Wall insulation proyect... advice is welcome!

Hi Guys! My first post on this great forum... i´m about to start my home studio, so this is my first question (and there will be more! :wink: )... I have no much money, so i came up with this basic structure for walls treatment (recording room)... i will record drums, so i need a cheap way to insulate the room... My father works with wood, so i can get as much as i want... If i´m able to seal the wood structure, creating a 10 cm area of air tight, would this be enough? Any comments are very welcome..! Thanks! J.

Welcome. Before we can start there are a few typical questions. Where are you in the world? What are the dimensions of the room. Please do a search on triple leaf walls. Have you read the links in the "REFERENCE AREA - Useful threads" sticky? What are the existing floors, ceiling, doors, and HVAC like?

Hi z60611! Here´s my situation... the studio will be in Buenos Aires, Argentina. The studio width is 2,4m, but i have to decide the length (btw, there´s another question i have... wich length is preferred for that width). As i have to build the recording room, i think just 1 door -to control room-, no windows, and the ceramics floor that the house have (obviously i will treat it). I have a preliminar layout for my control room, and as soon as i decide the studio length, i can complete it and show it to u guys... I do read a lot, but sometimes i get a little confused traying to translate some specific terms... I´m trying to prepair things onebyone, that´s why i made the question about the walls, obviously when i came up my the "master plan" i would like to share it and get some feedback... but i wanna have some points cleared to continue... There´s any way to improve the insulation with some basic method like the one i show..? Thanks again!

Hi Julian, and welcome; if you could take just a minute and update your profile to show Buenos Aires as your location, people won't have to ask in future questions - thanks... In order to answer your room size questions, we also need to know the height of the room - acoustics is a 3-dimensional thing, so this matters a LOT. Also need to know the construction of the solid part of your drawing - is this a solid concrete wall, hollow blocks, bricks, what? (this goes back to Z's question on triple leaf walls) Another thing; is this room to be on the ground floor or not? And if not, we need details of the floor construction. A general idea of your budget would also be helpful. To get the best results you can, you will need to give as many details of EVERYTHING you possibly can; that way, we know more about your situation and can give advice that fits your situation better. Again, welcome - as you can see, this may take a few posts but there are plenty of helpful people to work with you... Steve

Okey, here i go... the walls are made of bricks and the room is in the terrace of my new house... In fact, 2 walls of the room are undone yet (so i can make them whatever i want). I had the control room, and i have to build 2 more walls to make my recording (i guess it will be 4mts length, 2,4 mts width). About my budget, i realized that i can not afford the "room within a room", no at least making 4 new bricks walls... But i have enough money to buy supplies. The floor raises from 8 to 11 feets (wood and roofing)... My design shown was my approach to the best insulation i came up with... At least without constructing a new room inside the other one... Thanks guys, you´re great!

OK, Julian, so you intend to make the NEW walls the same as your drawing, with brick outside and the insulated wood frame with gypsum panels inside? What can you tell me about the wood you've shown on the frame behind the inside gypsum panel? How thick, is it plywood, MDF, particle board, sawn lumber, ?? Also, are your existing brick walls open on both sides, or have they been "rendered" (coated with 1/2" of mortar over the bricks)? Your 2.4m x 4m size looks like it will be OK with that ceiling height, but you will get better sound proofing if you can render both sides of your bricks and then put both of those layers of gypsum on the INSIDE of the wood frame, making SURE that the frame is NOT touching the bricks directly... Steve

Yes KF, the idea is to build the walls and attach that wood frame... they are brick walls and are coated on both sides... The wood was nothing special really, i mean i have to buy it, so if u can help me choose one kind of wood, it would be great... BTW, i made a mistake! (sorry!) the actual size of the room is 2,9mtsx4mts. The design was a simple idea close to my possibilities, but any change is posible... so, do u think is a good idea this design: brick wall coated, 2 layers of gypsum and the wood frame with insulation and taking care to keep it separate from the wall? Thanks a million times...

Yeah, that's exactly what you need; that, and a ceiling/roof plan that will continue your 2-leaf sound barrier over your head; If you can give me an idea of what kind/size wood is available to you, and arrange them in order from cheap to expensive, I'll try to recommend what would be best (and cheapest) Bricks aren't a good ceiling material, but you still need high mass there; you need to find out what kind of materials/prices are available for the ceiling. In my area, gypsum wallboard is very cheap and has good mass for this - if more strength (support) is needed, or better impact resistance, then OSB, (Oriented Strand Board) or plywood may be required - wood frames also need to be stronger/wider for ceilings, so you'll need to find a source of those. Wider rooms are better, so the 2.9 meters is better; it will take probably one size bigger wood for a ceiling frame though; although with less than 3 meters across the tops of the walls, you would not need more than 2x8 joists on 24 inch spacing; possibly even 2x6 lumber would work. If your ceiling joists must run the long way instead of the short way, then 2x8's would be minimum. HOpe this helps... Steve

Thanks KF (i cant get tired of saying that! :wink: )... my father is a carpenter, so i do have access to different wood at very low prices... i will choose the better for this project, i can save money on woods, so no problem about costs... The roof is not bricks, is wood and roofing ( 8 to 11 feets)... and the gypsum is cheap here too... so, i was thinking in some hangers and a gympsum ceiling. Two more things... the wood frame can be nailed or screwed to the floor? -to avoid the contact with walls- And finally, to break parallels and have a good sounding room, can i use the John´s DIY Absorvers, Bass Traps and difusors for a recording room..?

