How I got here and how to move forward.

I just renewed my membership and have never posted a question or even introduced myself. My name is Dwight and I’m finally nearing completion on a project which has consumed most of the last 10 years of my life. Here’s the kicker, it’s not even a house! My “wife” owns a house near Madison, WI, which is climate zone 6B according to your map. It’s a very small log home and she works from home, so when she bought it I told her I would need to build a place to make noise (I’m an amateur/semi-pro musician). I’m also a mason (now retired) who also did a lot of side job handyman work over the years so I told her I could do all the work myself and build it cheap. Well I was wrong on both counts. While I have been able to do a lot (maybe most) of the work myself, the only part that was cheap was, arguably, the masonry.
My personal music studio, as the architect I hired (thought I could draw it myself using SketchUp, one of my early time consuming mistakes) insisted we call it to avoid zoning issues (had plenty of those anyway) is 24′ x 20′ CMU building with a walkout lower “storage” level and the main floor studio. Lower level is 12″ CMU with 2″ Tuff-n-Dri insulation drainage board on the 3 buried walls (walk out wall not yet insulated). The upper level is 8″ CMU’s which are filled with sand for soundproofing. The studio floor is hollow core concrete plank. Both floors will have in-floor radiant heat (installed by my son-in-law an HVAC contractor. The roof is unvented 10″ SIP’s over timber framing. So with all that concrete (not to mention the XPS that will be on both floors) what am I doing on a green building site?
The “short answer” is many times as I web searched various questions, the best answers came from this site. One of those prompted a major footing adjustment which I’ll go into at another time as this post is too long already.
So…a question. I’m currently window shopping. There are 6 in the studio at my wife’s insistence (not great for soundproofing). There is some overlap between insulating for energy efficiency and soundproofing, but they aren’t the same. I’m leaning towards double panes with different glass thicknesses and as large an airspace as possible. But I’m really struggling with frame material and as has been noted on this site repeatedly window manufacturers aren’t great at divulging performance numbers. STC for whole assemblies seems particularly difficult to find. Any and all thoughts welcome. Sorry for the length!
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Replies
You can be a bit greener, and also get a bit more performance in many/most cases, by using polyiso instead of XPS. Rigid foam is really your best option to insulate masonry walls such as you have here.
Most window manufacturers do not specifically target sound reduction applications, so you don't see STC numbers the same way you see the performance numbers for things like SHGC and visual transmission (VT). There are two commonly used glazing assemblies for sound reduction: the most basic is to use different thicknesses of glass for either side of an IGU, such as 1/8" and 1/4". The different thickness have different resonances, so you tend to avoid have any specific frequency range that comes through a lot more than others. A big step up is to go to laminated glass, which is two pieces of glass with a piece of plastic bonded between them. The best sound reducing windows will use laminated glass like this. Laminated glass has a distrinctive "thud" sound when you knock on it, it doesn't have the sharp sound you get when you knock on regular glass. I would check with your window manufacturers about getting IGUs that have one or both panes made from laminated glass.
Note that triple pane windows are a LITTLE better than double pane for cutting down on sound, but that's not really what they are for. Laminated glass will be far, far more effective than a third pane for sound reduction.
Bill
Bill,
That's interesting about the laminated glass & differing glass thicknesses doing more to cut down on sound transmission than regular triple pane. I did not know that - thanks for the informative post! Is there a quick explanation for why laminated glass is so much more effective at reducing sound transmission? (if not no worries - it'd likely go over my head anyway)
Paul
The plastic layer acts to damp the vibrations, so you don't have one piece of homogeneous material. That's basically why laminated glass is so much better for sound dampenening. As an example, the glass in airport terminals is usually a two panes of laminated glass, because they need to cut down on the noise of the airplanes that would otherwise be very loud inside the terminal.
Bill
Bill,
If you read my post again, the xps is going on the floors. In the basement below the slab pour and upstairs on the hollow core which will get a 1 1/2" lightweight pour. On both cases the XPS is preferred by s-i-l for stapling his tubing. I also mentioned the differing glass thickness, as my research suggests performance close to laminate at much lower cost.
What is the reason for in floor heating? Most people think it's going to improve comfort, and in most cases it won't. If your building is well insulated and air sealed, the temperature of the floor will be low enough that it is imperceptible it's even heated. There's a couple of good reasons not to do in floor heating in a modern building. It's a much higher initial cost compared to other options, and it's more expensive to run. It also has more points of potential failure.
Trevor,
Thanks. The reason is my son-in-law will do at cost and it will be very quiet.
Dwight,
Architecturally that building has some very nice bones. I hope there is roof top insulation above the sheathing as it would be a shame to fill in any of the cavities between the framing members.
We have a very knowledgeable poster, Oberon, whose expertise is glazing. Hopefully he will see this and weigh in on your question.
Malcolm,
Thanks the roof panels are 10" SIPS as I mentioned. The inside will have soundcore drywall attached to the SIPS with green glue damping compound in between. There's actually a 3/4" space between the timberframe and the SIP, which will allow me to slide the drywall in place without covering any of the framing.
Dwight,
Sorry, I missed that - and that's great news. It looks like it is going be a very nice space to spend time in.
Malcolm,
No worries, my post was pretty long winded. Easy to miss things when I tried to cover so much background ground. Thanks for the responses. I'll have more questions in the near future and I'll strive for greater brevity with those.
