How about this door idea?

[Brien]

I'm trying to buy a door with a glass upper half. A separate window does not work for me in this situation. The problem is that they don't block much sound. So how about if I buy an exterior door and attach a thick piece of glass to the door in addition to the existing glass. Anyone try this? How thick? Laminated or solid glass? Any other ideas? Thanks, Brien

[knightfly]

With a single door, there's only so much you can do for sound isolation; same as for walls, it's all about mass-air-mass. More mass, wider air, better iso. Nothing magic about it.

Laminated glass has better damping and better isolation per unit thickness, is more expensive than plain float plate.

If you add glass UP AGAINST the existing glass, it takes double the thickness to improve TL by 5-6 dB. If you can get an air gap between, this helps but it takes nearly 12" air gap to affect the LOW frequencies.

It's MUCH better if you have the space to do a SECOND door and create a sound lock.

If looks aren't critical, cutting a hole in a SOLID core door and putting two glasses, one at each surface, would help.

In any case, SEALS are going to make more difference than almost anything else; ZERO international is one choice, but you're looking at $3-500 for a seal kit; keep in mind though, that a VERY SMALL crack will easily wipe out 10 dB or MORE of isolation, so if you can possibly afford the cost it's worth it.

Have you seen the REFERENCE section's link on door ideas? Steve

[Brien]

Would I be better off getting a solid wood slab and have it cut for window, handle, etc., and add a Zero kit? I worry about the seal on the window and the frame. Would a place like Home Depot be able to do that for me? Thanks, Brien

[knightfly]

Yes, the solid wood slab would be better; but unless the Home Depot in your area is a LOT different than mine, they aren't even CLOSE to being able to modify a door the way you'd want it. This would require something like a custom cabinet shop in order to make a clean, accurate cutout and get the glass installed right.

What would need to be done is to make a cutout that's about 1/2" smaller on each side than your glass panes, then rout a channel all the way around the cutout in the door that will let the glass sit just slightly in from flush, then put gasket material on both sides of the glass and finally add a retainer (like a picture frame) to hold the glass in place and to compress the seal enough.

The space between glasses should be darkened to avoid extra reflections, and you should get some small silicagel packs to place inside; these can be glued onto the bottom edge of the opening between glasses, and some black cloth stapled over them. This will keep the glasses from fogging up.

The retaining frames for the glasses should be attached with several small screws so the glasses can be removed if it's ever necessary.

Now that you know what's involved, it should be clear that this isn't a job for Home Depot, right?

BTW, here's zero's sound control page -

http://zerointernational.com/benefits/ags.asp

If you like, when I get some time I might be able to do a basic cross-section of a door window insert for you... Steve

[Brien]

I've decided to build the doors myself, with help from a carpenter. What thickness/type of glass do you recommend for two panes per door about an inch apart? I'm looking at some sealing kits from ASI, they run about $150 per door. Any experience with these kits or this company? Thanks for all of the help, Brien

[knightfly]

For a 1-3/4" solid slab door, TL at low frequency would only run around 20-22 dB; to match that, two glasses with 1" air gap between them would need to be at least 1/4" one side and 3/8" the other; increasing this to 3/8 and 1/2 would change the m-a-m resonance from around 125 hZ down to around 100 hZ, but no appreciable change in overall isolation.

If you intend to keep the OUTER glass surfaces flush with the door surface, the difference would be even less because the inner air gap would be reduced by the thicken glass.

I've no experience with ASI - found this

http://www.asidoors.com/pages/cleanseal.asp

but looks like they have nothing for sound control... Steve

[Brien]

Here's the ASI I wa talking about.

http://www.acousticalsurfaces.com/acous ... s.htm?d=42 [/url]

[knightfly]

Thanks, too many companies with the same initials - whenever you ask about a particular thing, including a link makes things less confusing.

Those seals look basically identical to Zero international's version, except over $100 cheaper; tested at Riverbank so that's a good thing. Not sure what's responsible for the price difference, but I'd be a bit leary of them til more info was available.

If you've already been in contact with them, you might ask how their product compares to this -

http://www.zerointernational.com/educat ... sp?page=14

Steve