Hello again folks, Next episode in the continuing `PVC Trunking Saga`!

following on from my recent posts about fitting horizontal PVC electrical trunking to my music room (to house cabling and electric sockets).

Following your advice Brien I told the electrician not to fix trunking to the RCs but to use the suggested toggle bolts. I had an email today from him which I find frustrating to some degree partly because I don't have the knowledge to respond decisively. his email is copied below, my primary concern is to get it done right not necessarily cheap.

Drilling countless holes through your soundproof plasterboard would be self-defeating so I think the spring toggles are a bad idea for many reasons as listed below but I do have a solution which I'll set out below that. Anyway, the reasons are as follows:

1. In order to fit toggles a hole for each between 12 and 18mm depending on type has to be drilled through both layers of soundproof plasterboard.
2. The trunking has to be fixed every 600mm top and bottom which equates to 7 along the top and 7 along the bottom of each 3-metre length of trunking. That's 72 x 12-18mm holes through the soundproof plasterboard.
3. In order to fit toggles the trunking has to be mounted on the wall temporarily with screws at each end and at least twice more across the length of the trunking so that the trunking can be held still in a level position. Then the trunking has to be taken down whilst the holes are drilled. Next, the holes having been drilled each fixing hole in the trunking has to be fitted with a toggle. Once this is done the trunking is mounted on the wall whilst the toggles are done up. See below.
4. Toggles are also very difficult to do up as the spring element that sits behind the wall often doesn't engage properly. When they do engage properly the screw has to be held tight whilst it is done up. This usually involves holding the item being fixed away from the wall to keep the spring tigh against the back of the plasterboard. Since the trunking can't physically be held off the wall without a great deal of difficulty the time element of the job rises expotentially compared to standard fixings the cost will also have to rise.
5. Toggle fixings aren't cheap. A quick glance on the internet returns a result of £3.10 per pack of 10. Times by 8 packets then the total price for the toggles alone is an additional £24.80
   

   The standard way of fixing dado trunking is to mark the height, pre-drill the fixing holes and fix one screw in the middle of the trunking at the correct height the trunking is then levelled and the rest of the screws are fitted. I have allowed 1 day to fit all the trunking, boxes, cut and fit all the trunking lid and run/fit all of the lighting conduit in the building as well as fitting the mains board. If I were to fit the trunking with spring toggles it would take me most of the day just to fit the trunking to the walls.

   The additional labour would amount to approx £125 and the additional costs of the toggles would be around £25. Just to reiterate though that just fitting the trunking to the walls without the lid ir anything else could actually take longer than I've stated because toggles although great for a sort of miracle fixing should only really be used when all else has failed. They are that difficult to fit when using lots of them together.

   My advice would be to fit the trunking using plasterboard fixings. Although plasterboard fixings require a hole as well the hole size is only 5mm and the fixing is larger than the hole size and therefore SELF-FILLS the hole. The plasterboard fixing will stick through the back of the plasterboard approximately 5mm but as I've just stated the actual fixing takes up the hole space. There is some additional cost of around £9 for the fixings and there is some additional labour involved because like the toggle method the trunking has to be temporarily fixed level before its taken down and the hole drilled in the correct places before its fixed properly. However, there isn't the time-consuming fiddling about one has to do to get the toggles through the wall properly and holding them off the wall to get them to tighten.
   
   As I do not know enough about a job like this I only have an uneasy feeling about it.
   
   My initial (perhaps wrong) thought is that surely the screwholes in the PVC trunking can be pre-drilled then the trunking held up level in order to mark where to drill into the PB (I could help holding it up). Is it really necessary to temporarily mount (with screws!) the trunking then take it down in order to makes screwholes as he suggests?

   I am surprised that a hole 10-18mm is needed to fit the toggle bolts, even a cursory look online leads me to think there are narrower gauge bolts available. Not sure what size screws he would have used to fit it in a `conventional` way but 10-18mm seems a huge hole!

   Is the alternative he suggests a good idea?

   With either of these options what would be the correct way to caulk as the job proceeds?

   any thoughts would be much valued. many thanks
   Jose
   

If the man has done this before he is in a better position than I since I have still yet to determine weights of items involved and that would be my criteria.

