Double-double glazed window for soundproofing?

[Hankhill]

I’m hoping to get a small studio built in place of my shed, using concrete blocks. I’ll soundproof the walls and ceiling with the usual Rockwool type stuff behind MDF panels, but for the window what I had in mind was having two identical off the shelf uPVC windows mounted back to back. Would this work? Also, I plan to use an off the shelf uPVC door, with a second door inside. Will this inside door have to be a heavy fire door or will a standard internal panel door suffice? I'm not seeking soundproof perfection, just somewhere my son can practice drums without annoying the neighbours.

 

[Capriccio]

WINDOW: I cannot be certain but I suspect you will find that 4 panes of glass may not be as effective as 3. I suspect that a uPVC double glazed window may be more effective in partnership with a thick laminated pane rather than a second double glazed unit.

DOOR: Yes, a thick and solid fire door with good seals will be far more effective than a panel door.

Drums are loud. You would do well to buy an SPL (Sound Pressure Level) meter and measure how loud it is near the boundary tom the nearest neighbour's property so that you have some idea as to how much you need to soundproof the shed. There is no point spending lots on unnecessary levels of soundptoofing just as much as spending too little in the vain hope it will be sufficient.

 

[domvac]

I thought you were talking about a double-double Tim Hortons coffee with a glazed donut.......Not soundproof but delicious

 

[RICK FITZPATRICK]

According to Rod Gervais, author of this book:

Amazon.com: Home Recording Studio: Build It Like the Pros (9781435457171): Rod Gervais: Books

For a single TWO LEAF wall assembly comprised of 2x4 wood studs, and two layers of 5/8" drywall on each leaf, with batt insulation, it will take ONE PANE of 1/2" thick glass, and a second pane of 3/4" thick glass, to equal the Transmission loss of the wall assembly.

But here's the REAL DEAL. Weak Link syndrome. If your floor, surrounding wall assembly, and ceiling, do not perform EQUAL to what ever window assembly you are installing, then you are wasting money,time and energy. Even a concrete floor can be a flanking path due to structural transmission of vibrations right under the wall. Same with the ceiling. If there is a common attic to both rooms, unless the ceiling mass in each room is equal to the wall/window assembly, you have a flanking path.

This is why it is important to understand when building isolation assemblies, the whole is only as good as the weakest link. And to understand what TRANSMISSION LOSS ratings mean.

In other words, why install a window assembly with a TL rating of say 55, when the surrounding wall is only rated at 45.

I would suggest you research EXACTLY what your existing iso assemblies are rated at, and any flanking paths, before you define what the Window assembly should be. And frankly, from what I understand, installing any more leafs(panes of glass)than a two leaf window assembly is less than wise. Sure, I've seen Pro studio window installations with as many as SIX panes. However, these are engineered for various building conditions and acoustical/TL targets that are beyond most HR enthusiasts budgets or knowledge and building conditions.

Understand this. When it comes to HIGH PERFORMANCE ISOLATION, low frequency is the enemy. Decoupled Mass is the best weapon of choice for constructing high performance isolation. And the lower the frequency, the more mass it requires. Not only that, but TWO LEAF assemblies(MASS/AIR/MASS ie..MAM) have proved over time to outperform multiple leaf systems.

For instance. There is a studio in Belgium called Galaxy Studios, which the owners defined the original isolation criteria to meet a Transmission Loss of 100db at 30hz. Only two Acousticians in the WORLD, dared to take on the challenge. When all was said and done, every room was a concrete box, floated on massive steel springs, and created a TWO LEAF boundary between every room. INCLUDING THE GLASS..which by the way, were the thickest panes of glass ever manufactured in Europe. If memory serves, these panes were approx. 4" thick and weighed over 11 TONS EACH!! That is what it takes to isolate low frequency sound. PERIOD.

Soooooooooo, the next time someone on this board suggests you can COMPLETELY isolate 100db drums/bass guitars with standard construction iso materials/techniques...well, I got news for them.

 

[RICK FITZPATRICK]

Actually, I just re-read your post, and some thoughts came to mind.

I’m hoping to get a small studio built in place of my shed, using concrete blocks.

I'm not seeking soundproof perfection, just somewhere my son can practice drums without annoying the neighbours.

Well, the key here is TOLERATION. At what point, SPL wise, is acceptable "noise" toleration by the neighbors. 30 db? 40db? 55db?

And how loud does you son play?

And how close are the neighbors in question?

Have you ever had complaints in the past? Have you talked to them to understand what they are hearing?...ie...how loud is it in the neighbors house?

First and foremost, you really need to define what your neighbors are hearing..SPL wise. And as to your choice of building materials, you MAY NOT need to go the concrete block path. But, without any information, it's impossible to say at this point, as distance has a bearing.

