John Sayers' Recording Studio Design Forum Archive

Hello everyone!
First of all, I'd like to thank and congratulate the members and mostly the people who run it! It's an amazing thing to share knowledge and help people! Thank you!
I've been searching the forum and all the threads for a while now and I've learned a lot already!

Well, it's now time to ask for help!
I want to build a rehearsal room (for drum practice and a rock band, about 100 - 120 db) in my garage, which is directly under the living room, partially buried, hence the "Garage/basement". The dimensions of the garage are 7,5m(L) x 5,1 (w) x 3,2 (h). I can only use half of the space, because I need to park a car in there as well.
I know the dimensions I have left are not ideal, far from it actually, but that's what I've got...
It's an older house, so it probably has traditional thick brick walls and thick concrete slabs. I rent it, don't own it so I don't really know...
It's a quiet residential area, so I'm not concerned about noise from the outside, but the main concern is to keep the music from leaking out to the street and even into the house, since I share it with two friends.
The walls on the left corner of the garage are not to the outside of the house, they are buried in the ground, so I want to use that side of the place. Maybe the SKP drawing will illustrate better (left and rear walls on the skp drawing). The garage has ceramic floor tiles and also tiles on the walls (up untill 2,0m).

The idea is to use two of the existing underground brick walls (left and rear walls) and build (i'll be doing all the work, with a friend, no contractors) a wood frame, fill it with 50mm 50kg/m3 mineral wool insulation and 12,5mm plaster board inside and outside of the studio. Maybe two layers of 12,5mm drywall on the outside.
I've though about mounting the inner plaster boards in 5 degree angles to break the parallelism, but it was just a guess, I'm not sure if that would do anything...
For the floor, I'd just leave it as it is, and put the drums over a drum riser, to isolate the impact from the floor.
The inner dimensions are 4,2m (could be bigger if necessary) x 2,3m (limited by the pilar and the total width of the garage) x 2,6m (could be higher if necessary).
I plan to use a 9.000 BTU A/C.

The questions for now are:
I'm I going in the right direction with the soundproofing part??
If so, how much soundproofing could I get with it (I guess 60-70db would be ideal)?

The budget I have is around USD 2.000. Not much I know, but for the basic I think it's enough...
Then get one of those portable P.A. systems (probably, the Yamaha Stagepas 400i, what do you think?)
Again, it's only a amateur rock band rehearsal room.

Once the basic construction is resolved, he next step would be to acousticaly treat it, but I thing that'd be another chapter. Or maybe not! hahaha

Here are some SKP pictures to illustrate it a bit better.
Thank you so much!

Hi Henrique, and welcome to the forum!

I want to build a rehearsal room (for drum practice and a rock band, about 100 - 120 db) in my garage, which is directly under the living room,

OK, so you need a LOT of isolation! that's for sure.... This is not going to be easy!...

The walls on the left corner of the garage are not to the outside of the house, they are buried in the ground,

Excellent! That's very good news. So you only need to do the other two sides, and the ceiling, the door, the HVAC, and the electrical.

The garage has ceramic floor tiles and also tiles on the walls (up untill 2,0m).

Also excellent!

a wood frame, fill it with 50mm 50kg/m3 mineral wool insulation and 12,5mm plaster board inside and outside of the studio. Maybe two layers of 12,5mm drywall on the outside.

That would get you about 30 dB of isolation, which is not very much. In order to get the very high levels of isolation that you want, you'll need to do a proper 2-leaf "room-in-a-room" studio. That means building the other two sides of the outer-leaf, but with a lot more mass than you show, then building a completely separate room inside that shell, also massive.

I've though about mounting the inner plaster boards in 5 degree angles to break the parallelism, but it was just a guess, I'm not sure if that would do anything...

Not really. It would look nice, but it wouldn't serve any useful acoustic purpose: And it would be hard to build that.

For the floor, I'd just leave it as it is, and put the drums over a drum riser, to isolate the impact from the floor.

Yep!

The inner dimensions are 4,2m (could be bigger if necessary) x 2,3m (limited by the pilar and the total width of the garage) x 2,6m (could be higher if necessary).

For drums, make it as high as you can, within reason. Drums love airy spacious rooms, and if you want to track your drums, then you need a lot of space above the overhead mics to prevent artifacts from ceiling reflections.

I plan to use a 9.000 BTU A/C.