Pella has a good breakdown of window sound transmission, though Bill has covered it pretty well. I am not sure about the assertion that triple pane is only a little better (I would like to see published numbers) but everything else is pretty spot on. That being said pella does have packages that are targeted at sound reduction, and I bet if you contacted them directly they would have numbers and data to help inform your decision.
https://www.pella.com/professionals/windows/how-to-choose-soundproof-windows/
freyr,
Thanks for the link. It doesn't tell me much I haven't read before. Pella, does seem to provide a little more data then many manufacturers, as does Anderson. They both seem on the pricier end of things, however. So far no one has address the frame aspect of my question. Will wood frames always outperform a well built vinyl frame? Is the cost difference worth the performance difference? My current understanding is, with vinyl frames it's all about the number of air chambers in the frame. I've also read the foam filled option is a total waste of money, agree? Since my final wall will be very thick (14"+), and the windows will be installed on the inner edge of the masonry (roughly mid-wall), and there be some rigid foam on the jambs inside and out (for thermal bridging), the frames won't be all that visible. I hate to spend money on wood I won't see, unless I have to.
I would do fiberglass triple pane with as much other sound attenuation attributes you can afford. This gives you longevity, energy efficiency, and sound reduction. I would recommend you go touch and operate as many manufactures windows you can. Filter by manufacter that can accomadate custom igu, triple pane, and either fiberglass or high end pvc.
If you install cheap windows in the space you are proposing you will regret it in 5-10 years. Shift the money from somewhere else in the build that is easily replaced in future if needed.
If you are doing a colored frame make sure you pay attention to how the finishes look, and see if you can find a dyed frame material. There is a big difference in vinyl and fiberglass paint finishes from manufacturer to manufacturer. Fiberglass, to my knowledge, is harder to paint.
Lastly, make sure they are very air tight, air seal with liquid flash at least on inside.
freyr_design,
Thanks again, hands on investigation of many windows is good advice and something I'm trying to do right now. I'm not looking for cheap windows, but to quote Snow_to_Sand (posted below) "good and affordable" ones. Money that could be shifted already has been, to the hollow core floor plank and the SIP's neither of which was part of the original plan.
When I found out how much more, colored frames were, I resolved to paint them myself. I'm a very experienced painter (including priming difficult surfaces) and with the very thick walls and 3' overhangs, the frames won't see much weather or sun, or be all that visible. They'll be painted a dark brown to match the stain on our log home and the log siding which will clad 2 of the exterior walls of the studio. I know dark colors can be a problem with frames, particularly vinyl, but the building gets very little sun and the windows even less as I explained.
My years as mason taught me a great deal about air sealing. The liquid flashing is a good idea.
Sometimes you can't get dual pane windows with wide spacing, but you can get triples. In that case the triple will be significantly quieter espeically if you can get laminated glass.
Noticed a backyard studio around here used what looks like cheap vinyl windows (could be vinyl plus storms, hard to see), one near outside and one on the inside of the thick walls. Might be a budget way to get better soundproofing. I could see it having issues with condensation between the two windows, so make sure to add some small vent gaps to the outside.
Akos,
Thanks for the reply. Spending more money on the glass package and less on frames, seems to make sense to me. Especially since they'll be buried in a very thick wall and partially covered by foam on both inside and outside jambs. I looked at this site which makes storm windows for soundproofing but they're just as expensive as primary windows, so no savings there.
https://www.soundproofwindows.com/storm-windows/
https://www.pressglass.us/market-offering/insulated-units/acoustic-insulated-units/
has a lot of options for stc values. you might have a hard time finding windows that will support the 1.5-2.3" IGUs they have listed... or finding a window company that can/will source such a thing. my windows support a 1.7" IGU but the widow manufacture could only find me 1.5".
https://d5ofx1dg93v3j.cloudfront.net/wp-content/uploads/2023/03/23164709/TGG_V3.0_Final_6-15-2021.pdf
page 52 has some stc values from cardinal.
i did a mix of 7mm laminated + 4mm tempered with a 1" OA IGU, and some with 2x 7mm lam + 4mm center in a 1.5" OA IGU.
its pretty common for me to open a window just to hear a dog barking that i 100% could not hear prior to that.
for the most part i can't have much of a conversation with anyone outside.
this also isn't very scientific, but some dogs were barking and i live like 1/4 mile from a 4 lane ~50 mph street with a lot of traffic. pretty much have direct line of sight -- despite how the video looks.
https://i.imgur.com/oWfklhc.mp4 ... watch with sound on.
kinda sucks because i will never have a point of reference with 2x annealed or 3x annealed, but at least its quiet.
cs55,
Thanks, that's a lot for this old brain to unpack. I'll have to take it in small chunks. What window manufacturer did you go with? What frame material, and if you don't mind my asking, what was the price per window in the end? Sounds like your result was pretty effective
yea its overly confusing.
just went with vinyl, generic tilt and turn windows -- gealan s8000, about as cheap as you're going to get.
https://i.imgur.com/MhMwJub.png
only quotes i could find with annealed glass, but i know for the 36x60 windows, swapping 1 pane of annealed to 7mm laminated added about $150-200.
windows out of europe are a bit cheaper per window, but more in shipping.
The National Fenestration Rating Council seems to have changed their old searchable database site for the worse. Maybe I'm being optimistic misremembering there might have been anything about STC there.
For what it's worth, just jumping in to say that —closer and probably cheaper than Europe— I got a good and affordable triple-pane fiberglass window manufactured by Fibertec (Canada) a dozen or so years ago that performed very well for me. As someone with similar interests to yours, I wish I could tell you anything useful and data-driven about its sound attenuation, but maybe the company itself can. They appear to still exist.
Snow_to_Sand,
Thanks, good and affordable is definitely what I'm looking for. I will take a look at Fibertec.
tilt and turns only get crazy in pricing when you want wood aluminum clad, very nice aluminum, or wood. fiberglass does cost more than vinyl, but it isn't going to be too crazy. that goes for every window, though.
as long as you install any window incredibly well and try to stick with a casement or tilt and turn, i think you will be pretty happy.
if you can afford laminated glass, then great. if not, do what you can.