Drumroom for son

Hi, Im currently in the planning stage of trying to build a space so my son will be able to play his drums, we recently bought a new house so we don’t want to annoy the new neighbours, but as he has exams for his drums and is hoping to get into university soon, I need to sort something out for him. I’ve done quite a lot of research - in fact thats all I seem to be doing - and I think I’ve got a good idea of what I’m wanting to achieve although I would feel a lot better running it past the experts. We have a detached garage that I’m wanting to split in half so he can have his space and I can have mine, the drum space will be 3.2m x 3m x 2.1m i know its not very large but as long as he has somewhere to play his drums he will be happy The drum room will be from the red line to the back of the garage on the left, as you can see quite a lot of it is built into the garden so kind of under ground ,the window will be took out and blocked up with concrete blocks and rendered. The garage is built with 140mm solid concrete blocks and rendered on the outside, the floor is concrete slab and the roof is felted with roof tiles. We managed to borrow a sound meter from my sons teacher and when on his drums it reads about 125db the average reading of our environment was between 50db and 75db as we live next to quite a busy road in the daytime, our nearest neighbours house is about 8m away from the garage this is whom I’m trying not to annoy. My budget started off at £1500 but after some research I’m thinking more about £2000 i don’t really want to go much more but willing to if i knew it was going to be worth it in the end. He would only use the room through the day or early evenings but it would be nice for him not to be on a time limit if i can make it that good. So my plan was to build a room within a room with 2x4 studs 2 sheets of 15mm plasterboard with green glue in-between , as he is only having the back of garage i was going to partition it using a double stud or maybe a staggered stud wall this is what will have the doorway in, I’ve got my eye on 2 fire doors on ebay as we speak so hopefully i will be getting these. The ceiling, as it is only 2.1m high i was going to put the new joists in-between as to retain a bit of hight but still decoupling from existing structure. As for insulation i was going to get acoustic rockwool rwa45 slabs 100mm or 75mm not sure yet. Does it matter what sort of insulation you use ? Does it aid in soundproofing or is it purely for insulating the room ? I think my biggest problem is going to be the ceiling, i was thinking of plaster boarding the existing joists first and then build rwr but as i am going to put the new joists in-between to keep some hight I’m unsure what to do ? So thats as far as I’ve got, I’ve tried to put as much info as i can think of Any advice would be a great help Thanks for reading, Barry

Hi Barry, and welcome to the forum! :)

the drum space will be 3.2m x 3m x 2.1m i know its not very large but as long as he has somewhere to play his drums he will be happy

That's fine. This is not intended to be a recording studio, just an isolation room for drums, so the low ceiling won't be too much of an issue. And as folks sometimes say around here: a room that isn't ideal is still a hell of a lot better than no room at all! On the building and your plan: OK, you have some good things going for you, and some not so good things:

The garage is built with 140mm solid concrete blocks and rendered on the outside, the floor is concrete slab

That's the "good part"! Lots of mass there, in both the floor and walls, and the floor is "slab on grade", so that's excellent.

and the roof is felted with roof tiles.

That's the not so good part. More on that later, but this is the weak link, and will be the source of your nightmares in coming weeks.... :) But there are ways of dealing with it...

We managed to borrow a sound meter from my sons teacher and when on his drums it reads about 125db

:shock: That's rather on the high side! Not impossible, but he must have been bashing the hell out of those drums to produce 125 dB. You did measure with "C" rating and "slow" response, right? Also, at those levels, I hope you were all wearing good hearing protection. At 125 dB, you suffer irreversible hearing loss after about 3 1/2" minutes of exposure. 125 dB is also beyond the threshold of pain: that must have been hurting your ears physically. The other possibility is that meter you used is not calibrated or not good quality: There's a lot of cheap and useless Chinese junk on the market right now: those are the meters you can pick up for around US$ 50 or less on e-bay and Amazon, new. A good meter will cost around US$ 100 or so, new. Brands like Extech, Galaxy and suchlike. One other possibility is that you were not using the meter correctly: Measurements should be taken roughly at chest height, and about three feet (one meter) away from source, with the meter held out away from your body, and the mic angled upwards at about 45° or so. I'm not saying that your son didn't really produce 125 dB: just that such a level is about 10 times higher than you'd normally expect for drums played in typical manner. 125 dB is about the same level as putting your head about a foot away from a pneumatic hammer going flat out....

the average reading of our environment was between 50db and 75db as we live next to quite a busy road in the daytime,

Where did you take that reading? Inside the room, our outside? It would be helpful to have a reading of the drums measured at the location of your neighbours house.

