RetroFit Windows Problem

Preface on Retrofit windows

This article pertains to leaks caused by the improper installation of retrofit windows. They have inherent problems when installed in incorrect locations, particularly in places without a significant roof overhang. This has nothing to do with the actual quality of a retrofit window or leaks present in the early versions that were poorly manufactured or engineered

Any problems with window quality should be covered by your window warranty. however the issues we are discussing are not covered by any window warranty that I am aware of.

New construction retrofit windows
New construction retrofit windows

You get what you pay for

When it comes to your window installation, it can only really be done with two of the following “fast, right, or cheap”. Any savvy home owner should remember this when they hear a sales pitch promising “low cost windows that preserve the original framework and can be installed for as little as a few hundred dollars”. These lines are used to promote retro-fit windows. In certain circumstances, agreeing to this install can be one of the biggest mistakes a home owner can make. That is not to say they are always bad, but they are very problem prone. Before you install any of these windows, there are a few things that you should understand in order to protect your home.

Retrofit windows are a Salesman’s Dream

Contractors love to sell these windows. They are easy to install, rarely require a permit, and save a lot of time. On paper, it looks like there’s no downside. You save money. The contractor saves time. Everyone walks away happy, right? Sort of, but not really. The main problem with installing a retrofit window is moisture accumulation.

Inability to Breathe

A retrofit window is assembled in a way that doesn’t allow for a lot of air flow. Normal windows require flashing paper over the nailing fin on the top and sides of the window and under the nailing fin on the bottom. This paper acts much like shingles on a roof, preventing water from getting behind the window frame while allowing many opportunities for water to escape. This creates a primary drainage route for moisture in a normal window in the small gap between the stucco and the metal window frame. However after a retrofit window is installed, this gap is covered with a trim piece. This piece is then securely caulked in place, trapping moisture.

Trapping Water

While this trim piece does prevent water from getting behind the window, it closes the normal exit for the moisture that has already permeated the wall’s painted exterior. This trapped moisture will exploit any imperfection in the flashing papering of your home and as it accumulates, gravity will push it down into a newly created channel between the retrofit window trim and the old original window nailing fin. Once trapped, this water is pushed under the paper and up over the nailing fin into your house. This generally happens at the top of the window even though the moisture may not present itself on the inside of the house. until it has run down to the bottom of the window.  We’ve seen it happen many times and it is not pretty.

Location is Important!

For these windows to work, placement is key. The walls surrounding the window need to be dry at all times. The easiest way to ensure this is to place them only on walls with adequate roof overhang. A retrofit window should always be shielded by a roof that extends far enough out to prevent rainwater from wetting the wall above the bottom of the window. While salesmen may assure you retrofit windows are “watertight” and protected by a “sill pan, flash tape, or housing wrap”, it is all essentially useless if there isn’t adequate overhang. If the wall immediately surrounding a retrofit window gets wet, your home will suffer.

Tying the House Together

Finally there are the aesthetic considerations. A retro fit window has a vinyl border that cannot be painted. I have seen people try, but the paint rarely sticks. The color of your vinyl window should be considered final. The new trim will also be bulkier and more noticeable. This addition will cut into the size of the window itself and can cut the window glass back anywhere from an inch to a foot. When the window loses surface area, less light will be able to enter and often makes a bigger difference than most expect.

So before you buy into speels about retro fit windows claiming to save you time and labor costs, remember these tips. We have seen many people oversimplify this purchase and it has almost always cost them down the road. Hope this article helps and happy window shopping!

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