I'm glad gypsum is reasonable there; it will make things much easier. Before you get too excited, we need to make sure you understand the basics of sound isolation - here is a VERY simplified drawing - http://www.johnlsayers.com/phpBB2/download.php?id=3231 And you should also read through at least this thread http://www.johnlsayers.com/phpBB2/viewtopic.php?t=598 It is REALLY important that you understand some of the things that will cause you to be unhappy with your room; so please read the above carefully, and make sure you understand what a 2-leaf wall or ceiling is, and how to get it. Then, if you can do a sketch of what you intend to do and post it here, we can talk about it til you know what and how to do it without making mistakes. You can NOT be too careful here; one thing in the wrong place (or in the wrong order) can really mess things up for you... Steve

Ok, here´s my basic idea. I read the thread... and that´s my approach to insulation. I realize that fiberglass used by John (on the pics of LDQ studio ) is pinky... is that rigid fiberglas? The one i know is more like green... Again, thanks!

Julian, your wall plan looks fine; if your stuff is kind of green, it's likely to be mineral wool which is also good for sound walls. The rigid fiberglass is generally a pale yellow, but since Owens Corning uses the slogan, "Get Pink", a lot of their products are made that color. All these products will work well for wall insulation; if a 600mm x 1200mm piece that is 50mm thick weighs 1.8 kG, it's the right density for your application; you want something close to 48 kG/cu.M density. For 100mm thickness, of course a slab 600 x 1200 should weigh 3.6 kG... Steve

I´m glad KnightFly! As soon as i have the walls done i´ll let you know how things work... As soon as i have the complete "master plan" i´ll share to have some feedback. Man, maybe you don´t know how much are u helping we all! God Bless!

Ok, let´s get graphical... The first one or the second one?

knightfly wrote:

Julian, your wall plan looks fine;Steve

Hello guys, Steve, I'm not sure if I'm missreading Julian's wall plan, but it seems to me as if he's having plywood on one side and gypsum on the other side of the stud wall, which is, together with his brick wall, creating a triple leaf system?? :? Or am I missreading it? Sorry for jumping in just wanted to make sure Julian's not going in the wrong direction.. :) cheers

Hey Sen, Thanks for the advice! I wanna hear KF opinion, but thank you anyway!

Sure mate he's the oneyou should listen to, not me! :) Anyway, was I right in my interpretation of your plan?Do you actually have the plywood on one and gypsum on the other side? cheers

Sorry for the delay, my schedule often gets in the way of things I'd rather be doing - Sen, good catch - I apparently thought the plywood was against the brick or something, thanks for calling it - Julian, Sen's right on the money. If there is an air gap between the bricks and the rest of the construction, then only ONE side of the wood frame should have any paneling on it - As to which bricks, I would go with the solid ones - too many problems figuring out what will happen with all those air pockets. To review, you want two masses separated by air/insulation, the more insulation the better - one of these masses will be your brick, so you only want one other place where there is mass. This can be several layers but NO MORE AIR GAPS. Not even really small ones. Things that will help isolation - more mass in either or both leaf. Thicker brick or more layers of gypsum or both. Wider air gap, up to a foot (300mm) - Heavier insulation, up to about 60 kG/M^3. Hope that helped... Steve

Thanks guys! I already removed the plywood from my layout! You´re such a wonderful team!

Hey guys! Do u think that i can improve my STC rating by adding a RC to the frame? Thanks! J.

Hello Julian, Including the RC into the construction of the wall that you have detailed in your plan we saw, will not improve your STC.It will only be a waste of money and effort. Your stud frame is already decoupled from your outer wall, so you're fine! :) Unless you're planning on connecting the stud wall to the brick? wall for structural reasons.In that case you would benefit from the RC as that would help decouple your wallboard from the frame and outer wall. hope this helps cheers

Hey Sen! Thanks to KF i found the incredible site of USG, and checking his walls insulation projects i thought that the one shown below was the better for me... I know that i can not make it exactly that way beacuase i already have a brick wall and i don´t want a triple leaf wall, but i was wondering if i can use this model but taking the back gypsum panel and putting it in front of the frame... (i mean to layers of gypsum on one side, none on the other). Let me know what you think... btw, i don´t want to connect the frame to the wall, not al all! :)

Hello Julian, Yeah that's fine, your theory of mass-air-mass is correct.You want to take the layer off the back of the frame and attach it to the front....that's all good.The more layers you have (more mass) the better. But, you don't need the RC-1 pictured in your post, because you're not connecting the stud wall with the brick wall. You would use that method if such a wall (like in that picture) was the ONLY wall between two spaces you want to isolate!In that respect the Rc would help you. let us know if it's clear enough :) cheers mate

Thanks Sen! I understood your point... :wink: Which is the best way to "attach" the wool to the frame? Should i glue the gypsum boards to the frame or use screws? Thanks!!!