So my plan was to build a room within a room with 2x4 studs 2 sheets of 15mm plasterboard with green glue in-between

That's a good plan for the walls, but the ceiling is a different issue...

as he is only having the back of garage i was going to partition it using a double stud or maybe a staggered stud wall this is what will have the doorway in

Isolation is an "all or nothing" system. It is only as good as the weakest path out of the room. If you do your floor and three walls to the level where they give you 50 dB of isolation, but the other wall only gives you 40 and the ceiling only gives you 30, then your sum total isolation is 30. Implying that you wasted a lot of time and money getting your good walls up to 50 ... Think of it like a fish tank: If you put glass on only three sides, but they decide to use thin plywood on the back, and cardboard on the bottom, how well will that hold water? :) Even though the glass will work fine, the other materials wont: water will leak out through those, splashing all over the place. Same thing applies with your room: If you want to stop sound at a certain level of isolation, then ALL the walls AND the ceiling, AND the door(s) AND the window(s) AND the HVAC system AND the electrical system must ALL be done to the same level. In other words, you'll probably have to beef up that forth wall a bit more to get the high levels of isolation you need, and you will DEFINITELY need to do something about the ceiling/roof.

The ceiling, as it is only 2.1m high i was going to put the new joists in-between as to retain a bit of hight but still decoupling from existing structure.

Great, but what are you going to do about the ROOF? With your current plan, the roof is your outer leaf, yet it has low mass, and is not sealed: that's not a very god outer leaf. You won't get good isolation out of that. To fix that, you have two options: 1) Beef up the mass of the roof, and seal the entire thing air tight. That's probably not an attractive offer, and possibly not even a legal alternative. Roof decks usually are required to be ventilated underneath, to prevent overheating, the formation of condensation, and other nasties. Sealing up the roof space defeats that, which is bad in may ways. So you might not want to go this way. 2) Don't touch the roof: leave it like it is, and instead go for the dreaded "three-leaf" system. In other words, slap a couple of layers of drywall on the existing joists, carefully sealed and with GG, to act as your "middle-leaf", then build your complete "room-in-a-room" below that. I would go for option #2. However, that does mean that you lose quite a bit of ceiling height.

As for insulation i was going to get acoustic rockwool rwa45 slabs 100mm or 75mm not sure yet.

The more, the merrier! :)

Does it matter what sort of insulation you use ?

As long as it is open-cell, and its density is roughly in the "good" range for that type of insulation, then you are good. If you choose fiberglass insulation, then the density needs to be around 30 kg/m3, and if you use mineral wool the it needs to be around 50 kg/m3.

Does it aid in soundproofing or is it purely for insulating the room ?

Ohhh yes! It does aid, and big time! Basically your "room-in-a-room" plan creates something called a fully-decoupled two-leaf MSM system. That's a resonant system, where MSM stands for "Mass - Spring - Mass". The layers on each side of the wall are the Mass (in your case, your outer-leaf mass is the concrete walls, and the inner-leaf mass is the drywall). The spring in the middle is the air. You don't normally think of air as being "springy", but as far as sound waves see it, it sure is very springy. So you have a resonant system, which works exactly the same as a weight bobbing up and down on a spring: it oscillates at its natural frequency. You "tune" your wall to the lowest frequency you can get by using the correct mass on each leaf, and the correct size of the air gap. However, the air in that gap can also resonate in many other ways, and you do not want that to happen, since resonance is a very efficient method for transferring energy. To stop the air from doing all its resonant things, you "damp" it by putting the insulation in there. That's sort of like taking your weight that is freely bouncing up and down on its spring, and instead of letting it do that in air, let it do that in a tub of molasses... The molasses heavily damps the oscillation, to the point where it just doesn't happen. Insulation is to sound waves as molasses is to a bouncing weight. So yes, you totally, absolutely and definitely need to fill the air cavity with insulation. Oh yes, and it also has good thermal properties... :)

I think my biggest problem is going to be the ceiling, i was thinking of plaster boarding the existing joists first and then build rwr but as i am going to put the new joists in-between to keep some hight I’m unsure what to do ?