That said...he said "screws". If it will hold it up and he has installed one of these trunks before....then I say do it.

Making certain that the screws are not so long that they could contact the framing.

The thing is you are using a tradesman who clearly has brains and is quite correct in his preferences. The toggle fixings are the strongest, but his usual customers would baulk at the idea of extending installation time, and his experience is telling him a different route is best. You run the risk of him either charging you lots extra, or not doing it. Same with electricians who love ring mains. In my studios, all the racks are on separate spurs, with their own mcb. A proper household electrician would want to use a ring because it's simpler, less work, and from their point of view - a waste of time. They've also probably worked out that you're not 100% certain, so want to persuade you to change. If he can fix it securely to the PB, his way, just let him do it. I suspect that you could actually use adhesive if you wanted to - although the PB has a paper top layer - surface area wise, the trunking , if it's that wider type would be pretty secure, with maybe just a little extra at the socket boxes.

Tradesmen are not receptive to unusual techniques - and this one's command of English is pretty good and his concern genuine, and that's good nowadays.

Thank you Brien, Yes I realise I have not yet given the crucial info about weight, I understand this is the most important factor. I probably won't be able to ascertain the weight of the sockets per 3M length but I can go out with some scales and weigh a 3M trunking length to get an approximate idea.

He mentions The plasterboard fixing will stick through the back of the plasterboard approximately 5mm`, as the gap between the PB and the OSB (outer shell) is 100mm (now filled with rockwool) I gues that should be OK.

I think he would have installed this kind of trunking before but not in a situation where isolation is a concern. Is it possible/necessary to caulk as he does the job? as he says the fixing SELF FILLS the hole so maybe caulking not needed/possible?

all the best
Jose

All penetrations need to be filled if visible to the naked eye. That said..once this trunk is installed just based on my understanding of materials in general...you should be able to caulk along all the perimeter of the trunk and help to seal any penetrations.

Does that help you my friend.

Hi Paulears,
thanks for your reply , first missed it as was busy responding to Brien's comments when yours came in. I feel reassured that the electrician's proposal does not sound so terrible after all.
The trunking casing that fixes to the wall is 100mm wide but i figured that as it has some weight itself (3m lengths) and will also have sockets embedded in it, cabling plus some pushing and pulling of plugs etc so it will need fixing securely and maybe glue alone may not be best for trunking of this size. Thanks for the suggestion.

we have discussed the issue of radial or star grounding and as you predict, he is resistent and has already given me several reasons why it is not needed. As I am insistent he has undertaken to ask advice from a friend who did the wiring for the studio of a very well known Pop singer (he told me artists name but others may know her electrician so best not to put it out there).
hopefully he will get confirmation that star grounding is what is needed, as you point out my own uncertainty does not help when arguing my case,
appreciate your comments. cheers
Jose

Brien your advice on caulking is a great help so thank you very much! just couldn't visualise how to caulk round a screw! it never occured to me to caulk the trunk perimeters. Should be able to get the builder to do the caulking as he has probably done more of it than the electrician, will discuss with him tomorrow.
Your help and prompt replies are so valuable to me.
Jose

It will be a rare case when a star type grounding system is required and in your case...it isn't needed...and you are to far ahead to concern yourself with it.

paulears ...while I appreciate that you have done some work for others. ..your presence in this case is becoming a distraction. Please read the entire thread when you have time to understand this is more damage control than build.
If you can help with actual hands on experience I am certain Jose can use it...outside of that...you would be a better steward by remaining silent until we get to the point that the young man has some breathing room.

Fair enough?

Hey fellas, I value all advice and comments from each one of you.
I have felt truly helped and supported by Brien's (K metal and other's) timely and knowledgeable advice from my very first post on the forum and derive some insights from everyone's input.
Some truths I must take on the chin (and in the pocket!) but are very helpful even if just for damage limitation.
This forum is great because even when respondents disagree with each other it still helps me crystallise my thoughts and reach my own decisions.
Despite all the errors I have undoubtedly made in planning and execution I am very excited to soon have a space to work in where I can increase work flow and have less domestic interruptions. My needs are relatively modest, working alone, no live drums etc and I anticipate a vast improvement on the 3mx2.6m room I currently record and write in.
I am truly indebted to all who take the time to share their knowledge and experience and help me keep this adventure moving forward!
All the best
José

Hello All!
Brien you commented in a post yesterday regarding my build

`It will be a rare case when a star type grounding system is required and in your case...it isn't needed...and you are to far ahead to concern yourself with it.`

Does that mean I really don't need to convince/persuade/insist that the electrician do it that way?

