Is there a magic size?

[Waka]

Duly noted sir Thanks!

Maybe a silly question, but can I use regular screws, nails for construction? Just like on a normal building job.
I realise the screws or nails can’t go through and make contact with the other leaf, just curious and want to do it right.

Thanks

When building structural timber framing never use screws, only nails. The reason being, screws snap when they exceed their load, whereas nails bend. This is added protection in emergencies and if there are errors in construction.
Ring shanked nails should be used for the framing, as these have a greater pull out resistance, 100mm where possible, or 75mm if the nail will go all the way through in certain places.

To nail the OSB3 (if you use it) to the frame you need to use galvanised nails (they don't need to be ring shanked) and should be about 70mm long for 18mm OSB3.

**EDIT** I was talking about the external OSB sheathing here, you don't need galvanised inside, but if you just buy a 25kg box you'll have loads spare.
*********

Staple the membranes to the sheathing with stainless steel/aluminium staples so they don't rust.

Bolt the frames to the floor (set J-bolts into the concrete, or drill and use resin and bolts once its set). Alternatively, hire a gun powder fired nail gun (Hilti gun) and shot fire through the soleplates into the concrete (get the max power cartridges)

Dan

[Soundman2020]

Maybe a silly question, but can I use regular screws, nails for construction? Just like on a normal building job.

Yup! For the drywall (plasterboard) they do make special nails/screws for this: in the USA and many other places, they are called "drywall screws" or "drywall nails". Might have a different name in the UK.

One important thing: you need longer screws or nails for the second layer! You can use normal length screws/nails for the first layer of drywall (plasterboard), but for the second layer, then have to be long enough to go through BOTH layers, and deep into the studs.

I realise the screws or nails can’t go through and make contact with the other leaf,

You'd have to have insanely long screws/nails to do that! They would have to be long enough to go through both layers of drywall, and the full depth of the stud, and also the depth of the gap between your stud frames...

- Stuart -

[elastic]

EDIT -

Ah ok now i see! You mean internal walls as in if i was building a control room, live room and vocal booth, those partition internal walls?

Super advice as always guys, reading and re-reading to take it all in!! Thanks!

Now to tackle the MAM calculator

[elastic]

Guys this MSM calculator is SO COOL!!!

What a great tool, thanks so much Gregwor and Audiomutt! Sure helpful!

I have attached mine that i did for you guys to check out and just see if i've done it right.

I couldn't see 'Cement Board' in the list? And couldn't see what type of insulation in the stud wall to choose?

I decided on 30mm air gap - no idea what this should be?

According to my calculations, if i did what i put in, i would get a total isolation of 68db - i think?

Thoughts and feedback welcome

My MSM TL Calculator Version 2.03 - TL Calculator.pdf

[Waka]

Guys this MSM calculator is SO COOL!!!

What a great tool, thanks so much Gregwor and Audiomutt! Sure helpful!

I have attached mine that i did for you guys to check out and just see if i've done it right.

I couldn't see 'Cement Board' in the list? And couldn't see what type of insulation in the stud wall to choose?

I decided on 30mm air gap - no idea what this should be?

According to my calculations, if i did what i put in, i would get a total isolation of 68db - i think?

Thoughts and feedback welcome

My MSM TL Calculator Version 2.03 - TL Calculator.pdf

You're on the right track, but you've not quite entered the correct values. When using "custom kg/m2" for thickness, you're telling the spreadsheet to ignore thickness and instead take the density you provide in kg/m2. So for 18mm thickness OSB3, I looked at the weight of a sheet online, which was listed at 35kg for a 1.2m x 2.4m sheet. This sheet is 2.88m2 in area, so 35 / 2.88 gives a density of 12.1kg/m2. So that goes in your box under OSB3.
I did the same for 15mm standard plasterboard.
The gap between the support structures is whatever space you will leave between your timber frames, I put 25 in there (for just 25mm between the inner and outer leaf frames) and selected mm in the custom units box at the top right of the spreadsheet.

For cement board, just choose custom on a standard Gypsum board and work out the density online.

I've attached the completed calculations for you:

MSM TL Calculator Version 2.03.pdf

Dan

[Soundman2020]

Ah ok now i see! You mean internal walls as in if i was building a control room, live room and vocal booth, those partition internal walls?

I'm not sure I understand your comment: All walls are built the same way...

How many rooms are you going to have?

- Stuart -

[Waka]

Ah ok now i see! You mean internal walls as in if i was building a control room, live room and vocal booth, those partition internal walls?

I'm not sure I understand your comment: All walls are built the same way...

How many rooms are you going to have?

- Stuart -

He was referring to the comment I made about the picture from Rod's book showing plasterboard on both sides of an isolated wall. I said that could only be on an internal wall because plasterboard is not weather resistant and therefore couldn't be used as an external wall outer leaf top layer.

He's only doing a single room.