For Sao Paolo? In summer? With several musicians in there? Hmmmm.... I would suggest going to a 12.000 BTU unit. Maybe even more than that, if you plan to have a lot of amps and other gear in there, and a lot of lights, and a lot of people... There are equations for figuring out how much cooling and dehumidifying capacity you need. Don't guess. But knowing how the climate is in Sao Paolo, I would suggest something bigger than 9.000 BTU.

OK, so that's the cooling, but what about the rest of the HVAC system? I don't see any ventilation on your drawing: no ducts, no vents, no fans, no silencer boxes... You need to do that as well.

I'm I going in the right direction with the soundproofing part??

Not really: You need a high level of isolation, and your plan is not going to do that. You need to do a proper "fully-decoupled two-leaf MSM isolation" system. That's the best way to get high isolation at low cost.

If so, how much soundproofing could I get with it (I guess 60-70db would be ideal)?

Your plan would give you about 30 dB of isolation. A typical home studio gets 40 to 50 dB. Professional studios might get 60 to 70 dB, but that's not so common. It is hard to do,m and expensive.

Each time you go up by ten decibels, you need to block ten times more energy, and it gets ten times harder. So going from 30 to 40 dB means you need to block 10 times more. Going from 30 to 50 means you need to block 10x10=100 times more. Going from 30 to 60 means you need to block 10 x 10 x 10 = one thousand times more. And going from 30 to 60 means you need to block ten thousand times more energy than your current plan. Decibels is a logarithmic scale, so things get very big, very fast as you move up. This is why it is very difficult and very expensive to get 70 dB. You could probably get to 60 dB, if your isolation plan is very very carefully designed, and you build it very, very carefully, and you have a good sized budget. It would be a lot easier to go for 50 dB.

The budget I have is around USD 2.000. Not much I know, but for the basic I think it's enough...

Actually, no it isn't. That's about the cost of the HVAC system, all by itself. 2k would not even be enough to by the materials that you will need for your current plan, and certainly not enough to get 60 dB. Or 50. Or even 40.

Here are some SKP pictures to illustrate it a bit better.

Your framing is incorrect. That would not pass inspection, and would not work for isolation walls. It is not even safe: the ceiling would probably collapse. I would suggest that you do some research on-line on how to frame a structural load-bearing wall, and also look into how ceilings are built safely, taking into account spans, dead loads, live loads, deflections, etc.

But the biggest point is that you cannot get the type of isolation you want from the plan that you have. You need to move up to a proper two-leaf "room-in-a-room" build, with lots of mass on each leaf, a large air gap, and perfect seals.


- Stuart -

Hi Stuart and thank you so much!
And I thought I was going in the right direction here! hahahahaha

OK, so you need a LOT of isolation! that's for sure.... This is not going to be easy!...

Well yes, but on the other hand I probably won't be playing late at night. It's just going to be until say, 9pm, and my roommates are cool enough to tolerate some of it. And the neighbors can't really complain if it's it's not absurdly loud and doesn't go after 10pm.

Excellent! That's very good news. So you only need to do the other two sides, and the ceiling, the door, the HVAC, and the electrical.

Ok, so no need for any additional structures, (wood frames, insulation, plasterboards, etc) there, right!?
Or should I also build the frame, plasterboard? Maybe no need for mineral wool.. What should work best...?
And if I build the drywall there, could it touch the brick wall at all?
OR

Also excellent!

That would get you about 30 dB of isolation, which is not very much. In order to get the very high levels of isolation that you want, you'll need to do a proper 2-leaf "room-in-a-room" studio. That means building the other two sides of the outer-leaf, but with a lot more mass than you show, then building a completely separate room inside that shell, also massive.

More like this...? It'd be almost 19cm thick. Two layers of 12,5mm plasterboard, 5cm rock wool, 5 cm space, 5cm rock wool, one layer of plasterboard.
Would it need insulation on both leaves? If I got it right, in the MSM system, the mineral wool is considered "spring", not mass, right..?

Not really. It would look nice, but it wouldn't serve any useful acoustic purpose: And it would be hard to build that.

Yeah, I figured that it wouldn't make any diference indeed. So no angled walls!

For the floor, I'd just leave it as it is, and put the drums over a drum riser, to isolate the impact from the floor.

Yep!

Yeah!! I got something right!!

