PLEASE! Help me reduce noise leakage in my studio!!!

jeronimo · Post by **jeronimo** » Sat Apr 24, 2004 6:44 am

Ok guys, take a look on the picture attached it shows a "side" cut of my live room.
It is built w/ regular hollow brick walls (around 15cm thick each), the walls are 10cms away. The external wall reaches a ceiling made w/ concrete studs and bricks (I don't know how u call this type of construction), the same way is the floor. Under my floor is my mom's place, and the thing is... when there is drums or a 4x12 beign played on the studio, there is too much noise on the floor below. I built a raiser for the drum kit, but it's not enought. The inner walls of the room share the same floor as the external walls... so there is some sound transmition going on between floor and internal walls and external walls.
What should I do? I'm thinking of building some hardwood floor over a thick rubber... don't know what kind yet.
What do you guys suggest?

Post by **Aaronw** » Sat Apr 24, 2004 7:23 am

What do you have for insulation in the ceiling of your mom's place? You may need to add insulation if there isn't any. (Which means you may have to pull down existing ceiling??)

Is the drum riser you built floating? Is it insulated?

Aaron

jeronimo · Post by **jeronimo** » Sun Apr 25, 2004 4:46 am

There is no insulations on her ceiling... what do you think of drywall w/ rockwool?

The riser is built like this (from the ground up):carpet, rubber, studs, rubber, 15mm plywood (w/ rockwool glued to the back) and carpet.

Ideas?

knightfly · Post by **knightfly** » Mon Apr 26, 2004 4:20 am

Geronimo, there is no fix for your situation that does not require more construction - here's what I think is happening - although you didn't specify the construction of your floor (mom's ceiling", your inner walls are resting directly on the floor - that floor isn't built for sound isolation, so anything that vibrates the inner wall will transfer to the floor, which is effectively your mom's ceiling (minus losses thru the mass) - all you say about your room's ceiling is that it's built the same way as the floor - but you don't describe the floor, so that means nothing.

Basically, you would need to completely float a room inside what you already have if you want more isolation - you could float a floor (another can of worms most likely) then mount 2 layers of wallboard (gypsum) on resilient mounts inside your walls, and suspend a gypsum ceiling resiliently under your existing ceiling. Everything well caulked would solve the noise problem.

One problem with doing all that is your existing construction - it's doubtful that your existing floor is strong enough to take the point loading of a floated floor, for one - disregarding this can be FATAL. A possible alternative could be a "semi-floated" floor, where a softer material is used 100% of the floor space and a new floor installed over this - also a possible problem, not knowing what your floor is constructed of.

With flanking noise, ANY structural parts that have hard contact with each other will transmit noise - the ONLY way around that is to either NOT have them touching (a complete re-build usually) or to isolate the inside walls from structure with resilient mounts of some type.

Before I could recommend any specific procedure though, I need a LOT more detail from you on your existing construction, including how you are supporting the weight of those block walls you built around your room... Steve

jeronimo · Post by **jeronimo** » Mon Apr 26, 2004 6:31 am

Kinghtfly, sorry, but I really don't know much about construction stuff in English

As I described my floor is built w/ concrete studs (????) w/ bricks mounted between them and concrete all over it... if you know what I mean... that's how houses are built here in Brasil.

So you think I need to build a room inside my actual room right? Floating the floor won't help at all?

As you can see on the ugly drawing I made, 3 of my external walls are the "main" construction walls, they go from the floor below to my floor, did I make myself clear? My inner walls are built ON my floor, so, my floor is holding the weight of my inner walls. I'll post the floorplans.

Maybe some pics tomorrow will help me here

I didn't understand what do you mean by floating the floor would be another can of worms

Looking foward to hear from you guys!

knightfly · Post by **knightfly** » Mon Apr 26, 2004 10:40 am

It appears that you have hard contact between your walls and the floor - that floor is your mom's ceiling - so any sound that can vibrate your walls is transmitted through the wall and into the floor, which vibrates the floor - since that floor is your mom's ceiling, now her ceiling vibrates.

As long as sound from your rooms has ANY way to reach ANY of your walls, floor, or even YOUR ceiling, this sound will travel through the masonry and re-radiate in ANY room that is structurally connected to the upstairs.

The only way I know to keep this from happening is to completely float the inner walls of your rooms, so that no matter which direction the sound travels in the room, it can ONLY vibrate things that are resiliently mounted, like floor, walls, and ceiling. If you allow ANY solid connection to the rest of the building from inside your rooms, the sound will flank through that solid connection and be heard in the rest of the house.

What I meant by "can of worms" is that before you could even think of floating a floor, you would need to know the structural properties of your existing floor to know if you could safely float a new floor over the existing. Most floated floors use elastomer blocks on a pattern, and the resulting pressure on the sub-floor can be tremendously large. Think of a fat woman wearing high heels - would you want your finger under her heel, considering that the pressure could exceed 1000 pounds per square inch? This is the same principle - the entire weight of the floor and everything ON that floor would be resting on these little resilient blocks spaced every few feet, instead of evenly supported along the surface.

In your case, it sounds like your masonry floors may be strong enough - but I'm NOT going to tell you it's OK to float a floor on that when I don't even know for sure what you have -for that, you need to contact a LOCAL engineer and explain your ideas, and find out how strong your floor is BEFORE you decide to place even MORE stress on it.