I am not doubting your advice Brien but trying to understand it as one point I have read repeatedly from many posters is the importance of star grounding to obtain a power supply without risk of mains hum.
In my situation today I have no power at all in the cabin, power will be brought from my house service panel and wired up to a new service panel in the new build, there I will have 4 circuits, one for all audio related devices, one for service (printer, kettle etc), one for the installed lights and one for heaters etc that have thermostats clicking on and off.

what makes me too far ahead to consider or demand star grounding?

Obviously if I don't need it I will save money but my primary concern is to get it right. Would the standard` ring` circuit be right for me?

one more question.. do all 4 of the circuits outlined above need to be star grounded if at all or just the `audio` one?

any guidance is much valued, many thanks
Jose
`

Do it if you want it...I am saying for what you are building...I wouldn't worry about it.

thanks Brien for your reply. Sorry to labour the point. if I need it then I want it but if there are no benefits for me then of course I can save a lot of time, money and hassle by not having it. What about my build suggests that I need not worry about it or don't need it? could I regret it further down the line if I have it ring wired?
regards
Jose

Electrical has nothing to do with the build and only concerns itself with devices using current.

One reason yours isn't worth it is because it will essentially be tied into your house

Despite Brien not wishing me to participate, I'll comment on the wiring. In a small single room like this, you really don't need to be concerned about star grounding. The UK regs and for once, audio requirements are pretty much in alignment. The primary reason in your case for individual circuits is to provide the facility to conveniently switch on/off areas. Handy for things like racks and places where you have lots of equipment fed from a single point. A ring is simply a convenient way of providing diversity in the wiring. UK specs wise having you put 32A mcb in the consumer unit, 2.5mm2 cable - and allowing the use of multiple, higher power devices like perhaps fan heaters - which could be drawing 10-12A each from the ring, allowing other outlets on the ring to have full capacity. The earths will tend to be floating, probably a little over the ground potential - so the feed cable to the studio, which will be steel wire armored stuff will bring in the ground from the house. If the house is modern, the neutral at the intake point is bonded to ground - so unless your studio is a long way away - it's unlikely the ground will cause any grief, and to be honest, normal electrical standards are sufficient. I just like to have a little extra control. A fault in an overcrowded rack could be better protected by a 6A MCB, which I feel is more appropriate given the wall wart power supplies and tangled cables these racks often contain. The fault current required to trip the ring main is considerably more - so in my studio the general wall sockets are on the ring, with the two tall racks and the keyboard areas on individual 6A spurs. All the grounds are at the same potential as the cable lengths are virtually identical and the space small. The benefits of star wired grounding systems only tend to be required when distances increase and the ground voltages drift away from each other, and of course when multiple phases are present. These just don't apply in a small studio. Costs for adding a couple of extra ways to a consumer unit are minimal, and the extra work not that tricky or time consuming. Your electrician will be running the lighting from the same consumer unit, so if you haven't already thought about it, be careful with the types of lighting you install. Probably not really a subject for this forum, but I can advise by PM if you want some info on some things to avoid.

The kind of problems you get with hums are usually caused by some outlets having earths that have a few volts between them - one venue I use regularly has just over 4 volts between the ground points end to end - and audio kit really objects. Within your studio, you won't have this, and I'd not expect a meter to see much resistance at all between any of your grounds. Feeding in a long cable from the house to get some extra power could, of course - but I doubt you'd be doing this. Proper wiring will in your case extend the equi-potential zone into your studio as long as we're not talking about more than maybe 20m or so distance, and if it was that long, I suspect your electrician would be doing some earth stake bonding at the studio end.

paulears

If you can help with actual hands on experience I am certain Jose can it...

That is what I said..don't make me the bad guy here.