For drums, make it as high as you can, within reason. Drums love airy spacious rooms, and if you want to track your drums, then you need a lot of space above the overhead mics to prevent artifacts from ceiling reflections.

Up we go! No need to worry about room ratios then!?

For Sao Paolo? In summer? With several musicians in there? Hmmmm.... I would suggest going to a 12.000 BTU unit. Maybe even more than that, if you plan to have a lot of amps and other gear in there, and a lot of lights, and a lot of people... There are equations for figuring out how much cooling and dehumidifying capacity you need. Don't guess. But knowing how the climate is in Sao Paolo, I would suggest something bigger than 9.000 BTU.

Since the garage sits on the ground it stays pretty cool even on hot summer days, but maybe a 12.000 BTU wouldn't be a lot more money than the 9.000.

OK, so that's the cooling, but what about the rest of the HVAC system? I don't see any ventilation on your drawing: no ducts, no vents, no fans, no silencer boxes... You need to do that as well.

Hmmm... right... So, I've checked some threads here on ventilations and silencer boxes. How about this? I'd put one intake and one exhaust, one on each end of the studio.
The room will have 26 cubic meters, so that times 5 (cicles of air per hour) is 130. There is a model that has a capacity of 150m3/h.
One of those for the intake and one for the exhaust should do it I suppose.

Not really: You need a high level of isolation, and your plan is not going to do that. You need to do a proper "fully-decoupled two-leaf MSM isolation" system. That's the best way to get high isolation at low cost.

A few more drawings to illustrate.

Your plan would give you about 30 dB of isolation. A typical home studio gets 40 to 50 dB. Professional studios might get 60 to 70 dB, but that's not so common. It is hard to do,m and expensive.

Ok so, to be realistic, I'm aiming for 50dB here.

Each time you go up by ten decibels, you need to block ten times more energy, and it gets ten times harder. So going from 30 to 40 dB means you need to block 10 times more. Going from 30 to 50 means you need to block 10x10=100 times more. Going from 30 to 60 means you need to block 10 x 10 x 10 = one thousand times more. And going from 30 to 60 means you need to block ten thousand times more energy than your current plan. Decibels is a logarithmic scale, so things get very big, very fast as you move up. This is why it is very difficult and very expensive to get 70 dB. You could probably get to 60 dB, if your isolation plan is very very carefully designed, and you build it very, very carefully, and you have a good sized budget. It would be a lot easier to go for 50 dB.

How about now, do you think it should do it? Is 50dB (maybe 60) doable?

The budget I have is around USD 2.000. Not much I know, but for the basic I think it's enough...

Actually, no it isn't. That's about the cost of the HVAC system, all by itself. 2k would not even be enough to by the materials that you will need for your current plan, and certainly not enough to get 60 dB. Or 50. Or even 40.

Ok, maybe I could go up 1k or 2... But for the previous concept 2k was enough here in São Paulo. I have a good spreadsheet with all the materials needed. I got all the initial prices from Leroy Merlin online store, which is about the priciest you could get for construction materials here. I'm pretty sure I can get way better prices once I have the concept and the material list right and start quoting.

Your framing is incorrect. That would not pass inspection, and would not work for isolation walls. It is not even safe: the ceiling would probably collapse. I would suggest that you do some research on-line on how to frame a structural load-bearing wall, and also look into how ceilings are built safely, taking into account spans, dead loads, live loads, deflections, etc.

I'm an architect, but here in Brasil we don't work with wood frames at all, so I don;t have much experience with it. But I'm sure the walls and the celling will work, as far as safety goes. In any case, I'll check with some friends and see what they think.
And that kind of structure, indoors, doesn't need to go through inspection here in São Paulo, so no problem there.

But the biggest point is that you cannot get the type of isolation you want from the plan that you have. You need to move up to a proper two-leaf "room-in-a-room" build, with lots of mass on each leaf, a large air gap, and perfect seals.

Maybe I'm right this time! But then again... maybe not...

Thanks a lot Stuart!

And the neighbors can't really complain if it's it's not absurdly loud and doesn't go after 10pm.

Check with your local municipality to find out what the legal limits are for noise... you might be surprised! Your current neighbors might be fine with the noise, but you never know what might happen if they move away and you get new neighbors....

Or should I also build the frame, plasterboard? Maybe no need for mineral wool..