It might help if you could post a drawing that shows exactly how your floor is made, like a side view showing where every part of the floor is, and WHAT it is, and what size it is -

Other than that, I'm curious as to why you built non-isolated rooms after hanging out here so much - is there some other way I need to express things so they are more clear, like maybe more pictures/drawings? I'm not trying to get on your case, but if I'm not communicating well enough then others may end up building things that don't work as expected, and THAT really makes me unhappy. So, if you can think of anything I can do that will make things more understandable, please speak up so I can hopefully keep others from having this type of problem... Steve

jeronimo · Post by **jeronimo** » Mon Apr 26, 2004 3:33 pm

No KnightFly, don't worry, I knew EXACTLY what had to be done when we built the place from the ground up!!! Construction took me 7 months and I did the biggest mistake in my life... I DID listen to the engineer... that's what killed me!
On my plans, the floor should have been built floated on fiberglass. So I would have the actual flor + fiberglass + hardwood floor and a room made of drywall standing over this hardwood floor.
But, the engineer told me: "hey, don't worry, u don't need the 2nd layer of "floor", blah, blah, blah"
And I was stupid enought to say: "Ok, if you're telling me this..."
So, now I'm broke, 'cause I spent all my money on the construction and I have to solve this problem...
So I'll probably build another drywall room over some hardwood floor floated over neopreme or something similar and pray to have enought work to pay my debts

Here is a drawing of how my floor is built...

knightfly · Post by **knightfly** » Mon Apr 26, 2004 5:16 pm

"I DID listen to the engineer... that's what killed me!" -

OK, now I know what I'm doing wrong - I'm not giving my "don't listen to local builders" speech nearly often enough...

I've had local drywall contractors (older than me, if you can believe it) tell me that Resilient Channel is USELESS, doesn't work and even makes things worse - I ask them how/where they install it, and (surprise) without exception, they say "over the original drywall, then add a second layer of drywall" - is there ANYONE reading this that can NOT tell me why RC didn't work for them? Oh, and they never even MENTIONED caulk...

Thanks for the diagram, I've never seen that exact type construction before. I'm wondering if those "studs" are pre-stressed concrete joists(BTW, studs are vertical framing members and joists are horizontal) - Any idea of the load bearing specifications? You might still be able to salvage your place if we can find that info -

Oh, and before you take the word of your local "help", you should ask to see some of their work relating to sound rated construction - if you're not impressed, don't listen.

Try to find out what(how much weight) your floor is load rated for - your project may not quite be dead yet... Steve

jeronimo · Post by **jeronimo** » Tue Apr 27, 2004 4:43 am

Ok knightfly, so what I called "studs" supposed to be "joists"?

Cool, so those joists are pre made, joists... I'll see if I can take a picture of an unfinished part of these kind of building...
Do you live in the U.S.? How do you guys build this kind of "floor" over there? I'm just curious.
Ok, I'll send a fax to my local drywall supplyier to have a "quote" on a whole new room

I'll ask the responsible engineer for the aproximate load those floors can handle.
Post back later!!!

jeronimo · Post by **jeronimo** » Wed Apr 28, 2004 10:16 am

Oh boy, I must say I'm depressed...
I just got a quote on the floating floor from some major company here in my hometown in Brazil, and the price was... just... insane.
So, making anything from this company is out of my plans right now. Here is the http://www.rsmanutencoes.com.br/pisos_elevados.htm (link) for the description of the floor... it's in Portuguese but there are some pictures that show how it works.
Ok, so I was taking a look on the SAE reference material, and I realized that the drum raiser I built, has the exact same principle as the example of timber floating floor, BUT I made the raiser w/ 1 ply of 15mm plywood.
So, I'll try to have a quote on building the floor based on this example, have anyone tried this? Any comments?

By the way, I'm still waiting the price quote on the single ply drywall + rockwool walls... this picture shows how it's done

So, do you think knightfly, if I make the floor like SAE examples and put those type of walls over it and the same kind of ceiling (using drywall + rockwool) I would be safe enought (sound leaking wise)?

knightfly · Post by **knightfly** » Wed Apr 28, 2004 9:49 pm

Geronimo, what I need from you before we can even start, is the support capability of your floor as I mentioned earlier - without that, your entire house may come crashing down. I'm NOT kidding -

Also, don't start building complete walls inside what you already have, you will only make things WORSE.

Just so we are clear, are all the walls you show in your complete studio floor plan already built, or just one room, or what? Also, what is the height from your floor to the inside surface of the ceiling?

There is no way I can be your engineer from so far away, but if you get me the above info I'll do what I can to recommend ways out of your problem - just do NOT keep building until I know exactly what you already have, and can think about it for a while... Steve

jeronimo · Post by **jeronimo** » Thu Apr 29, 2004 12:39 pm

Ok knightfly, I got it... all help you can give will be very, very welcome.

Right now, the building is DONE. All the walls on the floorplan are DONE.
I won't be building nothing 'till I get all quotes and stuff... no more money can be lost!!!!!!!!
So, here goes the pics:

jeronimo · Post by **jeronimo** » Thu Apr 29, 2004 12:42 pm

More pics

knightfly · Post by **knightfly** » Tue May 04, 2004 11:20 am

Sooo, Geronimo, the good news is, it looks to me like your floors may be plenty strong enough to support a floated floor - you would still need to use some type of resilient mounting and isolate those inner walls so they don't get as high a sound level, because they will transmit right through to the floor and into the room below.

Have you had a chance to ask about actual live and dead load specifications yet? That would be a lot better than my long-distance guess from a picture... Steve

jeronimo · Post by **jeronimo** » Wed May 05, 2004 1:26 pm

Not yet... I'm trying not to talk to the old engineer... I'm looking for someone else to help me out w/ this specifications

I'll post back!!!