how to install door trim molding

How to Easily Install Door Trims like a Pro

how to install door trim

how to install door trim

Have you ever seen an awesome door trim design that left you believing that only a professional can make it that sleek?

If you’ve just installed a new door or you’re contemplating on changing your present door trim for reasons related to aesthetics, read this article to the end to learn how to install your door trims like the top professionals.

Until now, you’ve probably believed that you need a knack for door trims before you can professionally install one. A lot of people, who learned the nitty-gritty of the installation, have also thought so at some point.

They eventually found out that it is all a myth because the installation process is not as difficult as it seemed.


Varieties of Door Trims

You must know your trimmings and be able to tell what is right for your door. Choosing the right and most befitting trims will help to make the installation look more professional. The various door trims available on the market are given below.

  • Decorative molding
  • Casing
  • Picture rail
  • Cove
  • Dentil
  • Baseboard and baseboard style
  • Crowns
  • Chair rail
  • Egg and darts

These are the various designs you can comfortably choose from. Go for an ideal design that will match your fashion essence.


Preparing Your Door for Trim Installation

You need to prepare your door, do a proper check, and groom yourself sufficiently before installing door trim.

how to install door trim

Ensure that the gaps between the wall and the door jambs (the door frame to which the door hinges and wherever the latches are used) are closed or bridged. There is no other perfect way to get this done without molding (which is also widely known as casing).

The casing can either be molded or flattened, depending on your choice. The legs and head of the casing can meet at the top of the door in a miter joint or butt joint. 

A miter joint is the end part of two molding pieces (cut at an equal of 45-degrees) that come together to form a square edge shape. While a butt joint is where the square-ends of two moldings meet at 90-degrees to each other.

When you install your door trims, you would want your casing to sit flat and the head joint to properly intersect. To achieve this, the jamb and the face of the wall need to be at plane angles to each other. It is even more significant to pay due attention to this at the top of the door where the joints lie.

You can check this out by holding up a straightedge on the face of the wall. Slightly extend the straightedge until it gets to the jamb. It only needs to barely touch the edge.

If you are going to paint the trim, then you can leave the jamb just as it is. If you want to properly nail the trim in place, first nail it to the jamb, then insert tapered shims into the slight gap between the wall and the back of the casing at the points where you’d nail. The shims will keep the nails from pulling the casing back at any angle.

Once you’re done with the nailing process, you should cautiously cut the shims and casing using a sharp knife. Then, properly caulk the joint with the painter’s caulk for a good installation process.

You can also follow the steps below to prepare for installing a door trim;

  • Collate the proper tools for the installation
  • Make a calculation and rough estimate of the number of trims that you would need to complete the installation. Buy a little extra above your estimate
  • Use a compound miter saw to make precise cuts
  • Get familiar with the various concept involved
  • Ensure that you paint the trims right before installation. This way, you would be saving yourself some time and stress when you begin the installation


Tools for Installing Door Trims

You must use the best tools for optimal results. When it comes to door trims installations, some proposed tools are not efficient. Hence, we have summed up a detailed list of the right tools that will make the entire installation process a lot easier than you’ve read or been told before.

how to install door trim with nail gun

So, here they are:

  • Hammer
  • Cordless trim nailer
  • Crown molding trim installation jig
  • Nail set
  • Knife
  • Miter saw for cutting the door trims to the desirable length
  • Trim measurement tool for the proper installation of a 45-degree corner of joints
  • Stud finder
  • Portable air compressor for powering nailers
  • Shop-vac for cleanup of trim tool dust
  • Jigsaw
  • Block plane
  • Combination square
  • Miter clamps
  • Table saw
  • Belt sander
  • Pencil
  • Materials
  • Prehung door
  • Shims
  • Carpenter’s glue
  • 4d, 6d, and 8d finish nails or 1 ½ in., 2 in., 2 ½ in., and 15-gauge gun nails


Step-by-Step Guide for Installing Your Door Trim

how to install door trim with nail gun

You are ready to begin the installation once you have all the necessary tools. And have braced yourself up with all the things you need to know to keep you going.

The simple DIY methods below will help you to easily install door trims like a pro.


1. Start with Painting Your Trims

    Painting or staining your door trims from the start will save you the stress and time that comes with doing so after installation. It will equally enable you to effectively coat every part of the trim to your satisfaction and give the installation a neat look.

    The painting process is very easy, you just have to apply primer to the wood and paint it with your most preferred color.

    You can, alternatively, use a cloth or rag to clean the wood with a wood conditioner or stain and polyurethane sealer, where you must ensure that each coating dries up before you do the next coating for other trim layers.


    2. Cut the Size of the Trim to Fit Your Door

    This can be achieved when you take a measuring tape to measure the areas around the edge of the door, then proceed to using a miter saw to cut the trim to the size of what you've measured.


    3. Use Wood Glue to Join the Trims

    After getting the measurement, use wood glue to join the end of each door trim together by laying them on the floor. It should give you the exact shape of your door as you do so.


    4. Install the Trim

    This step can be achieved when you drill a small pilot hole inside the top of your trim and insert a screw into the hole.

    how to install door trim

    Go to the opposite corner of the trim and use a finish nail gun to drive a finish nail into it. Then, nail every other part of the trim in place to fit your door perfectly. And that's it! You’ve successfully installed your door trim like a pro!



    Installing a door trim is not as difficult or challenging as it may seem. It can be pretty easy once you can effectively leverage the information we provided in this article. 

    We’ve found out that many methods out there are hardly self-explanatory. That’s why we have simplified things for you by providing this complete and comprehensive guide.

    Reading next

    basement waterproofing
    types of kitchen faucets

    Leave a comment

    This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.