Your second diagram is correct (the one labeled "top with drywall-baixa"). That creates the proper two-leaf system all around, which is the only way to do it. And yes, you do need insulation in the cavity: without the insulation, you would lose about 10 dB of isolation. The insulation does not "stop sound" getting through: what it does, is to act as damping on all the resonances going on inside the wall. It is those resonances that reduce isolation, as they transfer energy very efficiently across the gap.

It'd be almost 19cm thick. Two layers of 12,5mm plasterboard, 5cm rock wool, 5 cm space, 5cm rock wool, one layer of plasterboard.

Would it need insulation on both leaves?

If I got it right, in the MSM system, the mineral wool is considered "spring", not mass, right..?

Not really: the air is the spring... the mineral wool is the damper. It works like the suspension on your car: there is a spring that makes that mechanically disconnects the wheels from the body, so that when you go over a bump, only the wheels move up and down, compressing the spring then it expands again, so the "bump" does not reach the car body. But there's also a "shock absorber" in the middle of the spring, to "damp" the oscillation. If you didn't have a shock absorber, the car would carry on bouncing up and down on the spring for a few seconds after every single bump... not pleasant! It would do that because it is a resonant MSM system, so it wants to oscillate at its resonant frequency. The damper prevents it from doing so. In acoustics, mineral wool is a good "shock absorber". Most open-cell fibrous insulation materials are, but some are better than others...

Yeah, I figured that it wouldn't make any diference indeed. So no angled walls!

If you are building certain types of control room, then angled walls would be needed at certain locations within the room, but then they would be carefully calculated and positioned.... for RFZ design, for example, you must have some parts of your walls angled.

Since the garage sits on the ground it stays pretty cool even on hot summer days, but maybe a 12.000 BTU wouldn't be a lot more money than the 9.000

Do the math! Don't guess! You need to calculate the actual heat loads in your room, both latent heat and sensible heat, then make sure that your HVAC system is sized correctly to handle that. Too big is just as bad as too small... You must size it correctly...

Hmmm... right... So, I've checked some threads here on ventilations and silencer boxes. How about this? I'd put one intake and one exhaust, one on each end of the studio.

Why do you have the flex duct inside the box??? One of the main objectives of a silencer box is to have sudden very large changes in cross sectional area, so that you get good acoustic impedance mismatches. That's one of the principles of how they work. If you keep the same diameter all the way through, then there is no impedance change. You only have changes in direction, which helps a bit, but is only a part of the function. Forget the internal duct. Leave the interior with a square section, to maximize cross-sectional area. But you do need proper duct liner on all the internal surfaces.

There is a model that has a capacity of 150m3/h.
One of those for the intake and one for the exhaust should do it I suppose.

It's not that easy! Ducts, silencer boxes, registers, and the room itself impose a "load" on the movement of air, which resists the fan. That laod is called "static pressure". You need to calculate what the static pressure will be for your system, then make sure that the fan can move the correct amount of air when faced with that static pressure. A fan only provides the maximum rated capacity in "free air", when there is no static pressure. As soon as you put some duct on it, it no longer can provide the same capacity, as there is now some static pressure. So it will not move the same amount of air. The manufacturer should have a table or graph that shows what the actual capacity is at various static pressures. You need a fan that can move at east 150 m3/h with YOUR static pressure in YOUR system.

A few more drawings to illustrate.

Your doors are coupled! Your inner-leaf door frame is directly connected to your outer-leaf door frame. That cannot happen. Each door frame is independent of the other. There can be NO connections at all between the two leaves. Not even a single nail...

Ok so, to be realistic, I'm aiming for 50dB here.

How about now, do you think it should do it? Is 50dB (maybe 60) doable?

50 is definitely doable, and 60 is possible, with lots of care in construction, lots of mass, a good size air gap, and good seals.

I have a good spreadsheet with all the materials needed.

Things people forget: nails, screws, many boxes of caulk, electrical installation, lights, HVAC installation, duct liner, backer rod, door seals, automatic door closers, doors, windows, mud-and-tape, sealant, paint, fabric, disposables (cleaning materials), flooring, and the simple fact that about 10% of your materials will be wasted! turned into sawdust and scraps that are too small to be usable...

Maybe I'm right this time! But then again... maybe not...

Getting closer!


- Stuart -

Check with your local municipality to find out what the legal limits are for noise... you might be surprised! Your current neighbors might be fine with the noise, but you never know what might happen if they move away and you get new neighbors....

