Replacing cracked or moldy IGU (insulated glass/glazing unit) looks easy good source
 

Our house has 2 windows (vinyl frames) that have mold between the pains and a third that's cracked.

I looked online and replacing the IGU looks pretty easy. Cut the adhesive with a putty knife or utility knife, pull out the 4 strips, scrape the old tape, apply double stick tape, insert new IGU, replace 4 strips.

Any thoughts or advice to expand on the above or keep me from running into any gotchas?

What's the best way to get the measurements to use to order the new IGU? I saw online that they are usually 1" larger than the visible glass (1/2" extra on each side). I think it was also mentioned that there's a pretty standard thickness which I assume could be confirmed by checking the overall thickness of the window or would it be best to pop out the strips and measure?

Any specific recommendations for the tape (or something else)?

Any recommendations on sources for the IGU or guidelines on cost?

I'm shocked, there's usually at least a handful of craftsman and DIY folks that have tackled every job and respond on this sort of thread. You guys must all be out replacing your foggy windows! :D

Steve, best way is to have someone or a pro be responsible for the dimension. Pop out the window (not the frame), go to a glass shop and have them perform the work. Its not expensive but will will have a hole on the side of the house for a week. board it up and enjoy the hot weather.

Same issue here, but no removable trim on either side of the door to get the glass out. Probably have to replace the whole door.

I'd probably take the IGU to the pro, let them measure, and then take it back home to install until the new glass came in.

Ouch! That's a pain!

Look carefully again. The trim is normally on the interior of the door. Paint may have hidden the joint for the trim.

Call your local glass or window people. If they are close by, they should come by, measure, and install the glass once it gets delivered. It isn't hard to do so its should not be more then 50-60 bucks labor to change that out.

OK. I have been expecting either "what, only 3 windows, no, we're too busy and won't make enough money to do just 3 windows" and or, "that'll be $1000."

I'll check around for local-ish shops.

I do this all the time as I'm in the glass industry,it's pretty easy depending on the size of the
glass. On a vinyl window,one side of the frame has a removable vinyl snap bead.The glass unit
is installed from that side.There are various types of snap bead.Most click into the frame into a groove on the bottom.You can pry with a sharp and stiff putty knife at the seam between the snap
bead and the frame pulling the snap bead up.Once you get part of it up,the rest you can usually
remove by hand.From the factory with the frame open a glazing tape is applied to the inside edge
of the frame that the glass hits. Most glazing tape is 1/16 by 3/8 either white or black.It has
an adhesive on on side and a removable liner on the other. The bottom of the IGU usually sits
on two rubber setting blocks spaced in 3 to 4 inches from the outer edges. Most frames will
allow 1/8 inch gap all around between the unit and the frame. So if the overall opening is
24 by 36 the glass unit would normally be 23 3/4 by 35 3/4. The width of the unit usually will
be 1/2 inch to 1 inch. Smaller windows are going to have 1/8 inch glass on either side larger
windows 3/16 to 1/4 inch glass.The spacer bar plus the glass is the overall width.Example,
1/2 inch spacer plus 1/8 inch glass on both sides equals a 3/4 inch unit. Typically I can look
at the spacer bar determine the width and go from there.For you, the best way to determine
the width of the unit is to remove one side of the snap bead and slip a putty knife against the glass and into the frame.You can then with a fine line sharpie mark the putty knife on the outer
edge of the glass and that will give you the thickness of the unit.A one inch unit plus the glazing
tape should be approx. 1 1/16. If I am removing the window,normally I will pop off the 2 vertically
snaps beads then go to the other side of the frame, slip a thin blade putty knife between the
glass and the frame to slice out the older glazing tape.Do all 4 sides. By removing just the two
snap beads you are removing some of the compression on the glass making it easier to slice
the tape,while the other 2 pieces of snap bead will keep the window from falling out.Once you
have sliced the tape you can remove the remaining 2 pieces of snap bead and pull the unit away
from the frame.Once the unit is out putty knife the remaining glazing tape from the frame so
you have a clean surface. Apply new glazing tape,dry fit the new window before pulling
the release liner to make sure it fits correctly. Once the unit hits the tape you are not
going to be able to adjust it.Once the unit is in re attach the snap bead and you are done.
The best way to get accurate glass msm's is to pop some of the snap bead initially and measure
off of the existing unit. Get the those plus the width and you're in business. The variables can
be regular glass or tempered.Also you would need to know if the original windows had a Low E
coating. Suction cups also come in handy. When you are slicing out the glazing tape sometimes
it can help to spray the area with some glass cleaner to help lubricate the area to reduce
friction. A normal size window takes maybe 35 minutes to an hour. Hope this helps.

serene911, thanks lots of good info.

On the top, fixed portion of the window, I see the snap bead inside the house. On the bottom portion, the snap bead is on the outside, but that window tilts in for access to the outside of the window. It's square edged bead. I think our IGU is 5/8-3/4" thick (obviously I'll get an exact measurment before ordering if I don't just take them the glass unit. The visible portion of the glass is 26.5x27, and the outside bead edge measurement is roughly 28x28. I'll end up popping some bead off to get a good measurement.

Another easy way to figure glass size. If your snap bead is 5/8, measure the
daylight, the part you see thru then add 1 '' that should also give you an accurate msm.
If the daylight is 26.5 by 27 the glass size usually would be 27.5 by 28. If the snap bead
is 1/2 inch then the glass would usually be the daylight plus 3/4 inch, so if the daylight
is 26.5 by 27 the glass size would usually be 27 1/4 by 27 3/4. That allows for the normal
1/8 in gap around the perimeter between the glass and the frame. That's pretty normal,
there can be exceptions though. Glass msm's are always width first then height.

I've removed about 15 IGUs. I take a new size window out completely to measure. The first one I took to my local glass dealer. I measured 5/8" thickness. He said 7/16". He was right. I get all the vinyl beading from them at $6 for 12'.

Good to know.
THanks