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9 Window Installation Mistakes & How To Avoid Them

Written on April 16, 2025
room with a dining table

Key Takeaways

  • Gaps, drafts, and water damage are among the common signs that a window is not installed properly.
  • Always double-check window measurements to avoid gaps and drafts.
  • Follow manufacturer instructions closely to maintain warranties.
  • Consider hiring professionals for your window installation to avoid costly errors.
  • Panda Windows & Doors provides many window types, including awning, hopper, and fixed windows.

Why Correct Window Installation Is Important

  1. Energy Efficiency: Proper installation involves tight sealing to prevent air leaks and maintain a consistent temperature, which reduces the workload on HVAC systems and lowers your energy bills.
  2. Security: Properly installed windows are more secure and resistant to tampering - deterring potential intruders.
  3. Aesthetics: Correct installation enhances the appearance of windows and adds to the curb appeal of your home.
  4. Prevention of Water Infiltration: Proper installation creates a continuous barrier against the weather to prevent water from entering your home through gaps and cracks, which can lead to structural damage and mold growth.
  5. Long-Term Savings: Windows that are correctly installed function optimally, reducing the need for frequent repairs and replacements.
  6. Condensation Prevention: It prevents condensation problems that can lead to rotting and damage to the window frame and surrounding structure.

Since our founding in 1991, Panda Windows & Doors has specialized in state-of-the-art custom glass wall systems for both residential and commercial spaces. Operating from our manufacturing facility in Las Vegas, Nevada, we have been at the forefront of innovation for over 30 years. Our product offerings, which include over 80 high-end options, such as pivot doors, French doors, folding doors, lift & slides, multi-slides, horizontal sliding walls, and operable windows, are available in a range of materials, including aluminum, steel, stainless steel, bronze, solid wood, and aluminum-wood clad.
Our company is widely recognized for its award-winning designs, engineering solutions, and rapid delivery times. We ensure that our customers throughout the U.S. and Caribbean receive their products within 6-10 weeks. Our company is trusted by leading architectural firms and glaziers nationwide, and we stand as the premier manufacturer of custom luxury windows and doors in the United States.
Learn About Custom Solutions from Panda Windows & Doors Today

9 Signs That Your Window Is Not Properly Installed

window

Choose a window rated for energy efficiency by NFRC to save on your heating and cooling costs.

1. Drafts: Feeling cold air coming in around the window.

2. Gaps: Noticeable gaps between the window frame and the wall or sill.

3. Water Damage: Water stains or damage around the frame or sill.

4. Foggy Window Panes: Condensation between the panes of glass.

5. Difficult Operation: Windows that are hard to open, close, or lock.

6. Strange Noises: Squeaking, creaking, or cracking sounds when opening or closing the window.

7. Messy Caulking: Uneven or poorly applied caulk around the window.

8. Leftover Mess: Debris, dust, or adhesive residue left after installation.

9. Misalignment: Crooked windows or frames that are not square.

9 Window Installation Mistakes And Their Solutions

1. Incorrect Measurements

  • Mistake: Inaccurate measurements of the window opening result in windows that are either too small or too large.
  • Solution: Use a steel tape measure to determine the width at the top and bottom and the height in three places: the center and each side.

2. Wrong Size Jambs

  • Mistake: When ordering windows with jambs attached, failing to account for the finished surface of interior walls that are thicker than half an inch of drywall or sheathing thicker than 7/16 of an inch.
  • Solution: Add to the jamb width to accommodate thicker materials.

3. No Back Slope

  • Mistake: The sill of the rough opening is not sloped to direct water away from the building.
  • Solution: Create a back slope on the sill by cutting cripple studs at an angle or adding a sill wedge or sloped pan.

4. Dirty Surfaces

  • Mistake: Installing a window on a dirty surface, preventing a tight seal.
  • Solution: Clean the base of the frame carefully before installing. Remove dust or plaster fragments for proper adhesion.

5. Improperly Fixed Windows

  • Mistake: Installing windows using only foam, omitting mechanical connectors like sill strips or connectors. Also, using too many connectors.
  • Solution: Install windows with sill strips or connectors, following the manufacturer's fastener schedule. And, make sure you are not using too many connectors, which can risk warping the window due to temperature fluctuations.

6. Incorrectly Sealed Windows

  • Mistake: Failing to seal windows correctly.
  • Solution: Apply a 3/8” bead of sealant to the back side of the nailing flange, but leave the bottom open for drainage.

7. Not Following Instructions

  • Mistake: Failing to follow the manufacturer’s specific instructions for the window being installed.
  • Solution: Review and adhere to the manufacturer's instructions for proper performance and maintaining the warranty.

8. Not Accounting for Expansion and Contraction

  • Mistake: Not allowing for expansion and contraction of window materials.
  • Solution: Accommodate expansion and contraction by using a 3/16” barrier for a caulk joint on the exterior. A backer rod can be used for larger gaps.

9. Not Purchasing Quality Windows

  • Mistake: Buying the least expensive window or from an untrustworthy brand.
  • Solution: Choose Panda Windows & Doors, which has been a trusted brand for custom luxury windows since 1991.

Read More: 7 Door Installation Mistakes & How to Avoid Them

Choose Panda Windows & Doors For Your Custom Window Designs

window

Panda Windows & Doors’ windows have dual-glazed, low-E, tempered glass for improved energy efficiency and security.

As a leading producer of custom luxury windows and doors in the United States, we at Panda Windows & Doors dedicate ourselves to providing unparalleled, industry-leading, premium-grade products for both residential and commercial projects.

If you're seeking the perfect window, here's why you should choose us:

1. Custom Focus: We focus on custom luxury windows and doors to deliver unique and innovative solutions.

2. Innovation: We prioritize product development and refinement.

3. Material Options: You can choose your window material from sustainable options like aluminum, steel, stainless steel, architectural bronze, and wood.

4. Design Capabilities: With 85 state-of-the-art products, numerous configurations, and a multitude of options for colors, glass, and finishes, we can lift the elegance and effectiveness of any space.

5. Testing & Performance: Nearly all our products are independently certified by the NFRC and AAMA, with many High Velocity Hurricane Zone (HVHZ) approved options.

Reach out to us to learn more about our products and get a free quote.

Frequently Asked Questions (FAQs)

What steps are involved in DIY window installation?

1. Removing the old window.

2. Preparing the window opening.

3. Mounting the window.

4. Installing anchors.

5. Installing window fittings and handles.

6. Sealing the window.

7. Installing the inner window sill.

8. Carrying out finishing work.

Should I hire a professional or DIY the window installation?

DIY window replacement is a serious undertaking and can result in many mistakes, especially if you are doing it for the first time. Thus, we recommend professional installation for the best performance of your window.

Do I need to move out during the window installation?

No, you won’t need to move out of your home during the installation.

What makes a window "high-quality?"

High-quality windows have strong construction, energy-efficient components like insulated glass with argon or krypton gas, and certification from programs like ENERGY STAR and NFRC. Also, they are engineered with quality materials to prevent issues like warping, peeling, and moisture damage.

Are Panda Windows & Doors products sustainable?

Yes! All our products are made with abundantly available and highly recyclable materials. Our aluminum extrusions are made of 70-75% recycled content, and steel extrusions are made of 26.1% recycled content. We also recycle 100% of our aluminum scraps and ship our products in wooden crates made from sustainably sourced wood.

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