Cap fits Brien - Cap fits .........

One thing to add on yesterdays electrics - if you do feed larger racks, occasionally powering up the whole thing with a switch (ideal) or even the MCB itself (less than ideal, but normally works ok, can trip the MCB, even when the load is way below it's protection limit. If you have lots of gear with power supplies then the surge current can be enough to trip - it's an easy fix and fitting type C MCBs is a cure - many ordinary electricians won't have come across this.

In my own studio, I have one floor to ceiling rack, built in, and a freestanding one. I have the very tall one wired into two circuits, so I can if I wish kill just the outboard gear, while leaving the other permanently on, which is a couple of rack mount computers. When I leave the studio, I cut the power to the outboard by habit, and also kill the power to the keyboard area. The ring main is permanently on. The switching flexibility costs little and is very handy to have.

Hello All,
thanks to everyone for your responses and thank you Paulears for sharing your specific knowledge of UK regs etc. I admit to having very little knowledge of electrical wiring (if that isn't obvious already!).

a couple of things in response to your info Paulears...

1) The music room i am having built is approx. 20M from the house service panel

2) I believe the electrician is planning to sink a copper grounding stake close to the outdoor studio

3) In don't have any big racks, device list currently includes PC, 2 monitor speakers, 2 computer screens, audio interface, 2 external hard drives, a valve mic power box, occasi0nal miscellaneous devices eg guitar amp, Zoom digital recorder. Naturally this list may increase over time but it is quite minimal at present.

I am today sketching out a diagram for the electrician (coming Monday) to determine where I want sockets to power the audio related devices and same for service devices such as printer, lights on stands, kettle and heaters (electrically powered oil filled radiators). I will be colour coding the sockets on my sketch to indicate which circuits each socket should be fed from.

from forum responses it sounds like I may not need star grounding, is this right? it would save me hassle and money to have ring circuitry but will insist on star grounding if the `ring` option is likely to cause audio problems.

Paulears thank you for alerting me to the importance of choice of lighting. As far as installed ceiling lights I am considering these options but rather than using LED bulbs I prefer halogen bulbs despite added running costs. The reason is the mounting evidence of risk of macular degeneration and free radical elevation related to use of LEDs, It's about the predominantly blue frequency of light causing the issue, some may think I am a crank but the evidence is out there!

http://www.screwfix.com/p/saxby-amalfi-2-light-spotlight-bar-chrome/6437j

https://www.wayfair.co.uk/Salsa-2-Light-Spotlight-07430-07179-MSUN1797.html

Am planning a total of 4 bars each holding 2 spots on the ceiling distributed symetrically around the central longditudinal beam running the length of the ceiling (please see previous posts for pics etc). have attached a Sketchup of the room to give some perspective.

As always many thanks to all for your engagement in my queries.

cheers
jose

Attached files

Jose - as the floor area is not huge, in terms of pure resistance in the cabling, I doubt it's measurable on a normal meter - where such runs are short and the voltage high. Star grounding is a sensible precaution in large buildings when you're never quite sure where an electrical distribution point actually gets it's feed from. You will, I'm sure have a local consumer unit - so all your earths are referenced to this. If he installs a separate earth, then as long as he takes the usual circuit protection measure sat the house end of things, all should be well. There are a number of possible hazards with multiple earths if you have neutral faults, but many electricians prefer the security of extra grounds local to the outbuilding, and NOT connecting the earth in the SWA feeder. Depends on the distance from the inside consumer unit. If the earth resistance of the local copper spike is low - it's perfectly good enough on it's own. Most sparkies would frown on having both. If the neutral conductor fails, then with a separate studio earth all stays safe, but if both the studio and the house earth are connected, then it would be a path for the neutral current - not a good one, but a path nevertheless.

