One of the selling points of fiberglass frames is their very low window expansion and contraction rate.
If you have ever installed vinyl siding, you know that you have to allow for the siding to expand and contract. In some cases, a 12’ board of vinyl siding can expand and contract as much as a half and 1/2”!
Why do we trust the most vulnerable and important areas in our homes to a material that we know is moving around constantly due to the most basic forces of nature? Window expansion is a major problem!
Let’s face it, we live in an extreme environment, winters are stinking cold, and our summers are blazing hot. Is there a material that can handle this???
At SunRay we are believers in the science of Fiberglass frames.
Fiberglass frames are made of the same essential material as glass, fiberglass sash, and frames expand and contract at the same rate as the glass they hold, leading to fewer leaks. That is one of the reasons why fiberglass windows can last for up to 50 years!
How much does glass expand per degree impacting window expansion?
A piece of glass 2 meters in length (expressed in mm) subjected to an increase in temperature of 30°C will lengthen by 2000 x 9 x 10-6 x 30 = 0.54 mm. Theoretically, an increase of 100°C will cause 1 meter of glass to expand by approximately 1mm. If you love facts like this, learn more here.
This is negligible, we are not seeing a swing of 100 degrees even in our harsh climate…
So how much does vinyl expand?
It expands seven times farther than glass with each degree of temperature. This can cause the seal between the vinyl framework and the glass to fail. The problem increases with the size of the window; the bigger the sash, the sooner it fails.
Wow! This is a problem, we have two different materials that are designed to never come apart but also need to be able to move at different rates. We are asking a great deal of our vinyl windows. It’s like throwing the kids in the back seat for 8 hours straight and asking them not to fight. There will be conflict. When it comes to windows, sealed units usually pay the price by showing a leak sooner or later. And then we see the fog inside the window panes, meaning that the window needs replacing.