Exterior Door Threshold Buying Guide
Exterior Door Threshold Buying Guide
Exterior door thresholds do more than finish the bottom of your doorway—they help seal out drafts, water, and pests while improving energy efficiency. Choosing the right threshold ensures a more durable, weather-tight, and comfortable entryway year-round.
Know Your Door Type: Inswing vs. Outswing
The first step in selecting a threshold is identifying how your door opens:
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Inswing Doors (open into the home)
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Require thresholds designed to seal tightly against water and wind when closed
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Outswing Doors (open outward)
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Use thresholds shaped to direct rainwater away from the interior
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Matching your threshold to the door swing direction is essential for proper performance and sealing.
Measure for the Right Fit
Width
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Measure the full door opening
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Common sizes: 32", 36", and 72"
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Thresholds are typically sold oversized so they can be trimmed for a precise fit
Length
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Standard lengths: 36" and 72" (uncut)
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“Uncut” means slightly oversized for customization
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Choose a size equal to or larger than your opening, then trim as needed
Height
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Select a height that aligns with your door bottom and flooring
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Avoid creating a tripping hazard
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Adjustable thresholds allow fine-tuning for a tight seal
Typical adjustment range:
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Minimum height: 1 3/8"
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Maximum height: ~1 5/8"
Material & Durability
Choosing the right materials is key for long-term performance:
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Aluminum
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Corrosion-resistant, strong, and low maintenance
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Ideal for most exterior doors
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Composite Base
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Resists moisture and rot
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Especially beneficial in wet or humid climates
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Adjustable Composite Cap
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Helps create a tight seal against the door
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Sealed to protect against moisture and weather exposure
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Weather Protection & Sealing Performance
A quality threshold works together with your door’s weatherstripping or sweep to block out the elements.
Look for:
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Adjustable designs for a tighter seal
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Sloped or beveled profiles to encourage water runoff
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Proper pairing with weatherstripping and door sweeps
In areas with heavy rain or snow, proper installation and sealing are critical for performance.
Using Threshold Extenders
Threshold extenders are a great solution when your doorway is wider than the base threshold.
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Attach to existing thresholds to increase coverage
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Eliminate the need for full replacement
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Available in matching widths (e.g., 4 9/16" or 5 5/8") for proper fit
Example:
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A 5 5/8" threshold with extenders can reach a total width of up to 12"
Final Tip
Taking the time to choose the right threshold—and installing it correctly—will improve your door’s performance, extend its lifespan, and keep your home better protected from the elements.