I genuinely would not worry about risks from LED blue lighting. BECTU, the trade union for the theatrical lighting industry looked into this and the 'blue' lighting question, and concluded that much of the evidence macular degeneration often bandied about was actually flawed. The reason they were looking was that we now use HUGE quantities of blue LED light - output levels have risen significantly so we have thousands of Watts worth of LED blue light, with significant exposure time to the staff (me included - having been illuminated in this for very long periods). The typical white LED has a pretty balanced output now, and from the technical data we deal with every day, the risk is deemed insignificant. I've never yet had a member of the team concerned about it at all, and the material on the internet is (in our view) based on solid ground, but the exposure levels and actual physical impact seem greatly distorted. Tungsten halogen lighting has a spike in the blue end of the spectrum in the 3200-3600K versions of the lamps, less so in the 3000K lamps. The real snags with LED are simply lifespan in practical terms. They do fail, quite often, and the lifespan quoted is a bit of a joke. Worse still is that every batch have a different colour temperature and replacements do not match. In my studio I have some LEDs and some tungsten. The tungsten ones are nicer to be lit with. They do increase the heat quite a bit, and my ventilation system finds it hard to deal with 16 of them. 6 are now LED, but they match badly, and are more patchy in their light output.

Worse still are those that have poor smoothing and are flashing on and off at mains frequency. They all do this to an extent but some you can actually see with your peripheral vision where your eyes are more sensitive to flashing, plus they can strobe with some older monitor refresh rates which make the screens appear to flicker slightly.

I still like tungsten - but getting even lighting with them means you need quite a few of them. In your sized space even a dozen will be a bit patchy - although if you choose aimable ones, then you can concentrate the light where you need it. I can switch mine on and off with no clicks in my audio - and the lighting feed of course comes from the same consumer unit.

The twin fittings you linked to look quite nice - although one does come with GU10 LEDs I note. However, at 5W, these are too dim to be much use, let lone zap you with their death ray. I doubt if 4 (8 in total) will in any way light the room to a level you could comfortably read in. I have 8 in one of my other rooms that is about 2.5 x 3.5m and they're just about ok with 50W halogens - LEDs would need to be the 20-25W type to light the same area. The surface mount device types have pretty poor coverage, and the wide angle ones are just weak. Perhaps you could install the fixtures, and buy a few single lamps and try different ones to see what works best in the space.

If you plan to use more, be aware that you might need to make sure the electrician realises this as power for lighting in my big room is now 800W, with a fairly large surge when they call come on at once. If you have lots, then perhaps 20W lamps might be doable?

Thank you Paulears for your prompt reply, your advice is very helpful and much appreciated.

So if I understand correctly, I don't need to demand star grounding for my room? sorry to make you repeat yourself but as installation is imminent and I am not knowledgeable on the subject I have to be very clear with the electrician on Monday!

thanks too for your thoughts on lighting particularly your experience of LEDs. As the lighting bars take GU10 fittings am I right in thinking I could switch the bulbs for halogens? I have read that they are not always interchangeable so I may need to check with the lighting supplier otherwise

Apart from the concerns in my last post I find the LED light bothers me quite a bit, the light feels too bright and dazzling but cold at the same time, I think a lot of new cars have them and I always feel they have their full beam on even when they are dipped! (maybe they are just halogen headlights, not sure).

I did discuss with the electrician how many spots would be enough for the space (approx 5Mx4M) and he thought that the 8 I had planned would be enough, it is disappointing if they may not alone provide enough light. As you suggest I could add some other individual lights in key areas and/or make sure the spots have enough rotation to to give me sufficient light where I need it. I find I need a lot of light over my desk to see the PC keyboard clearly without squinting. I find the glare of the PC screens dazzles me a bit so viewing the PC keyboard can be a bit unclear if there ar any shadows. My eyesight could be better so I like a wash of very bright light over my desk.

Are you saying that if I have a 8x GU10 bulbs with 50W halogens plus a few floor standing halogen lamps that this could be an issue I need to alert the electrician to?

many thanks
Jose

I would like to hear what Davedog has to say about attempting to establish a star ground system that is feeding directly from a residential main.