That's the law here in São Paulo for loud noises. It can go on until 10pm. Nothing loud after that.

Your second diagram is correct (the one labeled "top with drywall-baixa"). That creates the proper two-leaf system all around, which is the only way to do it. And yes, you do need insulation in the cavity: without the insulation, you would lose about 10 dB of isolation. The insulation does not "stop sound" getting through: what it does, is to act as damping on all the resonances going on inside the wall. It is those resonances that reduce isolation, as they transfer energy very efficiently across the gap.

I was afraid you were going to say that... hahahaha ok! Got it!

Not really: the air is the spring... the mineral wool is the damper. It works like the suspension on your car: there is a spring that makes that mechanically disconnects the wheels from the body, so that when you go over a bump, only the wheels move up and down, compressing the spring then it expands again, so the "bump" does not reach the car body. But there's also a "shock absorber" in the middle of the spring, to "damp" the oscillation. If you didn't have a shock absorber, the car would carry on bouncing up and down on the spring for a few seconds after every single bump... not pleasant! It would do that because it is a resonant MSM system, so it wants to oscillate at its resonant frequency. The damper prevents it from doing so. In acoustics, mineral wool is a good "shock absorber". Most open-cell fibrous insulation materials are, but some are better than others...

Got it! Otherwise it'd act as a soundbox in a guitar.

Why do you have the flex duct inside the box??? One of the main objectives of a silencer box is to have sudden very large changes in cross sectional area, so that you get good acoustic impedance mismatches. That's one of the principles of how they work. If you keep the same diameter all the way through, then there is no impedance change. You only have changes in direction, which helps a bit, but is only a part of the function. Forget the internal duct. Leave the interior with a square section, to maximize cross-sectional area. But you do need proper duct liner on all the internal surfaces.

OK! I thought the duct wouldn't make any diference in sound transmission. It was to prevent dust getting stuck in mineral wool and then dispersed into the room. No duct then!

Your doors are coupled! Your inner-leaf door frame is directly connected to your outer-leaf door frame. That cannot happen. Each door frame is independent of the other. There can be NO connections at all between the two leaves. Not even a single nail...

Yeap! I had already changed that. One door for each leaf!

50 is definitely doable, and 60 is possible, with lots of care in construction, lots of mass, a good size air gap, and good seals.

Going for 60!

Things people forget: nails, screws, many boxes of caulk, electrical installation, lights, HVAC installation, duct liner, backer rod, door seals, automatic door closers, doors, windows, mud-and-tape, sealant, paint, fabric, disposables (cleaning materials), flooring, and the simple fact that about 10% of your materials will be wasted! turned into sawdust and scraps that are too small to be usable...

Got most of those itens. Not all... I forgot some of those stuff... And being an architect, having worked in construction, got the 10% waste considered!

Getting closer!

Thanks a lot Stuart!!

It was to prevent dust getting stuck in mineral wool

... that's why you don't use mineral wool to line the ducts and silencers! You use proper "duct liner". It has a special surface designed for that purpose...

Thanks a lot Stuart!!

- Stuart -

Hello again guys!
So now I have to figure out how to build the doors.
As Scott pointed out, I'd have one door for each leaf, totally independent, with no points of contact.
In order to make them lighter, simpler and possibly less expensive, I thought I'd avoid building those big thick insulated boxes closed with MDF. Instead here's what i'm thinking:
- Inner door: One layer of 15mm MDF, green glue, one layer of 20mm MDF, green glue, one last layer of 15mm MDF.
- Outside door: One layer of 15mm MDF, GG, one layer of 15mm MDF.
Would that work well to isolate the sound as well as a traditional studio door?
To reinforce the wall and door frame, I'll have a 15x6 cm stud around the whole frame, forming an "L".
Here are some pictures to illustrate better. Hope to hear from you guys soon!
Thanks a lot!
Henrique

As Scott pointed out,

"Scott" ???

I'd have one door for each leaf, totally independent, with no points of contact.

In order to make them lighter, simpler and possibly less expensive, I thought I'd avoid building those big thick insulated boxes closed with MDF.

That's not a good way to build a studio door anyway! Studio doors should be solid, not hollow.

- Inner door: One layer of 15mm MDF, green glue, one layer of 20mm MDF, green glue, one last layer of 15mm MDF.
- Outside door: One layer of 15mm MDF, GG, one layer of 15mm MDF.

