Installing an entry door requires careful planning, precision, and the right tools to ensure a secure, functional, and energy-efficient result. Whether you’re replacing an old door or installing a new one, following these key tips will help avoid common mistakes and ensure a successful installation.

First, accurate measurements are critical. Before purchasing a door, measure the width and height of the existing door opening (or rough opening for new construction) to ensure the new door fits properly. Measure the width at the top, middle, and bottom of the opening, and the height on the left, right, and center—use the smallest measurements to select the door size. Also, check the squareness of the opening by measuring the diagonal from corner to corner; if the measurements differ by more than ¼ inch, the opening may need to be adjusted (e.g., by shimming or trimming) to ensure the door hangs straight.

Next, gather the necessary tools and materials. Essential tools include a drill, screwdriver (both Phillips and flathead), level (2-foot or longer), tape measure, pencil, chisel, hammer, and shims (thin pieces of wood or plastic used to adjust the door’s position). Materials needed include the door (pre-hung or slab), door frame (if installing a new frame), hinges, screws, weatherstripping, and door sweep. Pre-hung doors (which come with a frame, hinges, and often a threshold) are recommended for beginners, as they simplify the installation process compared to slab doors (which require attaching hinges and fitting into an existing frame).

Proper preparation of the opening is another key step. For replacement projects, remove the old door, frame, and any remaining hardware, and clean the opening of debris. Inspect the rough opening for damage (such as rot or water damage) and repair it before proceeding. For new construction, ensure the rough opening is framed correctly, with studs spaced evenly and the header (top beam) properly supported.

When installing the door, start by placing the pre-hung door in the opening and checking its alignment with a level. Use shims between the frame and the rough opening to adjust the door—shim the top corners first, then the sides, ensuring the door is plumb (vertical) and level (horizontal). Once aligned, secure the frame to the rough opening using long screws (3-4 inches) driven through the frame into the studs, making sure not to over-tighten (which can warp the frame). Install the hinges (if using a slab door) or ensure the pre-hung door’s hinges are secure, then attach the door knob, lock, and deadbolt according to the manufacturer’s instructions.

Finally, add weatherstripping and a door sweep to improve energy efficiency and prevent drafts. Weatherstripping should be installed around the perimeter of the frame, and the door sweep should be attached to the bottom of the door to seal gaps between the door and threshold. Test the door by opening and closing it to ensure it operates smoothly, and check for gaps—if gaps are present, add additional shims or adjust the weatherstripping.

By following these tips, homeowners can ensure their entry door is installed correctly, providing security, functionality, and energy efficiency for years to come. For complex installations (e.g., irregular openings or heavy doors), hiring a professional installer is recommended to ensure optimal results.