Door Gap Fix: Install an Extender in 5 Easy Steps!

That annoying breeze snaking its way under your exterior door isn’t just a nuisance; it’s a drain on your wallet and a threat to your home’s comfort. Door gaps are a common problem, especially in older homes, and they can significantly impact energy efficiency.

The Problem: Door Gaps Under Exterior Doors

A door gap under your exterior door is essentially an invitation for the outside elements to come inside. Cold drafts in winter, sweltering heat in summer, rain, snow, and even unwanted pests can easily slip through.

This forces your heating and cooling systems to work harder, leading to higher energy bills. More than that, it creates uncomfortable temperature fluctuations within your home.

The Benefits of Fixing the Gap

Addressing a door gap offers a multitude of benefits, far beyond simply eliminating a draft.

Improved energy efficiency is a primary advantage. By sealing the gap, you reduce heat loss in winter and heat gain in summer, lowering your energy consumption and saving money.

Enhanced weatherproofing protects your home from the elements, preventing water damage and mold growth.

And finally, a properly sealed door creates a more comfortable and consistent indoor environment, free from drafts and temperature fluctuations.

The Solution: Exterior Door Threshold Extender

The good news is that fixing a door gap is often a straightforward DIY project. An exterior door threshold extender is a simple, yet effective solution for sealing the gap between the bottom of your door and the threshold.

It adds height to your existing threshold. Effectively creating a tighter seal against the door.

Simple Installation: A DIY Project for Most Homeowners

Installing a threshold extender is a project that most homeowners can tackle with basic tools and a bit of patience. The installation process is relatively simple, typically involving measuring, cutting, and securing the extender to the existing threshold. With a little effort, you can say goodbye to drafts and hello to savings.

Understanding the Need for an Extender

As we’ve seen, a door gap can be a real problem. But what exactly causes these gaps to form, and why is it so important to address them with a solution like a threshold extender?

The Anatomy of a Door Gap: How They Form

Door gaps aren’t typically present when a door is first installed. They develop over time due to several factors:

• Settling Foundation: Over time, houses settle. This can cause the door frame to shift, creating gaps where none existed before.

• Warping Doors: Changes in humidity and temperature can cause wooden doors to warp or bow.

  This distortion often leads to uneven gaps along the bottom edge.

• Wear and Tear: The threshold itself can wear down over time due to foot traffic and exposure to the elements.

  The door sweep can also degrade, losing its ability to effectively seal against the threshold.

These seemingly minor issues accumulate, eventually resulting in a noticeable and problematic gap.

The High Cost of a Little Crack

The consequences of ignoring a door gap extend far beyond a slight breeze.

The most significant impact is on your energy bills. Gaps allow heated or cooled air to escape your home, forcing your HVAC system to work harder and consume more energy to maintain a comfortable temperature.

• Increased Heating/Cooling Costs: Studies have shown that air leaks around doors and windows can account for a significant portion of a home’s energy loss. A seemingly small gap can add substantially to your monthly expenses.

Beyond monetary costs, door gaps also compromise your home’s comfort.

Drafts create cold spots in winter and make it difficult to maintain a consistent temperature throughout your home.

In summer, the influx of hot air and humidity can make your air conditioner work overtime, and lead to an uncomfortable, sticky environment.

How the Threshold Extender Seals the Deal

An exterior door threshold extender provides a simple and effective solution to this problem.

• Bridging the Gap: The extender essentially raises the height of your existing threshold. This allows the door’s weather stripping or door sweep to make a proper seal, effectively blocking airflow.

  The extender creates a solid barrier against drafts, moisture, and pests.

• Customizable Fit: Extenders are available in various heights and materials to suit different door sizes and styles.

  This ensures a snug, weathertight fit that maximizes energy efficiency and comfort.

By understanding the causes and consequences of door gaps, and how a threshold extender addresses these issues, you can make an informed decision about improving your home’s energy efficiency and comfort.

Gather Your Supplies: The Right Tools for the Job

As we’ve seen, a door gap can be a real problem. But what exactly causes these gaps to form, and why is it so important to address them with a solution like a threshold extender? Let’s move on to what you’ll need to accomplish this DIY project.

