Definition of ‘Net Window Dimension’?
FlyingContractor
| Posted in Construction Techniques on
Hey Guys,
I feel kinda silly posting this question, but I have heard conflicting answers so I wanted to run it by everyone. I always learned to order windows by their ‘rough opening’, stud to stud and header to sill plate or ‘finished opening’, sheetrock to sheetrock (I’m setting metal windows with no jambs) and header sheetrock to finished wood sill. My supplier is saying the only dimension that they have/need is the ‘net window dimension’, which to my understanding is the same as the finished opening. Am I correct here?
Thanks!
Replies
Bump.
I have no clue as to what a "net window dimension" is, or how it should relate to a rough opening, but that doesn't prove anything!
I would ask your supplier to define his term a little better, draw a picture and label it, or show you his supplier's diagrams.
Assumptions made in specification areas like this generally end up with someone not being happy. You, supplier, end user..........
Good luck!
Jim
Never underestimate the value of a sharp pencil or good light.
Edited 8/10/2007 2:14 pm ET by JTC1
To confuse matters even more.
Some Windows are specced by "ACTUALL GLASS" size, this means a 3/0 x3/0 , the LITE size, forget RO.
Quadruple check and then do it again, more than one of us got sideswiped by Manufactures Specs. Vs. Call outs in prints.
I think you either need to size windows by the RO or find out exactly how much bigger the RO should be for a window of a given size.
Tell your supplier that you need the numbers AND a manufacturers drawing so you can check up yourself. This is not something you want to screw up if you can avoid it.
Jon Blakemore
RappahannockINC.com Fredericksburg, VA
Have your supplier come out and show you what "net" means. You are buying the windows from him after all. I'd think he would want to help out.
Matt
Your supplier has data sheets for the windows. Those will show all manner of dimensions.
Rough opening is all you need. Get a catalog of what you are trying to buy from them and check the rough opening size of the window, door, etc. of what you want to install. Net Window Dimension? (Counter guy needs some retraining to give you that)
Order 15 windows "netting" 417 sqft.
That is a one line order.
SamT
LOL,,,,,,,,,yeah but 73% have to be tempered glass cuz 54% are 23% above the below code allowed 12% rule in fugmestan, USA.
'net window dimension', which to my understanding is the same as the finished opening. Am I correct here?
They're not the same. The "finished opening" is the opening into which the window will fit. "Net window dimension" is the actual overall size (width x height) of the window itself.
"Net" size is also known as OSM - outside measure, but I think this is an older term.
So in your case, you should specify the net dimension (aka OSM) to your sales person. Be sure to allow a little wiggle room -- maybe an 1/8" or possibly more, to allow for imperfections in the opening, etc.
As the installer, YOU are in the best position to specify the net window size, because you're the only one who has actually measured the opening and are therefore aware of possible pitfalls -- like opposing sides being skew to one another, a racked opening, etc. A salesperson would just have to make a guess regarding this, which is not the best approach.
Edited 8/10/2007 8:48 pm ET by Ragnar17
Thanks, that helps alot!
I always ordered windows buy their nominal size and had the dealer tell me the net size or the RO size, then framed to match. That way I was getting a standard (cheaper) window than having to pay for one custom sized to my nonstandard opening.
That was of course in new construction. In remodeling I told the dealer the RO and asked for a standard window to fit.
It sounds like your dealer wants you to know all his available sizes before you order from him since standard Net Size varies from manufacturer to manufacturer. OR, he's $upplying cu$tom made window$.
SamT