Your thinking is spot on. You have the right idea. Yes, it will be a 3-leaf system to a certain extent, but it is still your best option. Unfortunately, it does mean losing head room. However, if you build the ceiling "inside out", then you won't loose any additional head room to the acoustic treatment that your room will need, so from that point of view you gain space up there. Yes, the final outcome will be a low finished surface, but you don't have many other options, realistically, and as you say, this is just a practice room for drums, not Abbey Road! :) - Stuart -

Hi Stuart and thanks for the quick reply really appreciate it,

That's rather on the high side! Not impossible, but he must have been bashing the hell out of those drums to produce 125 dB. You did measure with "C" rating and "slow" response, right?

Ive never used a sound meter before so you may be right and i might not of used it correctly but my son does wear ear defenders and likes his thrash metal :twisted:

I would go for option #2. However, that does mean that you lose quite a bit of ceiling height.

Am i right in thinking you mean something like this ? ( sorry about the drawing i can't seem to workout sketch up ) If my budget was higher would i have any other options as to how to solve my ceiling problem because Iike you say the whole room is only going to be as good as the weakest path. Thanks again Barry

Hi Could anyone please confirm this is the best and maybe only option for my ceiling ? its just i can make a start once I've decided on ceiling construction. Thanks in advance Barry

Am i right in thinking you mean something like this ?

That's the general idea, yes, except that the final inner-leaf "new joists" do not touch the existing building anywhere: they rest ONLY on the new inner-leaf walls which you will be building. So those joists will be shorter than the existing ones.

( sorry about the drawing i can't seem to workout sketch up )

Check out YouTube: There are numerous tutorials on how to use SketchUp. It's not as hard as it looks at first glance! :)

its just i can make a start once I've decided on ceiling construction.

I would suggest that it is waaaaay to early to make a start! You should get your entire design fully complete before you lift a hammer or even buy a bag of nails and some 2x4's. There's a huge amount of stuff that goes into a design, even though yours is just a very simple room. For example: doors are critical for isolation, so you need to have those designed properly, including the framing, double perimeter seals, heavy-duty hinges (to handle the extra weight), and the automatic door closer. Windows are critical too (if you have any, of course!). Your electrical system is also very important: you cannot just punch holes in your new inner leaf to put in plugs, switches and light fittings! Ventilation is another biggie: the room has to be sealed in order to be soundproof, but ventilation implies making big holes in the room to get air in and out. So you need to design the silencers to go on those holes, so that sound cannot escape. Etc. If you don't have all of that lined up and fully designed BEFORE you start building, then you are in for a major disaster. Not trying to scare you! Just pointing out the way it always, invariably goes with builds that are not designed properly: check out a few threads on the forum, and you'll see that those who are not prepared either end up with lousy rooms that don't isolate and sound awful, or they end up having to tear things down and re-build them the right way. And there's also a rather large number of build threads that just sort of come to an inconclusive halt after the builder figured out that his build had gone wrong. We never hear about those guys again, but it doesn't take much imagination to figure out why their build threads are abandoned... So please take the time to learn SketchUp (it isn't that hard... really! I promise! :) ), and do the design properly, taking into account all the aspects. Post your design here as you move forward, so we can comment on it and perhaps suggest ways of improving it, or of doing things another way to make it easier / cheaper / better. - Stuart -

Hi Stuart I think your right i need to learn sketch up , its just I'm more of a get my hands dirty type of person than a keyboard basher ( still type with one finger :lol: ) so it may take a while to learn . So thanks again for the advice and hopefully il get some complete plans posted Cheers Barry

Hi I think I've finally got my head around sketch up and would be grateful for any feedback on my design, i haven't included the doors but i have 2 fire doors 45mm thick which i would be using Cheers Barry