Dan

[elastic]

Ah thanks Dan, really really appreciate that. So with those new calculations you put in, I’d be getting about 67db of isolation correct? (Not expecting things to be bang on just there or thereabouts)

Is it possible to use this MSM calculator for doing a wall with RISC/resilient channels? I figured it’s still MSM even though it’s semi decoupled and not a true room within a room.

I reckon I could save money and get adequate results doing RISC clips/resilient channel.

My goal was 50db isolation, but the more I think about it, I think I may have been a touch over zealous there. Maybe more like 40-45db would be more realistic.

Walls for that would be 2 layers of OSB outside, Stud wall, RISC clips, 2 layers of Plasterboard inside

The only thing that freaks me out with doing the 2 leaf method is having to buy 2 sets of doors, 2 sets of windows - essentially doubling up on price.

Yes Stuart we was just on about the walls in between, I was getting confused, again

[Waka]

Ah thanks Dan, really really appreciate that. So with those new calculations you put in, I’d be getting about 67db of isolation correct? (Not expecting things to be bang on just there or thereabouts)

Is it possible to use this MSM calculator for doing a wall with RISC/resilient channels? I figured it’s still MSM even though it’s semi decoupled and not a true room within a room.

I reckon I could save money and get adequate results doing RISC clips/resilient channel.

My goal was 50db isolation, but the more I think about it, I think I may have been a touch over zealous there. Maybe more like 40-45db would be more realistic.

Walls for that would be 2 layers of OSB outside, Stud wall, RISC clips, 2 layers of Plasterboard inside

The only thing that freaks me out with doing the 2 leaf method is having to buy 2 sets of doors, 2 sets of windows - essentially doubling up on price.

Yes Stuart we was just on about the walls in between, I was getting confused, again

Not 67dB really. You can't just add the figures for each leaf. You look at the graph underneath which gives you estimated isolation for frequencies.

At 40Hz (around Bass guitar Low E string) it estimates about 55dB of isolation and raises to around 73dB for frequencies over 315 Hz.

So it depends how bass heavy your music is.

You can't use the MSM calc for resilient clips as it doesn't account for the flanking, so anything above 40-45 dB isolation will be passed through pretty much.

It's true you need two sets of doors for a double frame wall, but that's the price for good isolation.

You wont save much money by going for a single door though. To get 40dB of isolation in a single door is a huge task. You will need it to be massively heavy. 75kg/m2 or for a standard door around 175kg! (385lb in old money!) you would need it to be lead lined for that and have probably 6 extra heavy duty hinges and massive framing and support all around the door and it's stops. Aswell as multiple seals and an industrial door closer, just to stop it slamming and taking a finger off.

Look at Rod's "super door" design for ideas. That will get you maybe 40dB isolation.

Your windows definitely need to be double glazed, but not standard double glazing, you need thicker glass, so should be bought as individual panes and made up on site.

You will almost certainly save money using resilient channels/clips but you will struggle to get anything more than 45dB isolation overall.

And your door will probably cost the same as two doors built as MSM. The windows will be the same either way, but if they're both in the same wall it will maybe cap at 40dB isolation due to flanking.

So overall you will save money on the walls, but not other things really and lose probably 10dB of isolation maybe more at low frequencies.

Dan

[elastic]

Right ok, that’s super info Dan, cheers mate! Answers a lot, I shall stick with the 2 leaf system.

I’ve put in bob golds Calc and the amroc calculator my internal dimensions :

5.5m x 3.5m x 2.5m

It passed all 3 BBC tests and was just in the bolt area too. Those dimensions give me 48m3 and 19m2 -

I think that’s pretty good from what I’ve learned so far?

Stuart I remember you said 40 cubic and 20 floor space was a minimum for a decent room so I’m quite happy there.

Funnily enough when I increase the room length to 6m it puts me on the border of the bolt area, what looks like a worse position on the bolt map than before. I would’ve thought increasing the size would be better. I’m probably misreading something?

I’m still weighing up pushing to 6m x 3.5m x 2.5m - it just depends how thick the walls will be.
At the moment I’ve calculated my walls to be about 30cm thick overall (that’s 2 layers of OSB, stud, 2.5cm air gap, stud and 2 layers of plasterboard)

Quick question too, should I be too concerned about these tree roots and my base? The trees will be about 1m / 1.2m from the base.

75D46A4B-90F7-429B-B3D4-595F4E65A9DA.jpeg

[elastic]

Also, quick question - if I have a 2.5m ceiling inside, should I be ok with the exterior being 3m high at the front sloping slightly to the back?
I’ll be 1m from the fence so will go through the planning route.

The lower the better externally for financial reasons and to keep the neighbours ok.

Thanks

[Waka]

Funnily enough when I increase the room length to 6m it puts me on the border of the bolt area, what looks like a worse position on the bolt map than before. I would’ve thought increasing the size would be better. I’m probably misreading something?

