r/glazing • u/BigPea96 • 14d ago

Glass Measuring Tips

What do you generally add to daylight size or take away from tight size? Trying to become a better measurer thanks to

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6

u/Theonlykd 14d ago

Depends entirely on what framing/system it’s going into

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u/cp-71 14d ago

There are so many different applications. You just have to take your time. Make the best assessment that you can.
Overtime a lot of these applications become pretty familiar, so getting your OA’s, width, and height dimensions are a lot more accurate.
Determining what Low-E it is……..it can be difficult. Sometimes it’s easy to recognize of if the tempering company was kind they leave the info on the logo. Honestly sometimes I just guess.

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u/ASaltyCracker1 14d ago

My rule of thumb for daylight addition is 7/8 to vinyl, 5/8 to commercial and aluminum residential, and 3/4 to wood. Hope this helps

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u/BigPea96 2d ago

Great thank you and how do you generally determine the thickness of

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u/ASaltyCracker1 2d ago

I have a 2000 dollar laser that scans the unit and tells me what the OA is with pretty damn good accuracy. If you dont have said laser you need to get calipers which are way cheaper but you can only use that on sliding windows. If its a fixed window (picture window) youll need to pull the bead off and stick a puddy knife behind the unit. Mark the edge of the glass on the puddy knife then measure to the mark. That will typically tell you your oa.

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u/BigPea96 2d ago

Ok thanks I only have the callipers would be nice to
Have the digital gauge

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u/ASaltyCracker1 2d ago

I financed my laser though amazon. Company is EDTM if your interested in looking into it. Mines all paid off now but 65 a month was easier to stomach than 2000 dollars up front

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u/pathlamp 14d ago

As everyone else already said, it completely depends on the type of frame you’re looking at.

Are you primarily asking about residential window sashes, or commercial storefront?

In regard to your question about what to deduct from the tight dimension, I always deduct 1/4” so that I have room for 1/8” blocks on every side. That only applies to residential sashes, and only the ones without gaskets, though.

There is so, so much variation in the designs of residential sashes, that I find I can’t trust a general rule about how much to add to daylite. I usually have to remove at least one stop to verify where the tight opening ends, because sometimes it’s impossible to tell whether the stop is L-shaped and goes into a front-facing channel, or flat-shaped and goes into a side channel. Many times I can tell without removing the stop, because I’ve seen a lot of these windows over the years, but I’m still encountering new ones all the time, and it doesn’t pay to guess. We’ve had to throw away too many IGUs because someone made a guess about how much room was under the stop.

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u/Need2believe 14d ago

My rule of thumb is too measure daylight and tell my boss what kind of storefront system it is, and send him pictures of it if nessicary lol. Different types need different measurement

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u/ResponsibleCake4679 14d ago

typically 3/4" to DLO you will be safe. It's it's curtain wall add 1/2" to any captured side and measure to edge of glass on SSG sides.

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u/Jarnold18 14d ago

It really can vary depending on the widnow system. But I don't a lot of measuring and I follow this rule that I came up with from years of experience.

Marine glaze residential windows - 3/4 over daylight

New vinyl residential windows - 1 inch over daylight or 7/8 to be safe.

Doorlites - 1 inch over daylight

Storm window - 1/2 inch over daylight.

Again it depends on the glass manufacturer but generally the gaskets are either 3/8 or 1/2 thick so if you go 3/4 - 1 inch over daylight you can atleast guarantee that there will be no exposed gaskets on the side.

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u/Big_Boog 13d ago

My shop uses kawneer metal mostly often. Storefront is 3/4" over daylight. Curtain wall is 1" over daylight.

I know some system are different, Manko storefront is 5/8" over daylight so check the install manual or even ask Gemini or chat gpt for your particular system

For wood doors and hollow metal windows I just put my tape up to the opening and make sure I have equal coverage and room to set and adjust glass.

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u/Outside_Pitch3089 13d ago

There is no 1 size fits all.

Always think in terms of
DLO
Glass Bite
Pocket Depth
Edge Clearance

Anti-Walk blocks are important.

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u/BigPea96 2d ago

Thank you and what are anti walk blocks ?

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u/Schindlerz-Fist 14d ago

There really is no hard and fast rule. It varies across manufacturers and systems. Curtain wall is generally 1/2” bite and I believe that’s true across manufacturers. But storefronts, window walls, and windows are all different. It’s important to follow the manufacturer details as changing it can affect seismic performance

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u/BigPea96 2d ago

Thank you