When you think about new windows for your home things like beauty, functionality and energy efficiency may be things that immediately come to mind.
As you begin to get further along in your research process you’ll probably begin to add other things to your list of must haves. Some of the most important next things that should be on that list are what we’ll talk about during today’s discussion.
A window sash, as defined by Wikipedia is “…made of one or more movable panels, or "sashes", that form a frame to hold panes of glass.” The vast majority of replacement windows sold in the United States are windows with sashes.
So, as you’re making your way through the eight critical areas that you are researching before purchasing new replacement windows for your home, understanding the role that a window sash plays is very important.
A double hung has two movable sashes that move up and down, while a single hung has one. Sliders, on the other hand, have sashes that move from side to side. Casements and awnings have sashes that roll out using a cranking mechanism.
Then, there’s the largest sashed window…a sliding patio door which is really just two large window sashes that slide side to side.
Window Sash Challenges in Replacement Windows
Because a sashed window is a separate, movable piece of the overall replacement window structure, there are several challenges that a quality vinyl replacement window must address when it comes to these types of products.
- Strength—Because the sash, which is a smaller piece of vinyl than the frame it resides in, holds the glass, sash strength is an issue that shouldn’t allow for compromise. Especially in larger units, and casements and awnings where the sash actually moves outside of the frame, sash strength is paramount.
- Security—Movable units create potential security issues. Unfortunately with the increased threat of crime that we deal with each day, the security aspect of your new replacement windows is one that you can’t afford to ignore..
- Thermal efficiency—Movable sashes also present the potential for air leaks as well as other thermal issues, including heat and cold transfer.
Now you could do a window sash replacement only, depending upon the type of windows that you currently have, but just replacing sashes can leave you with some significant challenges.
Dealing with the Issues That Window Sashes Create in Replacement Windows
So, what’s the best way to deal with strength, security and thermal issues? We believe fiberglass can fill all of these needs. But, if that’s true, why not just go out and buy a fiberglass, or one the other “strong” composite types of windows? In our opinion, three reasons…
- Maintenance—Fiberglass/composites are not maintenance free materials like vinyl.
- Construction—Unlike the fusion welding process for vinyl replacement windows, fiberglass and composite frames have to be screwed together introducing the possibility of moisture and air leaking issues.
- Cost—Far and away, fiberglass, and other composite type of windows are the most expensive replacement windows in the marketplace.
Benefits of Using Fiberglass Inserts in the Window Sash on a Replacement Window
How do we, then, take advantage of the positives of fiberglass and composites, without having to deal with the negatives?
- Strength—We talked in a previous post about how 90 degree bends in vinyl (like with steel) help to make the overall piece stronger. In addition, we add fiberglass inserts into the ashes of several or our window products and our sliding patio doors to increase the overall strength of the sashes.
- Security—In some of the more crime ridden areas of the country, criminals have used heat to penetrate vinyl sashes to get at the locking mechanism. A fiberglass insert in the meeting rails thwarts this opportunity. By the way, another area to consider when you look at sash security is the lock itself, of course. One of the tests that high quality replacement windows go through is called a forced entry tests. Our products consistently are rated the highest, at 10 out of 10, on this important, security-related, test.
- Thermal efficiency—The most vulnerable point, from an efficiency standpoint, on a replacement window is where two movable sashes meet. You’ll find this most often in double hung and sliding replacement windows. Optionally inserting fiberglass into the sashes of a couple of our premium brands (standard in our sliding patio doors) really helps here. Fiberglass is considered to be a thermally dead material when it comes to the transfer of heat and cold.
Inserting the fiberglass into the already strong vinyl window sash allows us to take advantage of all the strength and thermal benefits of it, without having to deal with any of the negatives of fiberglass, and it's composite cousins.
As part of your overall research into the best vinyl replacement windows, don’t forget the window sash and its effect on the overall the strength, security and thermal efficiency of your new vinyl replacement windows.