Before diving into the installation, gathering the right tools and materials is crucial for a smooth and successful project. Having everything on hand will save you time and frustration.

Here’s a comprehensive list of what you’ll need:

Essential Tools and Materials

• Exterior Door Threshold Extender:

  This is the heart of the project. Choosing the right size is paramount. Measure the height of the gap you need to fill before purchasing.

  Also, consider the material. Aluminum is durable and weather-resistant, while wood can be a good option if you prefer a natural look and feel.

• Measuring Tape:

  Accurate measurements are essential. A good measuring tape will ensure a precise fit for your threshold extender.

• Saw (Circular, Hand, or Miter):

  You’ll need a saw to cut the extender to the correct length.

  • A circular saw is best for straight, quick cuts.
  • A hand saw offers more control, especially for angled cuts.
  • A miter saw provides the most precise and repeatable cuts, ideal if you’re doing multiple doors.

• Screwdriver (or Drill with Screwdriver Bit):

  For securely fastening the extender to the threshold. A drill with a screwdriver bit will make the job faster and easier. Choose screws that are appropriate for the material of your threshold.

• Caulk (Exterior Grade):

  This is vital for a weatherproof seal. Exterior-grade caulk is designed to withstand the elements and prevent water from seeping in. Make sure it’s paintable if you plan to paint the threshold.

• Shims:

  These thin, tapered pieces of wood are used for leveling the extender. They ensure that the extender is perfectly aligned with the door.

• Safety Glasses:

  Safety First! Always wear safety glasses when cutting or drilling to protect your eyes from debris.

Choosing the Right Tools

Selecting the right tools can make a significant difference in the ease and quality of the installation.

Consider these points:

• Threshold Extender Material: Choose a material that complements your existing threshold and door. Aluminum is a popular choice for its durability and weather resistance. Wood can be painted or stained to match your door.
• Saw Selection: If you’re comfortable with power tools, a circular or miter saw will speed up the cutting process. However, a hand saw offers more control, especially for beginners. Always use a sharp blade for clean, accurate cuts.
• Screwdriver Considerations: A cordless drill with a screwdriver bit is a worthwhile investment for this and other home improvement projects. Ensure you have the correct bit size to avoid stripping the screw heads.
• Caulk Quality: Invest in a high-quality, exterior-grade caulk that is specifically designed for sealing gaps around doors and windows. Look for a caulk that is paintable and mildew-resistant.
• Shim Material: Wood shims are inexpensive and readily available at most hardware stores. Plastic shims are another option, but may be more difficult to cut.

Having these tools and materials ready will set you up for a successful and efficient threshold extender installation, leading to a more comfortable and energy-efficient home.

Having the right tools is half the battle. With everything prepared, you’re now ready to tackle the installation process itself. Here’s how to do it.

Step-by-Step Installation Guide: Sealing the Gap

This section provides a clear, step-by-step guide to installing your exterior door threshold extender. Follow these instructions carefully to achieve a proper seal and eliminate that troublesome door gap.

Step 1: Measure the Gap with Precision

The first and arguably most important step is accurately measuring the height of the gap beneath your exterior door. This measurement will dictate the required height of your threshold extender.

Use your measuring tape to determine the distance between the bottom of the door and the top of the existing threshold. Take multiple measurements across the width of the door, as the gap may not be uniform due to settling or warping. Use the largest measurement to ensure the extender will completely seal the gap.

Step 2: Prepare the Threshold for Adhesion

Before installing the extender, you must thoroughly clean the existing threshold surface. This ensures proper adhesion of both the extender and the caulk.

Use a scraper or putty knife to remove any loose debris, old caulk, or dirt.

Then, use a degreaser or all-purpose cleaner to remove any grease or oil residue.

Finally, wipe the threshold clean with a damp cloth and allow it to dry completely before proceeding. A clean surface is essential for a long-lasting, weatherproof seal.

