How to Measure an Opening for a Steel Door

A typical steel door opening.

When replacing exterior doors with new steel doors, the existing framing needs to be looked at. The steel door is heavier and more secure than a traditional wood door. A new steel door can be installed in place of most doors that are at least 2 feet, 8 inches wide. Other sizes will be a custom order. The do-it-yourselfer can measure the opening for a steel door with just a tape measure, paper, pencil and a few hand tools.

Things You'll Need

• Utility knife
• Tape measure
• Paper
• Pencil
• Trim pry bar
• Hammer
• Trim pliers

Instructions

1. Remove the interior wood trim from around the existing door carefully. The trim can be put back until the new steel door is installed.

2. Cut the painter's caulk from between the wall and the door trim. A sharp utility knife works best. This will keep the caulk from pulling the paint off of the wall when the trim is removed.

3. Pry the trim away carefully from the door using a trim pry bar. The trim pry bar has a narrow and wide end that you can easily tap between the door jamb and the trim. Use a hammer for this.

4. Pull the finish nails through the back of the trim using a pair of trim pliers. This will leave a small hole in the face of the trim that can be nailed through to reinstall the trim.

5. Measure the width of the rough opening. The rough opening is the space between the 2-by-4 wall studs on each side of the existing door.

6. Measure from the floor up to the wood header above the door frame. The header is made up of two 2- by 12-inch pieces of lumber, with a piece of plywood sandwiched between them. This is the height of the rough opening.

7. Measure the depth of the door jamb. The door jamb is the piece of door framing that the interior and exterior trim is attached to. The typical door jambs a 4 9/16 or 6 9/16-inch wide. The door supplier will need all of these dimensions when he orders the new steel door.

References

• Larson Doors: How to Buy-Measuring
• Steel Storm Doors: Door Measuring
• My Home Improvement: Door Measuring

Resources

• Read this Article in Spanish