Something we encounter fairly often while doing home inspections is a hidden danger unnoticed by the house buying public, and probably often overlooked by home inspectors is the dreaded screw in the bottom track of a sliding retrofit vinyl window. Today we will discuss vinyl retrofit windows and their proper installation. Not following these guidelines can result in possible moisture intrusion in the wall below the window which in turn can invite mold, wood destroying pests and decay.
For years I was partner in a company where we installed retrofit vinyl windows on several hundred homes in the San Diego area. Most of our work was done on military housing projects. So I have seen my share of vinyl windows in my day. Vinyl retrofit windows install within a home's existing window frame and rely on the weatherproofing that exists between the house and the original window. To install these windows one simply has to remove the sliding portion of the existing window, the fixed glass, perhaps do some slight modifications to the existing window sill and install the new vinyl window assembly.
Most all window manufacturers follow the installation guidelines set forth by the American Architectural Manufacturers Association or AAMA. Their guide 2410-03 (pdf) sets the standard for the proper installation of vinyl retrofit windows. The AAMA prohibits the use of fasteners at the sill of the vinyl window that would penetrate the existing window. Why? Because when rainwater fills the bottom track of the new vinyl window and find this screw hole, water will travel down the screw, pass through the existing window frame and be deposited in the wall cavity below resulting in potential moisture problems.
Case in point. While on a home inspection this week in Mira Mesa on a recently flipped single-family home it was noted that some shortcuts were taken in certain phases of the renovation. New sinks installed without waste traps, outlets wired improperly etc. As these types of issues are found all too often with homes
that have been recently flipped, it forces us to take a different tact
Gentle pressure lifts the track out then we would normally take during a home inspection
and look for all the little details that might have been overlooked during this home's renovation. Improperly installed vinyl retrofit windows certainly is high on the list of things that are often done incorrectly.
The photo to the right shows how to discover if your windows have been installed using this flawed method. You will need to remove the small piece of vinyl that sits in the bottom track of your windows. Don't worry, this is very easy to remove and re-install using nothing more than a flat screwdriver or stiff putty knife. Gently apply pressure to the raised "bead" that the windows slides against. Pry it upward until you can get your fingers underneath it. Then, raise it up to observe the area below to determine if any screws have been placed in the bottom portion of the window.
Screw in bottom track can lead to water leaksNote the screw in the sill of the second photo. With recent rains in San Diego, moisture levels within this wall were excessive creating an area conducive to possible mold growth and termite activity.If you discover that your windows are screwed, you can contact the manufacturer of your vinyl windows for advice on how to properly seal this penetration. The manufacturers name is often on the locking mechanism for the window. Backing the screw out and applying a high-quality polyurethane sealant into the hole as well as around the screw head will certainly help in achieving a watertight assembly.