Step 3: Cut the Extender to the Correct Length

Carefully transfer your measurements to the Exterior Door Threshold Extender. It’s always better to cut slightly long and then trim, rather than cut too short.

Using your chosen saw, carefully cut the extender to the correct length.
Safety glasses are a must for this step.

If using a circular or miter saw, ensure the blade is appropriate for the material of the extender (e.g., a fine-tooth blade for aluminum).

If using a hand saw, maintain a steady, even stroke to achieve a clean, straight cut.

Double-check your measurements after cutting to ensure a perfect fit. A precise cut is crucial for a seamless installation.

Step 4: Install and Secure the Extender

Positioning and Leveling

Position the cut extender on the prepared threshold. The extender should fit snugly against the bottom of the door when it is closed.

Use shims to ensure the extender is perfectly level. Place shims underneath the extender as needed until a level surface is achieved. This is critical for proper door operation and weatherproofing.

Securing the Extender

Once the extender is level, it’s time to secure it to the threshold.
Using your screwdriver (or drill with screwdriver bit), drive screws through the extender and into the threshold.

Choose screws that are appropriate for the material of both the extender and the threshold.
Pre-drilling pilot holes can help prevent splitting, especially when working with wood thresholds.

Space the screws evenly along the length of the extender to ensure a secure and even attachment.

Step 5: Seal the Edges for a Watertight Finish

The final step is to apply a bead of exterior-grade caulk along all edges of the extender where it meets the threshold and the door frame. This creates a watertight seal that prevents drafts and water damage.

Apply the caulk smoothly and evenly.
Use your finger or a caulk smoothing tool to create a clean, professional-looking finish.

Remove any excess caulk with a damp cloth. Allow the caulk to cure completely according to the manufacturer’s instructions before exposing it to moisture.

Having the right tools is half the battle. With everything prepared, you’re now ready to tackle the installation process itself. Here’s how to do it.

Step-by-Step Installation Guide: Sealing the Gap
This section provides a clear, step-by-step guide to installing your exterior door threshold extender. Follow these instructions carefully to achieve a proper seal and eliminate that troublesome door gap.

Step 1: Measure the Gap with Precision
The first and arguably most important step is accurately measuring the height of the gap beneath your exterior door. This measurement will dictate the required height of your threshold extender.

Use your measuring tape to determine the distance between the bottom of the door and the top of the existing threshold. Take multiple measurements across the width of the door, as the gap may not be uniform due to settling or warping. Use the largest measurement to ensure the extender will completely seal the gap.

Step 2: Prepare the Threshold for Adhesion
Before installing the extender, you must thoroughly clean the existing threshold surface. This ensures proper adhesion of both the extender and the caulk.

Use a scraper or putty knife to remove any loose debris, old caulk, or dirt.
Then, use a degreaser or all-purpose cleaner to remove any grease or oil residue.
Finally, wipe the threshold clean with a damp cloth and allow it to dry completely before proceeding. A clean surface is essential for a long-lasting, weatherproof seal.

Step 3: Cut the Extender to the Correct Length
Carefully transfer your…

Finishing Touches: Achieving a Professional Seal

The installation is nearly complete, but don’t skip these final steps. They are crucial for ensuring a professional, long-lasting result and optimal door function. Attention to detail at this stage will prevent future headaches and maximize the benefits of your new threshold extender.

Cleaning Up Excess Caulk

A bead of caulk provides that essential weather-tight seal, but excess caulk can detract from the overall appearance.

• Immediate Removal: While the caulk is still wet, use a damp cloth or sponge to wipe away any excess that squeezed out during application.
• Smooth the Bead: For a clean, professional look, run a gloved finger or a caulk smoothing tool along the caulk line. This will create a smooth, consistent bead.
• Cured Caulk Removal: If the caulk has already dried, carefully use a utility knife to trim away the excess. Be careful not to damage the surrounding surfaces.

Testing Door Operation

Once the caulk has fully cured (refer to the manufacturer’s instructions for drying time), it’s time to test the door’s operation.