Hope my designs not that bad, any feedback good or bad thanks Barry

It's looking pretty good, Barry. Nice work! :thu: It pays to learn SketchUp. :) Just a couple of minor issues: 1- Use double top plates on your stud framing, not just single. For many reasons. 2- Install the ceiling drywall so that it goes all the way to the top plates, with the wall drywall rising to just underneath it 3- You'll need nailing strips and cross bracing on the ceiling framing. Right now, you have no place to nail the ends of the ceiling drywall, where they meet the top plates. 4- Use triple studs on each side of the doorway rough openings, instead of just double studs. The doors will be VERY heavy, so they need the extra support. You don't want the framing sagging and bending as the doors open and close. 5- Fix your door headers: They must be supported with jack studs, and have cripple studs above (or solid header above). 6- Have you considered doing your ceiling "inside out"? It might make sense in your case. Apart from that you seem to be on the right track! :) - Stuart -

Hi Stuart and thanks once again for the reply i can see how busy you must be replying to all these forum posts.

It's looking pretty good, Barry. Nice work! :thu: It pays to learn SketchUp. :)

Thanks for that i quite enjoyed it once i got my head around it, now the wife wants me to design the kitchen with it :cry: Ive took note of them minor problems you listed and I’m going to try and edit my design in sketch up. Apart from doing some more research into door seals and extraction systems for the room my only problem now is understanding how to do the ceiling inside out? Ive had a look at other forum posts and Johns ceiling plans about inside out ceilings and still don’t get it ( i know I’m stupid ) I understand how i would construct the inner ceiling inside out but not sure what i would do with the outer one ? or would i just board this like normal underneath? Thanks again Stuart :D Barry

Hi Stuart and thanks once again for the reply i can see how busy you must be replying to all these forum posts.

Yup! It's become practically a second full time job! :shock: :!: And even then, I can't keep up with all the threads... :(

Thanks for that i quite enjoyed it once i got my head around it, now the wife wants me to design the kitchen with it

Ahhh! The domestic dangers of learning a new skill... :)

my only problem now is understanding how to do the ceiling inside out?

The basic concept is simple: Instead of nailing your drywall underneath your joists, you nail it on top of them. That's all there is to it. That leaves the gaps between the joists INSIDE the room, where you can use them for acoustic treatment, instead of outside the room, where the space is mostly lost...

but not sure what i would do with the outer one ?

The outer one is there already, right? So just leave it like it is, or maybe beef it up with more mass if needed. And seal it well, always. - Stuart -

Thanks again Stuart :) The problem I'm having is understanding how to construct the inside out ceiling with my existing joists. I would have to cut plasterboard into pieces as i couldn't get full size sheets up in-between the joists to fit on top ? also where my joists sit on the wall plate there would be a void in-between wall plate and plasterboard , Would i just fill this with a piece of stud timber ? Or am i getting this completely wrong. Thanks again for all your advice Barry

Hi Any advice is more than welcome as i really need to make a start on this as my son is constantly giving me headache :ahh: thanks in advance Barry Had a bit of a rethink see what you think. If i was to get some 18mm osb and cut it into pieces small enough so i can get it up into my roof space and screw into top of joists then underneath attach 2 x 15mm plasterboard, Then where my wall plate is attach 2 x 15mm plasterboard to blank off the void. Hope this makes sense Also would you use gg on both inner and outer leafs? Thanks Barry

Hi Well i think i will have to go with this outer leaf plan as i really can't think of any other way, so heres hoping it works. Barry

I would have to cut plasterboard into pieces as i couldn't get full size sheets up in-between the joists to fit on top ?

Careful there! You might not be able to do that! Your roof deck needs ventilation from below, for a couple of reasons (heat, condensation, etc.), and that is normally accomplished with vents under the eaves, and either a ridge vent or gable end vents. You cannot block those. If there are no eave vents but there ARE ridge vents or gable vents, then the airflow is probably intended to come from the room itself. So before you go sealing off any of that, you should first look into the the roof deck ventilation issue: Only if you are 100% certain that it is done correctly, only then should you proceed with your plan to create the leaf in the manner you are thinking of. - Stuart -

Hi Stuart and thanks again, As for ventilation I'm only using half of the garage to build a room in so the roof will have plenty of air circulation as it will still be all exposed Thanks Barry