New windows and stucco … the essentials

How cutting through stucco affects window replacement A home with stucco walls poses a challenge when installing new windows. Under the stucco is waterproof black building paper, or Tyvek in some cases, which seals the exterior envelope.

When installing a new window, the installer must cut through the building paper, potentially exposing your wood frame to rot Greg Martineau Projects has tried-and-tested techniques to deal with this problem. GMP gives a 10-year warranty on our installation.

Seal the exterior envelope

GMP starts with a polythene lining made with rubberized tape going over the bottom plate of the window opening and up the sides at least 8 inches. The new window is then placed into the hole and fastened to the wall.Adhesive waterproof membrane goes on both sides and then over the top, covering the new nail fin. (The nail fin is a right-angled metal border that allows the window to be securely nailed to the framework of the house.)

Replace drip flashing above the window

A metal drip flash drains water away from above the window. A new drip flash is not needed because we use an adhesive membrane above the window and seal it to the existing black paper with high quality caulking. Properly installing the membrane without tearing the paper is, in most cases, a better way of ensuring a seal than trying to get an aluminum drip cap back on. The continuous seal is the most important thing even if part of that membrane is caulking. Whatever problems we face on a home of any age, GMP will work to ensure that the black paper or Tyvek continues to work as a continuous seal around your home, preventing rot and drafts.