Hello,

I am in the process of measuring for new replacement windows and have run into a puzzling situation. Background info: I will be replacing 13 original double hung wooden windows from a house built in 1977. Windows appear to be standard sizing but here is the issue.
- Window #1 appears to be a standard RO of 28X38 sized window. Measuring on outside brickmold I find exact measurements of 27¾ X 37 ¼. This would be good news as I see that this is a stock sized window.
- My problem occurs when I measure from the inside. When I measure from both ‘interior stops’ I only measure 27 ½.

Thinking I must be missing something I then removed the interior stops on both sides to get a better look and realized that the window tracks are recessed approx. another 1/4'” on each side and this is why my measurements aren’t adding up.

So long story short:
1. Why won’t my measurements add up to the 27 ¾ even when the stops molding are removed? Was the trim originally installed incorrectly?

2. When ordering the new replacements it would be great to go with the original stock sizes but will I have to go with a slightly smaller measurement?

Thanks for any input!

 

When advertising for replacement windows, the manufacturer will sometimes use rounded numbers to list their windows. So a 28 x 38 may very well be less in either direction so it will fit in an original 28x38 opening. It is always best to get accurate measurements on the replacements before you order them. Measure in 3 places in both width and height of the window opening from the flat against the frame, not on top of the stop, since your window will fit against the stop, not go over it. Use the smallest number when ordering your windows.

 

Thanks for the response. Looking at the specs I can see that the actual window ordered will be slightly smaller than the RO. My concern is that with both stops removed I still can't get a true measurement from jamb to jamb as the area is still recessed. It almost seems like the window stop was installed and THEN the window molding over this. Are their some cases where you also have to remove the actual window trim to get full access?

 

There are many times when it's preferable to install replacement windows from the outside, by cutting off the exterior blind stop with a reciprocating saw. (usually the exterior is professionally clad with aluminum trim coil when this is done, because of the damage the saw does to the exterior trim.) It's quite common to have an interior stop that goes behind the casing. When we run into that, we'll install the windows from the outside 100% of the time rather than remove the casing and stop. You "could" attempt to remove the casing and stop, but be aware that anytime you remove the trim, it's likely the trim will be damaged even if you try to be careful. Obviously this is more critical with trim that is stained and varnished than with wood that is painted, since painted wood can always be caulked and repainted.

The larger measurement on the outside vs inside is usually due to an 1/8" reveal on both sides where the brickmould is nailed to the jamb.

 

Good to know because after looking at many examples of how to measure for windows all show the interior stop nicely nailed over the casing so that when taken off you have full access. No where have I seen a situation where the stop is covered up partially by the casing but this does makes sense for my situation.

For exterior access I have the metal storm window which I will first remove and it looks like my exterior stop is all wood (no aluminum trim coil visible). I would I simply be able to remove this piece / Install the new window and then put the wood stop back into place?

 

On most windows, that exterior blind stop is a wide piece (like a 1x2) that is nailed onto the exterior side of the jamb, and is covered up by the exterior face trim. (similar to the way the interior stop is covered up by the interior casing). That's why I mentioned that we usually cut the exterior stop off (removing just the part that protrudes out 1/2") with a reciprocating saw.

So it's not exactly a matter of "simply" removing the piece, and replacing it. For a DIY'er that isn't an expert with a reciprocating saw, and is planning on recaulking and repainting the exterior trim (not cladding it), you will probably have to remove the exterior face trim from the top and sides, then remove the blind stop, then install the window, and reinstall the parts in reverse order.

 

Great info - I appreciate it all. I will take off a storm window to further explore the setup.

One last question is this. Now that I have the exact measurements of the window many people have said that I should subtract 1/4 from my measurements. Since the window size is stock subtracting 1/4 would require me to now 'special order' the windows. How important is it to subtract an additional 1/4?

 

Give whoever you order or buy from, your "opening" size. The windows will be sized to fit the opening. If the 'stock" windows are 1/4" smaller in width, then you should be fine.
Replacment windows come with an expander for the top, that will fill between 1/2" - 3/4".