurements and cuts, you can ensure a professional-looking finish.
