New build small size high isolation project

[Purelythemusic]

Just measured, we have 470mm between the underside of the beams and the timber shutter for the sleeves.

We tried to place the beams so they allowed extra room for manoeuvre...

[Soundman2020]

Excellent! I also figured out a way to fit in the sleeves "sideways", so you won't need to do any planing on the shutters.

- Stuart -

[Purelythemusic]

Oooo almost got it done today, took a while coating the underside of each block! Ended up with a good system.

Looking forward to next week hopefully having the roof topping and floors done!

End of play today:

[Soundman2020]

The speed is still dazzling! Great job you are doing. And you'll be able to get a bit of a feeling for the isolation, now that the roof is in (except for the lack of doors, of course).

Tom, on the door issue: I checked the emails going back, but I don't have the specs for the doors you were talking about with Luke: I have the e-mails, but no attachments. Please could you e-mail those to me.

- Stuart -

[Purelythemusic]

Hi All,

Thankfully just remembered that if I’m getting the floor poured I need to pop in some cable and or conduit!

I’ve just bought some external cat 6 cable to run back to the house in my trunking with rope in : ) I’ll use the same grade cable to run under the new floor. I actually want this cable to come up to where the desk is...don’t I? I am not sire whether to just bury the cable under the insulation then up through the concrete so the concrete makes a seal round the cable, then how to seal the cable entering the wall from the outside of the inner room wall?
Should I use some round conduit (as would normally) which could take the same route but would have to rely on sealant?

Also, Stuart, could you give me a drawing of the best likely area that the listening position might be? I’m happy to do two sets of flat conduit one to each soffit side or just ome in the middle. I am thinking of 225x25 trunking. Don’t think any of the cables have connector diameter bigger than 23mm or so... I should check! Just be XLR’s I guess...

[Soundman2020]

Thankfully just remembered that if I’m getting the floor poured I need to pop in some cable and or conduit!

Ummm.... Yup! For sure! And more than just "some" as well.... you need lots of things going in there: Electrical power, Cat6 (several), analog snake to your stage box at the rear of the room for your instruments inputs, also headphone mixes, returns, maybe effects inserts, Internet, CCTV (if applicable), maybe KVM if you need to control your DAW from a different location in the room, perhaps lighting circuits if you want to control your lights while seated at the DAW (very cool), maybe USB, HDMI, or even (gasp!) Firewire (can't believe I said that...), Thunderbolt, etc, etc. Plus future expansion. There's LOTS of stuff you should allow for to be connected around your room. And since you don't know what half of that will be yet (especially the "future expansion" stuff....), conduit is the way to go.

So, I would run a couple of conduits runs from the mix position to the electrical distribution panel, a couple more to to the spot where your internet connection comes in (and telephone connection, and cable connection, and alarm connection, and intercom connection...), several to the front of the room (between or in the soffits), and several to the rear of the room. That's just runs from the mix position. In addition to that, you will also need conduit running from your electrical panel to the soffits (to power the speakers), and to the rear of the room (to power the gear you'll have back there while tracking, etc.), and also for outlets for "utility" electrical loads, such as extra floor-standing or table-top lights, cell phone chargers, laptops, the vacuum cleaner, coffee pots, pizza warmers, etc.

I actually want this cable to come up to where the desk is...don’t I?

Yup! Which means we need to decide on the desk design first... The esk design dictates where the desk legs will be, and that dictates where the conduit has to come up through the floor.

Should I use some round conduit (as would normally) which could take the same route but would have to rely on sealant?

Right. Do ALL of the above with conduit, not with cable. Conduit gives you flexibility, in that you can add new cables later, take out old ones that you no longer use, replace damaged cables, etc. You can't do that with wires embedded in concrete. And yes, the ends have to sealed very well, but in such a way that you can remove the seal if you need to add/remove/replace cables, then re-seal. I'll walk you through that when the time comes.