• Smooth Opening and Closing: Open and close the door several times to ensure it moves smoothly across the threshold extender.
• Check for Binding: Listen for any rubbing or binding. If the door sticks or is difficult to operate, the extender might be too high in certain spots.
• Addressing Binding: If binding occurs, identify the points of contact. You might need to carefully sand down high spots on the extender or add shims in low spots to achieve a level surface.

Identifying and Sealing Remaining Gaps

Even with careful installation, small gaps may still exist. Don’t ignore these! They can compromise energy efficiency and allow drafts.

• Visual Inspection: Carefully inspect the entire perimeter of the threshold extender, both inside and outside the door. Look for any visible gaps or cracks between the extender, the threshold, and the door.
• The "Paper Test": Close the door and try to slide a piece of paper between the door and the threshold. If the paper slides easily, there’s a gap that needs sealing.
• Caulk Application: Apply a thin bead of exterior-grade caulk to any remaining gaps. Smooth the caulk with a wet finger or a smoothing tool for a seamless finish.
• Weatherstripping Adjustment: If the gap is between the door and the door frame (above the threshold), consider adjusting or replacing the door’s weatherstripping to create a complete seal.

Carefully transferring your measurements and making precise cuts are vital steps. But the job isn’t quite finished after installation. The longevity and effectiveness of your newly installed threshold extender depend on proper maintenance and addressing any underlying issues that could compromise its performance.

Maintenance and Long-Term Care for Your Threshold Extender

Installing an exterior door threshold extender is a great way to improve your home’s energy efficiency and weatherproofing. However, like any home improvement project, it requires ongoing maintenance to ensure it continues to perform its best. Neglecting maintenance can lead to premature wear and tear, compromising the seal and negating the benefits you initially sought.

Regular Inspections: A Proactive Approach

The cornerstone of any good maintenance plan is regular inspection. Make it a habit to visually inspect your exterior door threshold extender at least twice a year – ideally during the spring and fall, when you’re already preparing your home for seasonal changes.

Look for any signs of:

• Physical damage, such as cracks, chips, or dents.
• Discoloration or staining, which could indicate water damage or mold growth.
• Separation from the threshold or door frame.
• Loose screws or fasteners.

Addressing these issues early can prevent them from escalating into more significant problems.

Caulking: Maintaining the Weatherproof Seal

The caulk seal around your threshold extender is your first line of defense against water infiltration and drafts. Over time, caulk can dry out, crack, or peel away, compromising its ability to create a tight seal.

• Inspect the caulk during your regular inspections, paying close attention to areas where it meets the threshold, door frame, and extender.
• If you notice any cracks or gaps, remove the old caulk using a caulk remover tool or a utility knife. Be careful not to damage the surrounding surfaces.
• Clean the area thoroughly to remove any residue.
• Apply a fresh bead of exterior-grade caulk, ensuring it fills the gap completely and creates a smooth, even surface.
• Smooth the caulk with your finger or a caulk smoothing tool for a professional finish.

Re-caulking as needed will maintain a watertight seal, preventing water damage and energy loss.

Addressing Underlying Issues: Beyond the Extender

Sometimes, problems with your threshold extender are symptomatic of larger issues with your door or door frame. Ignoring these underlying problems can shorten the lifespan of your extender and lead to recurring issues.

• Door Warping: If your door is warped, it may not be making consistent contact with the threshold extender. This can create gaps and allow drafts to enter your home. Consider replacing the door or having it professionally adjusted.
• Frame Damage: A damaged or improperly installed door frame can also contribute to gaps and drafts. Inspect the frame for signs of rot, decay, or misalignment. Repair or replace the frame as needed.
• Settling Foundation: In some cases, settling of your home’s foundation can cause the door frame to shift, creating gaps around the door. Consult with a foundation specialist to address any structural issues.

By addressing these underlying issues, you can ensure that your threshold extender continues to perform its best for years to come. A little preventative care can save you from future headaches.

So, there you have it! Fixing that door gap with an exterior door threshold extender is totally doable. Give it a shot and enjoy a warmer, more energy-efficient home. Happy fixing!