When learning how to install an exterior door, you'll find there are a few more steps and tools needed to get the job done than when installing an interior door. Nonetheless, this is absolutely a DIY job you can do with the right equipment, hardware, door, frame, and a can-do attitude!

To begin the process, you will have to carefully remove the old door: the longer it’s been there, the more cautious you’ll need to be to ensure you don’t do damage to your home’s exterior. However, this is a simple task — simply remove the door from the hinges so you have an open space. Next, you’ll need a hammer and a flathead screwdriver: use the hammer to tap the screwdriver to remove trim, casing, moulding, and any portion of the old doorframe that may not have gone easily when the old frame was detached. When you’re done, what you should have is a “blank canvas” — a clean, fresh opening in the wall where you can easily install a pre-hung door within a frame you’ve chosen from one of our tens of thousands of exterior entryways at ETO Doors.

How to Install an Exterior Door with Frame: About Opening Direction and “Rough Opening”


Before you get too far into the process and realize you don’t have a choice, make a conscious decision about whether you want the door to open inward or outward, and whether you’d like the handle on the right or left hand side. After you’ve chosen, address the dimensions of the installation space by measuring anything about it you can: its height, its width, and how deep it is. The totality of these measurements is called the "rough opening," and knowing these dimensions will determine which exterior door you can choose to fit into that area. As a general rule, when learning how to install an exterior door, memorize this fact: the new exterior entryway needs to be one-half inch shorter, and three-quarters of an inch thinner than the rough opening.

Critical Aspects of How to Install an Exterior Door: Dry Fitting to Finishing Assembly


When you have your new exterior door sitting there, ready to go, before you get out the nails, glue, paint, or any tools, you must do what’s called a “dry fit”: this is when you take the pre-hung door and frame (or just door if the frame is already installed) and literally pick it up, and attempt to fit it into the rough opening. This will give you the insight you need in the event the door is too big, too small, and so on. If the door is too big, there’s not much you can do, unless you’re in the process of a home build or full remodel that gives you the leeway to edit the rough opening to fit the larger door.

If the door is too small, you may wish to return it for the next size up if it really looks very small from the street, curb, or the edge of the lawn, as examples — but these are all completely subjective — not everyone wants a huge door. So, if you opt to keep the small door, you’ll need to work with the rough opening to accommodate the door. This could mean spackling, adding sheetrock, or just a small amount of epoxy filler if the size difference is not that much.

Part of the dry fit should include ensuring the door will clear the floor when opening and closing before affixing the pre-hung fixture into the wall. And finally, before making the big move of installing your exterior door, check what's called the “sub sill” — this is a “window sill for doors,” if you will, and is what sits atop the ground sill, another type of foundation. To make sure the installation of your door is not lopsided or crooked, during the dry fit, you should notice if there is more open-air space on one side or the other of the ground sill. For installation, this is no big deal: to keep the doorway from being crooked, simply use shims or wooden wedges to repair the issue, and measure with a laser level to be sure these additions are doing their job before finalizing the installation.

Once all these adjustments have been made, raise the doorframe into the rough opening, and use shims as tools to situate the door into place. One caveat: on the side of the entryway where the lock will be, do not place any shims in the center — add all of them at the top and base on that side of the door. Next, insert the permanent shims between the frame and studs, leave them there, and you’re ready to start driving in some screws! Ensure that you drill screws through both the hinges of the door and the shims you have just placed between the frame and studs.

Insulation, Trim, and Wrapping Things Up!


Utilize your manufacturer's manual to ensure you have not skipped any steps unique to this model or their doors in general. Beyond this, after all screws have been driven in and you've proven the door within the frame swishes back and forth unencumbered, you're almost done. The last thing you need to know to complete your education on how to install an exterior door is to spray insulation foam into any nooks and crannies between the frame and the perimeter of the rough space — this will create the best possible insulation. And finally, affix your beautiful trim — you're done!