Better, but you need to start with a thicker base. You have to attach the hinges to the first piece, and it has to support the weight and stresses of the entire door, so make it thicker. Much thicker. I normally use wood that is at least 40mm thick for the first layer. If you can't find anything that thick, the glue and screw together two layers of 20mm plywood, and use that for the base layer. Then you can put your extra layers of 15mm MDF over that. Cut each of those layers a bit smaller than the layer it sits on, so you have space to install the seals.

Like this:

To reinforce the wall and door frame, I'll have a 15x6 cm stud around the whole frame, forming an "L".

I normally do it like this: Three full studs on each side, plus extra bracing across the bay between the studs on each side. Your 15x6 would work, but I'd put something extra in there too.

- Stuart -

Quote:
As Scott pointed out,
"Scott" ???

Scott?????? I know the feeling, people call me Rodrigo all the time... hahahaha Sorry Stuart!!

Better, but you need to start with a thicker base. You have to attach the hinges to the first piece, and it has to support the weight and stresses of the entire door, so make it thicker. Much thicker. I normally use wood that is at least 40mm thick for the first layer. If you can't find anything that thick, the glue and screw together two layers of 20mm plywood, and use that for the base layer. Then you can put your extra layers of 15mm MDF over that. Cut each of those layers a bit smaller than the layer it sits on, so you have space to install the seals.

So, I was right on the principle, but need to go a lot heavier. Do you think I could use MDF as a base? Would it support the whole weight of the door? Or should I use good quality plywood?

Three full studs on each side, plus extra bracing across the bay between the studs on each side. Your 15x6 would work, but I'd put something extra in there too.

Ok... better to do it stronger than it needs, than right on it, or less!
The pictures sure help a lot too!! I guess I'm on the right track!!

One problem I have here in Brasil is that I can't find any specific acoustic sealant to fill in the gaps. There are a lot of options in silicone sealants, painter's calk, acrylic sealant, etc... But nothing specific. I'm not really sure what to look for... What characteristics should I look for in those materials? I'm not sure you can read any portuguese (pretty similar to spanish) but here is what I'm leaning towards...
http://www.cascola.com.br/pt/produtos/s ... incas.html
Once again, thank you STUART!!

people call me Rodrigo all the time... hahahaha Sorry Stuart!!

No problem, Thiago!

Do you think I could use MDF as a base?

MDF is not strong on the edges where you would have to mount the hinges. There's no grain and fiber in MDF, like there is in real wood. It's fine for adding mass, but I would not use it for the base layer. I prefer to use solid wood. Take a look around your local hardware stores and building supply stores (Do you have Sodimac in SP?) and see what they have in solid-core doors.

One problem I have here in Brasil is that I can't find any specific acoustic sealant to fill in the gaps. There are a lot of options in silicone sealants, painter's calk, acrylic sealant, etc... But nothing specific. I'm not really sure what to look for... What characteristics should I look for in those materials? I'm not sure you can read any portuguese (pretty similar to spanish)

. I can follow it reasonably ... my spoken Portuñol is a bit rusty, but I'm a lot better at reading it. The problem is that you guys have such strange accents...

Anyway, you need a good quality bathroom or kitchen caulk that does not ever harden. Even when fully cured, it remains soft and rubbery. You need one that does not shrink or crack while it is curing, and sticks like crazy to pretty much any surface. Don't get the transparent type: they aren't heavy enough. Get only the colored type. It doesn't matter which color: grey, white, black, silver,anything. As long as it is not "clear".

What I use mostly here in Chile is Sikaflex F11. You can probably get it in Brazil as well:

http://www.sodimac.cl/sodimac-cl/produc ... -ml/436984


- Stuart -

No problem, Thiago!

No hard feelings!

MDF is not strong on the edges where you would have to mount the hinges. There's no grain and fiber in MDF, like there is in real wood. It's fine for adding mass, but I would not use it for the base layer. I prefer to use solid wood. Take a look around your local hardware stores and building supply stores (Do you have Sodimac in SP?) and see what they have in solid-core doors.

Yeap, that's exactly what I was thinking! Great! It's pretty easy and inexpensive to get solid wood doors over here.

I can follow it reasonably ... my spoken Portuñol is a bit rusty, but I'm a lot better at reading it. The problem is that you guys have such strange accents...

