Installing a new storm door can greatly improve your home’s weather protection, security, and curb appeal. But in order to get the perfect fit, you need to measure your storm door opening accurately and precisely. In this complete guide, we’ll cover all the key steps for measuring storm door openings correctly so you can install your new door like a pro.
Before You Measure
Before grabbing your tape measure, there are a few important things to do first to set yourself up for success.
Gather the Right Measuring Tools
Having the proper tools on hand will make taking measurements a breeze. Here are the must-have items:
- Steel tape measure. Look for one at least 25 feet long so you can take vertical measurements.
- Pencil and paper or notepad for writing down measurements.
- 4-foot level. This helps confirm your opening is plumb and square.
- Spreading caliper (optional). Makes it easy to measure inside width at top, middle, and bottom.
Avoid cloth measuring tapes, as they can stretch and provide inaccurate readings. Stick with a quality steel tape for durability and precision.
Use Proper Safety Gear
Safety should always come first when working on a home improvement project. Here are some tips to stay safe:
- Use a sturdy, non-slip ladder to reach the top of the door
- Have someone assist you and hold the ladder steady
- Work during daylight hours so you have good visibility
- Clear any debris or obstructions from around the door
- Wear gloves to avoid sharp edges around the door frame
Rushing causes mistakes, so take your time and follow safety protocols. And don’t work in bad weather, as rain or wind can make conditions hazardous.
Measuring the Width
When sizing a storm door, the width is one of the most critical measurements to get right. Here’s how to measure it correctly:
Take Measurements at Multiple Points
Don’t just measure the width at one spot. Use your tape measure to measure the width at the:
- Top of the opening
- Middle of the opening
- Bottom of the opening
This gives you an accurate reading that accounts for any inconsistencies across the opening. You may find the width varies by a fraction of an inch in different spots.
Note the Narrowest Width
Once you’ve measured the width at the top, middle, and bottom, note down the smallest, narrowest measurement. This narrowest point is the width you’ll need to order your storm door at. A wider door simply won’t fit in the opening.
For example, if you measure 34 inches at the top, 33.75 inches in the middle, and 33.5 inches at the bottom, you’ll want a door that’s 33.5 inches wide.
Account for Clearance with the Door Jambs
Don’t cut it too close when sizing the width. Leave at least 1/2 inch, up to 1 inch clearance between the door and the jambs for operation. This extra room allows the storm door to swing open without rubbing or catching on the jambs.
So in our example above, you’d want to order a storm door around 32.5 inches wide to allow that extra clearance.
Measuring the Height
In addition to the width, an accurate height measurement is crucial for proper storm door sizing and installation. Follow these steps:
Take Measurements at Three Points
As with the width, avoid taking just one height measurement. Use your tape measure to measure the height:
- On the left side of the opening
- In the center of the opening
- On the right side of the opening
This gives you the full picture of the opening size, accounting for any unevenness across the top.
Use the Shortest Measurement
Once you’ve measured the left, center, and right sides, note down the shortest height measurement. For storm doors, you always want to size based on the shortest height to ensure it will fit.
For example, if you measure 80 inches on the left, 79.75 inches in the center, and 80 inches on the right, you’ll use the 79.75 inch center measurement.
Factor in the Door Threshold
Don’t forget to account for the door sill or threshold at the bottom of the opening. This will take up around 1/2 to 3/4 inches of height.
So for our 79.75 inch measurement, we’d subtract 1/2 inch and order a storm door 79 1/4 inches tall.
Double Checking Measurements
Measuring storm door openings takes precision and diligence. Don’t assume you got it right the first time. Take these steps to double check:
Re-Measure for Accuracy
It’s easy to make small mistakes when measuring the first time. Go back and re-measure both the width and height a second time. This verifies your numbers and catches any errors.
Have Someone Else Validate
For maximum assurance, have a second person measure the opening using their own tape. This provides a second set of eyes and hands to confirm your measurements.
Reference Measure the Old Door
If possible, remove the old storm door and measure its actual width and height. Compare it to your opening measurements as another check. Look for any major discrepancies or differences between the old door and new measurements.
Ordering the Right Size
Once you’ve double checked all your measurements, it’s time to order the new storm door. Use these tips to get the size right:
Account for Manufacturing Variations
Most storm door sizes have a manufacturing tolerance or variance of around 1/4 inch. Compare your measurements against the manufacturer’s listed sizes and order slightly smaller if needed.
Consider Custom Sizing
For openings that are an odd size or shape, ordering a custom-sized storm door is wise. Provide your precise measurements to the manufacturer to get an accurate custom fit.
Size Down if the Opening is Unstable
If your home is older or settling unevenly, the opening size may change slightly over time. Size down the door slightly to prevent future fit issues in an unstable opening.
Getting accurate storm door measurements is crucial for hassle-free installation and performance. Follow this guide to measure properly:
- Use the right tools and safety gear
- Measure width at multiple points, noting the narrowest
- Measure height at left, center and right, using the shortest
- Double check all measurements for accuracy
- Reference your old door size if possible
- Order a size smaller if needed to ensure fit
Taking the time to measure correctly will ensure your new storm door fits the opening perfectly and provides protection for years to come. So grab your tape measure and start measuring like an expert!
Measuring for a Storm Door with Unique Shape:
Some homes may have uniquely shaped doors, such as arched or curved doors. In such cases, measuring for a storm door can be a bit more complicated. In addition to measuring the width and height, you’ll need to measure the radius of the arch or curve. Use a flexible tape measure to get accurate measurements, and consider hiring a professional for the job to ensure a proper fit.
Measuring for a Storm Door with Multiple Panels:
Some storm doors come with multiple glass or screen panels, which can add to their overall size and weight. In this case, you’ll need to measure the distance between each panel, as well as the overall width and height of the door. This will ensure that the storm door fits properly and doesn’t obstruct any nearby obstacles, such as windows or exterior decor.
Measuring for a Storm Door with a Pet Door:
If you have a pet door installed in your storm door, you’ll need to measure around it to ensure that the new storm door will fit properly. Measure the distance between the edges of the pet door, and make sure the flap has clearance to open and close. Consider getting a new storm door with a pre-cut opening for the pet door to save hassle.