How to Air Seal and Install Windows for Lasting Durability

Hey, what’s up everybody? It’s TJ with Sanctified Homes, and today we’re talking about an important aspect of building that often gets overlooked—how to properly air seal and install windows. This process is crucial for ensuring your home stays durable, energy-efficient, and free from moisture issues. Let's dive into how we get this done the right way, step by step.

1. Preparing the Window Opening

The most important part of installing a window is getting the window opening prepped correctly. If you've been following along with our Bushel Hill Haven project, you might already know we like to start by building window bucks.

For those unfamiliar, a window buck is a frame built inside the rough window opening. Here's the special touch we add: the bottom sill of the window buck is sloped at a 5° angle. Why does this matter? Because if any water ever gets behind the window, instead of pooling or leaking inside your home, the water will naturally run down and away thanks to that sloped sill.

2. Composite Shims for Longevity

Now that the window opening is sloped and ready, the next thing we need is shims. Shims help level the window and give it support. But, here's a common mistake to avoid: don’t use wooden shims. Over time, moisture can cause wood to rot, leading to potential window failures, like difficulties opening or closing the window.

Instead, we use composite shims, which are moisture-resistant and won't rot. These shims go under the window and ensure that it stays level without compromising durability.

3. Air Sealing and Taping for Maximum Protection

Before setting the window into the opening, we tape and seal the window buck. We use a high-performance tape like Weather Logic to wrap the opening and ensure continuity of the air seal layer from the outside of the house to the inside.

Here’s how the taping works:

• Tape goes around the top and sides of the window opening.

• We leave the bottom of the window untaped. Why? Because if moisture somehow gets in, it needs a way to escape. Sealing the bottom could trap water and cause rot or leaks over time.

Once the window is in place, we apply Lexel sealant to the sides and top but again, we avoid sealing the bottom to allow for moisture drainage. After the window is secured with screws, we tape the sides and top to seal any remaining gaps between the window frame and the house.

4. Air Dam and Backer Rod for Complete Sealing

Another key detail to ensure proper air sealing is the use of an air dam with a backer rod. The air dam is a foam or caulk material that seals the interior edge of the window, while the backer rod fills in larger gaps, preventing air leaks around the window.

At this stage, we’re not relying solely on tape for air sealing. The air dam and backer rod ensure a tight seal that will last for years, making the window more efficient and keeping your home comfortable through every season.

5. No Shortcuts: Every Detail Matters

Each step in this process—from the sloped sill to the composite shims to the precise taping—helps ensure your windows are properly installed for lasting durability. Remember, it’s not just about keeping water out; it's about air sealing too. Air leaks can lead to higher energy bills and less comfort in your home, especially in colder climates.

Even though we covered the big steps, it's important to pay attention to the finer details like:

• Which type of sealant and tape you use

• How to properly stretch tape over corners to prevent air or thermal leaks

• Ensuring continuous insulation and protection from the outside to the inside of the home

These small details may seem minor but can make a huge difference in how your windows perform over time.

Conclusion

Proper window installation is crucial for both durability and energy efficiency. By paying attention to details like sloped sills, composite shims, and ensuring proper air sealing, you can avoid future issues like rot, air leaks, and moisture damage. Remember, windows aren’t just an aesthetic feature; they play a huge role in the overall comfort and performance of your home.

If you have any questions about window installation or want to learn more about how we seal and prep our window openings, feel free to reach out. Whether you’re a contractor or a homeowner, we’re here to help you understand the process.

In the meantime, don’t forget to raise your standard, and we’ll talk to you guys soon!