So, let me get it right, you are chilean or an expat from somewhere else?
Portuñol saves lives (saved mine more than once)! Just do it like we do here, speak portuguese with some kind of weird spanish (or chilean, argentinian, bolivian) accent, and act confident even when people give you that "what the hell are you saying!??" look! Just the other way around!

Anyway, you need a good quality bathroom or kitchen caulk that does not ever harden. Even when fully cured, it remains soft and rubbery. You need one that does not shrink or crack while it is curing, and sticks like crazy to pretty much any surface. Don't get the transparent type: they aren't heavy enough. Get only the colored type. It doesn't matter which color: grey, white, black, silver,anything. As long as it is not "clear".
What I use mostly here in Chile is Sikaflex F11. You can probably get it in Brazil as well:

I had a quick look online but couldn't find Sikaflex f11 here in Brasil. But I'm pretty sure I can find something similar here. Now I know what to look for!

Gracias una vez mas!

So, let me get it right, you are chilean or an expat from somewhere else?

Born in Australia, and lived in various other places, including the UK, and South Africa. Sort of a "citizen of the world", I guess. But I've been living here in Chile for 30-some years now, and I can almost speak Chilean now! I speak Spanish fine, but "Chilean" is a sort of different language... So when I'm in Argentina, they think it's the funniest thing to hear a gringo speaking Spanish fluently with a perfect Chilean accent!

Portuñol saves lives (saved mine more than once)! Just do it like we do here, speak portuguese with some kind of weird spanish (or chilean, argentinian, bolivian) accent, and act confident even when people give you that "what the hell are you saying!??" look! Just the other way around!

That actually works well when I'm speaking English in places like Texas or Wales! I just put on my best Australian accent, and confuse the hell out of everyone...

I haven't been to SP in a while... I should invent an excuse to go there again, to eat some of your fantastic picanha and drink a nice cool caipirinha. I have to say that there's no better cut of meat on this planet than a good chunk of picanha, in a great rodizio .... Sigh! There's a lot of counties that claim to have the world's best meat, but I guess they've never actually tried real picanha...

Yup, I really do have to get back there. I just have to come up with a good excuse to do it...

- Stuart -

Born in Australia, and lived in various other places, including the UK, and South Africa. Sort of a "citizen of the world", I guess. But I've been living here in Chile for 30-some years now, and I can almost speak Chilean now! I speak Spanish fine, but "Chilean" is a sort of different language... So when I'm in Argentina, they think it's the funniest thing to hear a gringo speaking Spanish fluently with a perfect Chilean accent!

hahahaha I know what you mean. It's funny how different the same language can be. I guess it's the same with that weird kind of english you aussies speak. hahahaha Or the way we speak "brazilian" and people insist on this crazy theory that we still speak portuguese...

That actually works well when I'm speaking English in places like Texas or Wales! I just put on my best Australian accent, and confuse the hell out of everyone...

I have a lot of aussie friends from my Bali days and I'm convinced it's not english you guys speak...

I haven't been to SP in a while... I should invent an excuse to go there again, to eat some of your fantastic picanha and drink a nice cool caipirinha. I have to say that there's no better cut of meat on this planet than a good chunk of picanha, in a great rodizio .... Sigh! There's a lot of counties that claim to have the world's best meat, but I guess they've never actually tried real picanha...

Yup, I really do have to get back there. I just have to come up with a good excuse to do it...

- Honestly, picanha is not even the best cut we have here im my opinion... There are others that are tastier and more tender. When you come over next time I'll have you over for a bbq with picanha and some other cuts. And caipirinha, of course! It'd be a pleasure! If you really need an excuse, I have a home studio to build and could use someone who actually knows what he is doing and an extra pair of hands! hahahahah
Cheers mate!

Hey Stuart, how's it going mate!?
One quick question about my ceiling, please!
I've planned only one joist line supported by the inner walls structure. They stop just before they touch the outer leaf structure. Got it?
The top drywall panels will also be supported by these joists, that in theory are the inner leaf structure.
So my question is, how much sound isolation will I loose by doing that...? Would it completely ruim the isolation? What if I put an acoustic band between the joists and the drywall panels to decouple them (such as this http://www.artesana.com.br/produto/band ... tros-65587)? Would it solve the problem, or at least minimize it?
Thanks a lot again!
Ps: How many caipirinhas do I own you by now!??