A word of warning: Use only GENTLE curves on your conduit! No tight corner. Only large radius bends. It's hard enough to pull cable through conduit as it is, without complicating your life around tight bends. And do also remember to put "fish tape" in each conduit as you are installing it, so you can pull the wiring through later! Fish tape is often just bare galvanized wire these days, or fiberglass strand, or whatever. Anything strong and flexible that you can attach a cable to at one end and use to pull it through the conduit. IT has to be STRONG: you might need to pull hard.... very hard....

Also, Stuart, could you give me a drawing of the best likely area that the listening position might be? I’m happy to do two sets of flat conduit one to each soffit side or just ome in the middle.

With a typical desk, you'll bring the cables in under the legs, not under the middle of the desk. Your own legs and feet go under the middle! So ideally you'd have two runs of conduit going to the desk: one to each desk leg location. Each of those then splits out with conduit to each of the locations mentioned above (electrical panel, soffits, room rear, etc.). If your desk is well designed and has a large built-in cable tray for running plenty of cables side-to-side, then you can probably get away with doing just one leg of the desk, and crossing over from there within the desk.

I am thinking of 225x25 trunking. Don’t think any of the cables have connector diameter bigger than 23mm or so...

If you plan on running cables that are 23mm in diameter, then you need at least 32mm conduit, and probably 50mm! The conduit and cable have to bend around the curves: it's not just a straight run. You'd never be able to get 23mm diameter cable into a 25mm diameter duct. Oversize everything, and run extra conduit, even if you are certain that you won't need it. If you don't use it now, you will later... At some point in the future, you'll buy a new-fangled "super hyper thing box" that does magic tricks, and needs wiring in.... Also, if you plan to pull an analog audio snake through conduit, it needs to be very large as you have to get all the XLR connectors through too... or cut them off, then re-solder them on after you pull the cable through.

Pulling cables through conduit is not fun. Frustratingly, maddeningly, head-bangingly, "not fun"!

Another alternative, which doesn't look very neat at all, is to build cable "tunnels" on top of the floor, after you finish the room, like this:

It is also possible to cut a "trough" or "chase" in the floor concrete after it has cured, as long as it is thick enough to do that, then cover it with a metal panel before putting in your final flooring. Like this:

The wooden box in the second-last image is the desk leg, where the cables go up.

But the neatest way is to embed plenty of conduit in the floor slab itself.


Getting back to this: "Also, Stuart, could you give me a drawing of the best likely area that the listening position might be?" Sure! It will take a few hours to do that, but I'll need a bit of input from you on some things, so I'll e-mail you on that.

One other point about embedding conduit in concrete: it wants to float! Conduit is just an air-filled plastic bubble, so it does not want to stay in the wet concrete: it wants to rise to the surface. You MUST tie it down to whatever is under the concrete, to prevent it from rising and floating, or even just moving. Anchor it down firmly.


- Stuart -

[Purelythemusic]

Hi Stuart,

Thank you and thank you for the email, great! I look forward to the challenge getting air filled plastic to sit down...it’s going on to plastic with Insulation underneath...maybe I should fill the conduit with water : )

I only used 23mm as an example, but a poor one as yes 25mm conduit is not going to allow any movement. I will see what I can find! Maybe smaller round conduit is better, may be structurally better too.

The other tricky is the concrete is only 70mm... so I can’t go too big... I can go many though... I’ll keep thinking.

[Soundman2020]

Quick thought: The concrete you are using is basically self-leveling cement, right? How about if you put in all your conduit down on the "plastic-over-insulation" base, then put in a light gauge metal mesh over that, to weigh it down, keep it all in place, and stop it from rising, then do your pour.... Normally you would use mesh chairs to keep the mesh in the middle of the middle of the concrete (so it doesn't sink to the bottom), but the conduit would do that for you (you might still need some chairs, though, in the areas where there's no conduit).

You don't actually need the mesh, of course, but it won't do any harm, and serves the purpose of weighting down the conduit so it won't float, as well as strengthening the concrete, to help reduce cracking. Ask your contractor if that would work OK with the mix he plans to pour. The trick will be to find the right size mesh, so it is heavy enough to keep the conduit down! If necessary, you could pull metal chain through the conduit as well, to add even more weight to it, then pull it out afterwards (while using it to pull in another piece of fish tape!).

