Window prep for an EIFS application
Proper window prep for an EIFS application is very important
With new construction EIFS it is imperative to get the EIFS contractor in on the job site before the windows go in, so they can treat the window frames before they go in. If this is not done the entire system has a chance of failure before it even begins. Lets face it even the best windows can leak, and most times you did not buy the best, so it is a safe beat that sooner or later the windows will leak. If the window frame is now treated this is a recipe for disaster down the road. Even if you do not want or cannot get the EIFS guy down there before hand to treat the windows do it yourself. Simply apply flashing tape around the window frame. It has to cover the entire window jam, and come out on the face about 4 inches. Make sure the corners are cover well, and that there are no wrinkles in the tape. Of course, the EIFS manufacturers (Dryvit, Senergy, Sto) all carry a brand of the flashing tape, but in a pinch you can buy flashing tape at the local hardware store if it is going to be the difference between having all your windows protected or not. You may want to contact the EIFS manufacturer you are using for the project, and find out if not using the flashing tape, or not using the correct flashing tape is going to void your material warranty.
What happens when the windows are already in?
What should happen is that the windows come out, and the windows are treated with flashing tape. If the windows are not done correctly there is a good chance you are voiding the warranty. The specifications from the material manufacturer are very clear on the application of flashing tape around the windows.
How do you apply the Flashing Tape?
You start at the bottom of the window sil. The Flashing tape should go all the back to the inside edge of the sil jam, and down four inches onto the face of the wall. The tape should be cut six inches longer than the window opening to allow the tape to go up the window frame on each side by at least three inches. Use your knife to cut along three inch vertical and lay the tape down on to the face of the wall. Make sure there are no wrinkles in the tape. Apply a small piece of tape in the corner that goes all the way to the edge of the sil jam out and onto the face of the wall at least four inches. The apply the two verticals the same way and finally the top of the window is applied.
What qualifies as Flashing Tape when it comes to EIFS?
When it comes to EIFS there are very trick rules, and variations of products is to be done very carefully as not to void your warranty. I will use Dryvit® and its particular material line to address these products used for window treatments. There are several products you can use to treat the windows with. Dryvit’s AquaFlash® being one of the best.
This post actually started from another post, and I wanted to expand on it as it is such an important topic.