Actual size of new const. window frame??

toolingaround · 10-20-2010, 11:18 PM

My rough window opening size (stud to stud/header) is exactly 31 1/8 X 56". I have heard and read that Anderson adds 1" to their "rough" opening size...is that true?

In other words would a window Series 200 RO of 31 1/2 X 56 1/2" still fit in my window opening? or a Series 400 RO of 30 1/8" X 57"?

Its very very close that Im trying to decide. The HD guy says it wont fit but Ive heard otherwise online in some forums that the stated RO by andersen is very liberal? I know I have to factor in the flashing tape/wrap and that.

Otherwise, I would have to somehow reduce the opening (Shaving?) or going down 4" in size and building up with extra 2X's. Ordering custom or opening up my walls is not where I want to go, not yet.

Thanks for any answers!

**kwikfishron** · 10-21-2010, 06:14 AM

Typically when you use your RO measurements for ordering a window the window you receive will be ½” under your RO measurement. In other words if you order for a RO of 48”x48” the window will be 47 ½”x 47 ½”.

I only order using RO numbers in new construction with window replacements I always order “Net Frame”. When you order net frame instead of RO the numbers you give will be the exact size of window you get.

Just Bill · 10-21-2010, 07:12 AM

What he said for replacement windows. You can supply the manufacturer with make size(your dimensions), or opening size and they will make 1/2 less. Check Andersens catalog for actual window frame size, and RO requirements. I don't think their 200 series are available in custom sizes.

Ron6519 · 10-21-2010, 08:13 AM

There's no reason to guess at the exact Andersen window size as it's published on their website. They will have RO dimensions, actual window dimensions and glass dimensions.
The 200 series is a lower end window. If you're staying in the house, go for the 400 series.
Ron

toolingaround · 10-21-2010, 12:31 PM

I see what you mean now- I get it now by looking at the size charts.

It looks like I do need to just go down the next size which is smaller horizontally by 3-4". Hopefully this change by 1.5-2" on each side will not require me to have to rip new exterior trim boards, otherwise the wider trim may look funny.

RE: Replacement windows- thank you for the tips..I much prefer the full scale new windows, as I've heard that you don't get quite as good of a seal with the replacement window frames, and some of my exisiting window frames are not in great shape due to some water leakage over 60 years.

Thanks for all the input!

cumak · 10-22-2010, 11:59 PM

Based on the RO dimensions in your original post, it sounds like the problem is the RO height, not the RO width. Is that correct?

If the RO is the correct width, and you just need an extra inch or so of height, you might be able to lower the sill plate a bit. There's no harm in messing with it because it's not structural. It's only supporting the window.

My windows were framed with a double 2x4 for the sill plate, and I think that's pretty common. If you have something similar, I think you could simply remove the top 2x4 from the sill to give yourself an extra 1.5" of height. Interior and exterior finish work wouldn't be to bad, probably easier than if you went with a smaller window and had to get creative with trim. Plus, you wouldn't lose 4" of viewing space.