I’m still weighing up pushing to 6m x 3.5m x 2.5m - it just depends how thick the walls will be.
At the moment I’ve calculated my walls to be about 30cm thick overall (that’s 2 layers of OSB, stud, 2.5cm air gap, stud and 2 layers of plasterboard)

Again, in the case of rooms this size, any gain in volume is almost always preferred, unless it throws you wildly out of wack with the ratio, or makes the room asymmetrical. As long as the 6m x 3.5m x 2.5m passes all three BBC tests you should be fine. If you can afford it and fit it in, then go for 6m in length.

Quick question too, should I be too concerned about these tree roots and my base? The trees will be about 1m / 1.2m from the base.

Ideally you want trees at least the same distance away from your foundations as they are tall. So a tree that is 2m tall should be at least 2m away from your foundation. If not then you may need some additional professional advice for your foundations.

Also, quick question - if I have a 2.5m ceiling inside, should I be ok with the exterior being 3m high at the front sloping slightly to the back?
I’ll be 1m from the fence so will go through the planning route.

The lower the better externally for financial reasons and to keep the neighbours ok.

You really need to design your studio (on SketchUp) before you can make these kind of decisions. For example, it might be a good idea to fit your ventilation silencer boxes into the ceiling/roof of your studio and you would need to have enough space for them. You need to consider what kind of roof design you are doing too. A cold roof requires ventilation (meaning you'll need to go three leaf), whereas a warm roof requires different materials for construction. You might be able to get away with a little less than 3m height at the low end, but you'll have to work out the complete roof design before you'll know for sure.

Of course you could put on the planning application you want a 3.2m height and then you're safe either way, if it's approved, if they say to lower it, then you can lower it a bit.

Dan

[elastic]

[quote=“Waka”]
No problem . For decoupled room within a room you build two free standing rooms. The outer frame has 4 walls and roof trusses/joists sitting on it. The inner frame has 4 walls and ceiling joists sitting on it, and doesn't touch the outer framing at all, at any point.
[/quote]

Thanks Dan, I’ve been reading your last post about hot roof/cold roof and doing some research. I’m struggling to picture how the roof attaches to the walls. Forgive my lack of knowledge.
I kept re reading your quote above, but can’t quite picture it.
I’m hoping to chat with my Uncle today who’s a carpenter who will hopefully help with the build and has done loads of roofs, so he might be good to explain it too.

Main things re roof would be to save space. Any suggestions and ideas on what you think I’d be best doing would be appreciated

Thanks

[Waka]

Thanks Dan, I’ve been reading your last post about hot roof/cold roof and doing some research. I’m struggling to picture how the roof attaches to the walls. Forgive my lack of knowledge.
I kept re reading your quote above, but can’t quite picture it.
I’m hoping to chat with my Uncle today who’s a carpenter who will hopefully help with the build and has done loads of roofs, so he might be good to explain it too.

Main things re roof would be to save space. Any suggestions and ideas on what you think I’d be best doing would be appreciated

Thanks

If you have a look at my build thread to see how I built my roof. I went with a ventilated cold roof and three leaf design for ease of construction.

The outer roof joists just sit on the outer walls. And are nailed to the top plate (you can get timber frame joist clips too)

Then inside the room you build your inner walls a bit shorter and sit another set of joists on these walls for your ceiling.

My roof design is like this (remember it's three-leaf)
Outer walls 3m height, joists sitting on top of these with a 100mm rise over the 4m run.
OSB3 T&G roof deck > Epdm rubber sheet glued to the deck > raised trims on three edges and a gutter trim on the lowest edge. In between the joists I have loft insulation and about 100mm of air gap above it for air flow. This is my ventilation, it is not sealed.

The underside of the roof joists is my sealed "outer leaf" and consists of OSB3 > plasterboard > plasterboard, with each layer caulked.

Now on to the inner leaf:

The internal walls are built about 2.35m tall, and a new set of joists are sat on top of these. Insulation sits ontop off these joists filling up to the outer leaf. I wanted an inside out ceiling, so I built ceiling modules and fitted them between these joists. The modules were just two layers of 15mm plasterboard on frames and screwed into the sides of the joists.

There is a 200 - 300mm cavity between my inner ceiling and outer leaf to allow me to fit my silencer boxes in and also maintain isolation even though I'm using three leaf design and an inside out ceiling.

You can look at my build thread for details (it's still ongoing) :
http://www.johnlsayers.com/phpBB2/viewt ... 10&t=21269

Dan

[elastic]

Super Dan, thanks for such a detailed reply. It always helps And your thread looks ace. It’s a lot easier to understand with pictures and when someon explains it.

Been a week off from the project so just getting back into it now.

Does the HVAC unit have to be in above the ceiling?

Also, forgive my lack of knowledge, but what is an inside out ceiling?

Thanks