Also, is this building going to be used as a Recording Studio or just a practice space? Your post seems to give more weight to the practice use. In reality, there many other considerations for a studio, than just a practice pad. For instance...HVAC/ventilation. Doors. Depending on the required ISO... separate floor pads and decoupled room assemblies..etc etc etc.

It would help if you define a few things here, and give us more info. There are lots of things to consider, especially if you are thinking about concrete block construction. Just the budget for that choice of construction alone suggests you are willing to do what is necessary to..like you put it..."without annoying the neighbours."

You also said..."I'm not seeking soundproof perfection"

Well, first off, there is no such thing as "sound proof". Only levels of Transmission LOSS. When you begin to understand this, it becomes easier to define what level of TL you are trying to attain. And once you do, then you will understand, the ONLY way to actually define it...is to MEASURE what your son is producing, and then determine what a building TL must perform at to meet its target. Sounds simple, right? Well, lets just say you are on a path of enlightenment. Get back to us with some info and we'll try to help you find that path.

fitZ

 

[Hankhill]

Wow, thanks for the detailed response! I’m aware (only from Googling) that “soundproofing” in the true sense is hard if not impossible to achieve. What I’m after is somewhere my son and I can rehearse that is better than the current bedroom. He has an Arbiter Flats drumkit so maybe not as loud as some, and I play bass. I doubt that our respective bands will play full pelt as the “shedio” would only be 3M by 2M.

My hope is that by having a single layer concrete block built shed, with internal soundproofing using Rockwool type tri-layer acoustic material (like this - soundservice.co.uk/acoustic_quilt.html ) behind MDF panels on walls and roof, that it will be sound insulated enough. For the door I planned an off the shelf uPVC door (am I better with a glazed or blank panel?) plus a second heavy fire door mounted inside with a 4" gap.

For the window I understand two uPVC windows back to back may not work well, and the single block wall won't be thick enough anyway to support them. So I'm now thinking maybe just a clip on panel of wood and Rockwool, or perhaps a polystyrene sheet, that we'd just clip over the window when playing. Another thought - I have seen triple glazed off the shelf uPVC windows, I realise these are for thermal not sound insulation, but would they help? Capriccio did say above that “4 panes of glass may not be as effective as 3”.

 

[Capriccio]

Capriccio did say above that “4 panes of glass may not be as effective as 3”.

Sorry, that was vague, misleading and on checking chapter 5 of Rod's book I remember it related only to my rented studio. Rick is correct when he says:

... from what I understand, installing any more leafs(panes of glass)than a two leaf window assembly is less than wise.

Two panes will give you better isolation. Each pane will act like a drum head and have a resonant frequency. You will want two different thicknesses to avoid what is called the coincidence effect, where the two panes are excited together at the same frequency. The window, the door and teh roof need the same mass as the wall in order to provide the same levels of isolation. Anything less and there will be your weak link.

... Arbiter Flats drumkit ... 3M by 2M.

I have these drums and my last room was 3m x 2m so I can envisage exactly what you are up against.

a single layer concrete block built shed

I am not expert enough to know without re-reading books that I haven't the time for right now (it is approaching 3 am and I must go to bed) but I suspect that a single wall will not be enough to give you 60db+ of isolation. It might be all you need but do check first as it would be disheartening to build the shed only to find it fails to isolate the sound sufficiently.

For the door I planned an off the shelf uPVC door (am I better with a glazed or blank panel?) plus a second heavy fire door mounted inside with a 4" gap.

If the mass of the fire door is greater than the wall(s)then a uPVC door may work, otherwise I would suggest any solid woodedn door as it will have more mass.

For the window ... a clip on panel of wood and Rockwool, or perhaps a polystyrene sheet, that we'd just clip over the window when playing.

Polystyrene will do nothing. Rockwool will help with absorption which is a different topic to isolation. It will not improve the performance of a window for stopping noise escaping from the shed.

I haven't mentioned the roof. Are you happy that it will have sufficient mass? Back to Rod's book: he says quite rightly and simply that acoustic isolation is achieved with mass, mass and more mass.

All said, you are on the right track and it sounds like an exciting project.

Goodnight!

 

[Hankhill]

Just to add onto this old thread of mine, I need to order the door pretty quickly. The standard uPVC ones come in various styles, i.e. half glass and half blank white panel, or full glass. I'm assuming that a full length double glazed glass panel will provide slightly better soundproofing than a part glazed and part panelled door, am I right?

 

[RICK FITZPATRICK]

. I'm assuming that a full length double glazed glass panel will provide slightly better soundproofing than a part glazed and part panelled door, am I right?

Actually, it's a moot point.

Back to Rod's book: he says quite rightly and simply that acoustic isolation is achieved with mass, mass and more mass.