I answered a question on this sites sister site and thought it would be a good discussion so I have re-written it in the form of a new topic.
The question that came up was why was the sill on the Alside Sheffield so tall? Here is my answer to the question as well as my take on some basic window design.
The reason the Sheffield sill is very tall sill is because it is not really a true sill...... It is a side jamb with thick snap-ins on top.
It is much cheaper for a factory to use the same extrusion on all 4 sides. This way, all they need to cut the frame pieces is a 45 degree chop saw, and a simple straight line welder. It is a cheap way to make a window even though it doesn't make a quality well designed window, and as a factory you don't have to spend millions on robotic equipment that can cut and weld dissimilar profiles.
The red in the picture is the "side jamb" piece they use as the starting point for their sill. The blue in the photo is the snap in piece that transforms the "side jamb" into a sill. Note how the screen track sticks up past the sill. This screen track sticking up has a couple holes through it to drain to the outside, but much of the water can seep through down into the extrusion....where you can't get to for cleaning.
Many of you out there keep asking us, "what makes a good window". In my opinion, here is a real good chance to learn some basics about window construction and to know one more thing to look for in a window that has a good design. On the other site, eberry pointed out one flaw with the handle that has been spoken about here before, which is that when you lift up on the handle snap-in, it puts stress on the glass.( figure - 8 ) Many other windows have this handle extruded right into the sash rail
The bottom photo shows a window that has a similar side jamb profile to the previous photo, but has a dedicated sill...a sill that was made as a sill.
This factory has spent the extra money on sophisticated machinery to cut and weld dissimilar extrusions to provide you with a sloped sill that provides proper drainage and keeps the glass loss to a mininum. The sill is not being used as a multichambered gutter to get rid of water that leaks in through the snap-ins...because there are none.
In your window shopping, if you can distinguish between these two styles of window sill construction, that is one place where you can narrow your search on finding a decent trouble-free window.
One giveaway on detecting the difference is that on a window with snap-in sill pieces, the beveled screen track on the outside will look identical on all 4 sides. With a window with a dedicated sill, the screen track will look totally different.
Also, many of these type windows with snap-ins will have pocket sills, where the bottom sash goes down into a hole in the sill.
This is my take on sill design. I am sure there are many installers and also the factories that make them that would disagree with me.
Window construction, what makes one better?
- Window4U (IL)
- Posts: 1374
- Joined: Fri Mar 11, 2005 3:58 pm
- Location: Sales and Installation in Chicagoland and Central Illinois
Window construction, what makes one better?
Last edited by Window4U (IL) on Thu May 11, 2006 5:35 pm, edited 1 time in total.
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