Studio glass?

[metaljoseph]

I am installing the glass in between my tracking room and control room. I am using three pieces of 1/4" glass. The one on the inside of the tracking room will be angled, the other two will be vertical. My question is how do you put the glass together so no condensation gets between the glass when it gets hot? how do I seal it? Regular caulking?Help.

[knightfly]

First, you do NOT want THREE separate pieces of glass or anything else between two areas - it's mass-air-mass that gives best sound isolation. The only reason to angle a glass is for visual reflection control (glare) and mid-high (sound) reflection control. For both, angling the glass to reflect downward and then putting absorption across the front of the mix desk (toward the window) works well.

The downside of angled glass is that you lessen the distance between inner and outer glass, which can reduce low frequency isolation. Using THREE pieces of glass will VERY NOTICEABLY reduce your low frequency isolation - believe it or not, but leaving one piece OUT of your window will actually HELP rather than hurt.

If your window is part of a true double-framed wall, then the glasses should go close to the same plane as your wallboard layers (as far apart as possible) and you'll improve isolation somewhat by allowing the window cavity to "breathe" into the wall cavity around the window.

If you make sure both pieces of glass are clean and dry before installing and sealing, and you vent the cavity as above, then as long as both rooms are kept at or near the same temperature there will be nothing to condense.

As an "insurance policy", you can install one of the glasses using soft rubber and cleats held in place by screws with finish washers - then, if your situation causes condensation you can easily remove the glass for cleaning, and then add some small bags of silica gel between the glasses -

HTH... Steve

Oh, forgot to mention - glass is roughly 3.5 times as dense as gypsum wallboard, so your 1/4" pieces will almost keep up with two layers of 1/2" wallboard each side of the wall.

[bpape]

If it was me, I'd go thicker with the glass. While mass wise it's up there, the resonant frequency is quite a bit higher and it's also far less supported than drywall on studs every 16 or 24".

Bryan

[ausrock]

Ideally, use laminated glass in preference to "float" glass. Laminated is two thin sheets joined by a membrane and this membrane acts to dampen the resonance within the glass. Using differing thicknesses can be beneficial as the two "windows" will then have differing resonant frequencies.

[knightfly]

All valid comments; the 1/4" glass that was first mentioned is (I'd assumed) what the first poster HAS - it won't quite "keep up" with the "standard" double 5/8 gypsum on each of two separate frames though.

However, even 1/4" float will work fairly well if you can get at least 10-12" separation between the (only TWO) panes.

By all means, if you can afford it (or have to have it) 3/8 laminated glass on one side and 1/2" laminated on the other would be as good as any reasonable wall construction.

Keep in mind that if this is to be a COMMERCIAL venture, you MUST have some type of "safety" glass (either tempered or laminated) anywhere within range of a door... Steve

[metaljoseph]

Thanks guy I appreciate it.

[bpape]

Good point on the wider spacing between the panes Steve.

Bryan

[knightfly]

Thanks Bryan - given two 1/4" panes, spaced 4" apart they will reach about 15 dB at 50 hZ with STC of around 45; move them to 12" apart and you end up with about 22 dB at 50 hZ and an STC of around 50 dB. That's definitely worth looking at... Steve