When you're installing wall components in wall penetrations, you should always use flashing tape to maintain the integrity of your wall structure for years to come. It only takes four steps to apply. But first, what type of flashing tape should you use? Consider the following options.
There are three common types of flashing: metal, non-adhering, and self-adhering. Of these three types, the self-adhering flashing tape excels in three crucial areas: environmental durability, adhesive durability, and ease of installation.
1. Environmental durability
Before wall components (e.g. windows) are installed, wall cavities may be left exposed during weeks or months of construction. Environmental elements such as weather and temperature changes can damage the exposed material, so you want a flashing tape that will act as protection while your wall components are yet to be installed. Also, flashing tape acts as a window insulation after construction has been completed. It will protect the interface between your window and wall penetration, keeping heat, air, and moisture out of the structure.
2. Adhesive durability
The primary role of window flashing tape is to act as a window seal. This means that the adhesive should be durable enough to withstand both moisture and getting wet. It should act as a water barrier while also allowing the moisture to escape from within.
3. Ease of installation
The best thing about self-adhering flashing tape is how easy it is to install. With this type of flashing, you can finish installing a window in just four easy steps. Speaking of installation, here’s a description of how you can use DuPont Flashing Tape to install a rectangular integral flanged window to your wall.
HOW TO APPLY FLASHING TAPE:
Step 1: Preparing the wall cavity.
Prepare the wall cavity by attaching a house wrap and water-resistive barrier (WRB) apron under the sill. (If you're using Dupont Flashing Tape, you'll have to use the DuPont Tyvek HomeWrap for this step.) Measure the apron by adding 20 inches to the length of the rough opening jambs so that each end of the Tyvek house wrap extends 10 inches beyond the jambs.
Step 2: Flashing.
Before you apply the DuPont FlexWrap to the sill, you should clean the surfaces of the wall cavity first. And then, proceed by attaching the Dupont FlexWrap to the sill and the jambs (up to at least 6 inches on each jamb), making sure that the corners lay flat. Afterward, secure it to the wall (not the sill) with mechanical fasteners.
Step 3: Flashing and installing the window
Prepare the wall cavity for window installation by caulking the head and the jambs of the cavity. Then, following the window manufacturer’s instructions, insert your window into the cavity. After the window has been correctly placed, attach two strips of the DuPont Flashing Tape to the jambs. (Each strip should extend an inch above the head flange and below the bottom edge of the sill flashing.) Lastly, apply another strip of flashing tape to the head, making sure that the strip extends beyond the outer edges of each jamb flashing.
Step 4: Finishing the installation
To finish off the installation, add another layer of security between the window and the wall cavity by sealing the perimeter with caulk from inside the house. Next, attach the DuPont Tyvek HomeWrap WRB and the DuPont Flashing Tape to the head and jambs. Lastly, lap the apron and WRB over your building materials with the proper shingling.
And voila! You have successfully installed a window using the DuPont Flashing Tape! Easy, right?