This is an old house with 2040 windows. I’ll be using new construction due to the cost of retrofit. I noticed on Home Depot that 4020’s were 1/3 less than the 2040’s. What the difference? Looks like the slider will split the middle.
To prevent moisture buildup and improve performance, install a continuous air barrier—such as drywall or specialized membranes—under tongue-and-groove boards or other interior wall paneling.
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Replies
Windows have drain slots in the bottom. If you turn them on their side, rain water won't drain out.
also...
they probably won't open easy at 90* to their designed positioning, and there's the weatherstripping......
Ron
I came across a job that must have ordered dbl hungs and laid them on their side and you are right-
Water was actually directed inside.
But then I've also heard from less than reputable suppliers-oh yeah, for a slider we just use a dbl hung on it's side.
Clever those guys.
There are some casements that are designed for either orientation, but I wouldn't attempt it with sliders unless you get a gold-plated guarantee from the manufacturer.
Slider/single hung
The industry standard for window rough openings is the callout size is the rough opening size, so yes a 4020 layed on it's side should fit in the same opening as a 2040 (this hasn't always been the case for rough openings though, so you'll have to check your rough opening if you are replacing an existing window).
But just because it FITS doesn't mean you should do it.
Single hung windows (or double hungs) have balancing hardware to keep the sliding sash(s) open...kind of a rolled spring on each side of the sash that extends and retracts as the sash slides up and down.
A sliding unit does not have the same hardware. It has glides on the bottom that follow a track, allowing it to move freely side to side, but if you tip that slider up on it's side it won't stay open.
They look similar. And they are sized the same. But they are DIFFERENT. A single (or double) hung won't operate properly on it's side and a slider won't operate properly on IT'S side.
Plus, the issues others have mentioned about the weep path/water intrusion/weather stripping.
You COULD do it. But you SHOULDN'T.