Just some random thoughts on how to do this.

If you only have 70mm total thickness, I would try to only use 32mm conduit, max. That's already nearly half the total slab thickness... Hmmm... That steel mesh is sounding better and better...

- Stuart -

[Purelythemusic]

The contractor said that mesh would be a bit of a hassle (I’m yet to inform him of the conduit...todays job amongst the others) and wasn’t necessary with the mix...it’s macro mesh reinforced high flow, high polymer...this one I thing:

https://www.thermascreed.com/liquid-flo ... d-concrete

The concrete toppings bit at the bottom...

A spin off the idea might be to use heavy gauge rebar like the 16mm lengths we used in the raft. I’ll chat to the screedman later amd see what he thinks... it could be a heavier mesh like 12mm could be cut to size just over the conduit which would strengthen where it’s thin and weigh down the conduit too...

[Purelythemusic]

Spoke with the contractor, he said rebar or mesh would make their job tricky...not sure why but there you go! We were chatting through the options and thought using underfloor heating insulation clips would work but they’re only for 15mm pipe, he suggested tape would work to fit it down to the Membrane and after today using DPM tape instead of duct tape which we usually use, it bonds sooo well to the membrane, I’m confident the tape will work well!

I’ve gone for 25mm conduit everywhere I can and 20mm where I can’t. I’ve bought conduit bending spring amd we’ll have heat guns on it in the morning to do big radius bends. I remembered I had a cable pulling set but the fibreglass pullers in one coil should work fine through the runs we have...nothing too long or too bendy!

When I’ve walked into the room today imagining where everything will be, it seems to make sense to have the door swing open to the back of the room, so that’s where I’ll put the distribution board. I’ve gone for 10mm SWA cable which would take some 70amps, way more than will be drawn but the voltage drop will be very minimal.

I was hoping to move the concrete contractor a few days ahead so we can make sure the conduit is exactly where we need it but they would reschedule 2 weeks or more away which would leave us with not a lot to do so we’ve been scrambling to finish the roof blocks, slurry the block and beam, build a single course of bricks to retain the thickness of the outer leaf, then get the Damp membrane, insultion and vapour membranes onto the roof, inner room and corridor!

All that we need to do tomorrow is shuttering at the roof and the conduit runs in the floor...by 12:30... I have extra pairs of hands ; )

The pics show almost everything in except for the vapour membrane on the floor and the top membrane on the roof but you get the idea...

[Soundman2020]

I just sent you an e-mail with the conduit layout, Tom. Check your inbox (and maybe Spam folder too, if you don't see it... )

- Stuart -

[Soundman2020]

The tape idea sounds good. Just tape it down like crazy!

[Soundman2020]

Also, I would suggest having the door open the other way: towards the front of the room: I think you'll find that will be least intrusive. If it opens to the rear, it will probably get in the way of musicians, equipment, instruments, mics, cables.... Opening to the front (see the video) means that it opens into the space between the desk and the wall. Not a problem.

Stuart

[Soundman2020]

Here's the conduit layout, Tom. Just a single still image from the video. Orange is electrical conduit, blue is signals:

The pink circles are just markers: not real physical objects. They just show the location of the desk legs, where all the conduit will come up through the floor, as a bunch. The center of that bunch is at 900mm from the side walls, 1650 from the front wall. That gives us a bit of leeway with the dimensions and location of the desk.

All the other ends of the conduit should come up as close as you can get them to the walls. I'm just showing plugs and stage boxes for reference purposes only! Those are not the real plugs or connection panels that you will actually use (especially considering that those are American outlets!). They are just place markers. Well figure out the actual plugs and panels later.

Generally I prefer to take more time to work through these layouts, and nudge them around to optimum locations as the design advances, but your build is progressing so fast! NASA should hire you to direct their space program: We'd have men on Mars by last week, and on Neptune before the end of the year!

- Stuart -

[Purelythemusic]

Thanks so much Stuart!

Concrete is going in now!

Bit rough n ready!

We used all the white conduit the merchant had and went back for black...