Thanks Brien, will await further advice. Just understood it as essential to have star grounding in all cases but from your and other's responses it looks like for my situation I may not need it.
discussed it with electrician but this is clearly not my area of expertise He seems very resistent to doing it that way, a lot more work I guess or maybe he has valid reasons. I am on very unknown territory so don't really know what to tell him or how to argue my case. Just don't want to settle for what suits him unless it is also right for me.
much appreciated
Jose

It's simply that the UK standard is the rule book the sparkies use, and are trained on - 17th regulations. Our grounding systems in the UK, because of our 240V mains have developed quite differently. We have something called equipotential zones, so connections to a house, for example that extend this outwards can be tricky to do - and as most homes have protective multiple earthing - at the point the cable enters the building - taking the building earth and extending it can increase the earth loop impedance - which just means some things like disconnect times in fault conditions can extend beyond those acceptable in the regs. A local ground is most electricians way of keeping disconnect times low. What you are doing is pretty normal, and the part of the regulations that covers your studio build also covers sheds, garden workshops and small domestic outside offices. If the supply is a temporary one - there are very recent new rules that are much, much more complicated. Having a garden party with live music is now quite well legislated for. In the UK, remember that star connection is very rare in domestic properties, apart from the occasional spur from a ring main. Radial circuits, as we call them (star being a US term) are still perfectly acceptable - and are how we feed showers, cookers, permanent heaters and air con systems. UK earthing is quite a straightforward thing. We did for many years have technical grounds in many TV studios and some pro studios, but these now seem to be only in the larger studios with distributed mains around the building. As I mentioned these can be hum introducing disasters, but in your case - your electrician will be right. Spurs for convenience, no other reason.

Thank you Paulears for your detailed response, your knowledge of UK regs and practices is very helpful. What I understand is that I should go with what the electrician is saying and accept ring wiring?
. If is unlikely to cause any problem then it is definitely a simpler/cheaper option.
Part of my difficulty is knowing so little about this subject , because of this I read something on multiple forums emphatically stated by experts and assume it applies to every situation! For that reason I had difficulty accepting the electrician's reluctance.
If these things could be settled with a 'guitar playing shootout' then I would feel on more solid ground!.
Thank you so much!
José

What I think you should do is have him put in the ring, and then ask for a dedicated individual radial to a socket you can use for the audio gear, perhaps with a local isolator switch (like the type you might see on an immersion, with the red light) You could have the switch on the wall in a convenient spot, where the one switch would kill the power in one go. To be honest, mine only gets used when I leave the studio - which as I work from home is a big extension on my house that has two audio rooms and a video edit suite. When I came away in November, I just turned it all off. If he fits a double socket, then he'll probably suggest using a 10 or 16A MCB to feed it. It has no function apart from convenience, and freeing up the ring for those heaters or kettles you might want to use. Worst case is the kettle and the heater - with twin 13A outlets dotted around on the ring, you have up to 32A available. if a fault occurs - which with kettles can happen, your computers and sensitive kit will be fine. With the small circumference, even guitar amps prone to hums and buzzes from less than brilliant earths will be happy with the earths all connected. My furthest distance in my studio end to end is about 16m - and with the proper sized cable (2.5mm2) on the radial and ring circuits, the ground connections are to all intents and purposes identical. My installation is PME - the proper and correct terminology is TN-C-S. This is the 'almost' standard for towns and cities with underground supplies, in single or three phase installations.

The request for the separate supply will probably raise the electricians eyebrow, but perhaps show him this topic, and he'll get it. So treat it as convenience, with the switch just being handy. Cost is likely to be minimal. even a small consumer unit will have enough ways, and the overall load is still well within the capabilities of the feeder supply. Adding one radial, the MCB, isolator and the double 13A outlet plus a modest bit of flat twin and earth cable would be less than forty quid, less if it comes from screwfix!

Is the route from the house to the studio underground or overground? Just a thought that while it's being put in, assuming it hasn't yet how about adding CAT5 and phone cables? Might be handy to have if it's possible? The one thing I'm going to fit in mine is a camera because when I'm in the studio I often miss deliveries.

When I worked in a college, we always had trouble explaining exactly what we needed electricity wise to our own college employed electrician, who resisted anything different from the norm. Once he understood what we really wanted to do, he got it - just to him some of our requests were odd. The UK regs are a bit weird - like I can happily work with three phase 125A equipment, yet I cannot legally put a new light socket in my own bathroom - because that needs an extra piece of paper - which I do not have.

Wow Paulears!! your response is SO helpful and really gives not only very pertinent UK specific guidance but very useful suggestions.

The electrician (coming tomorrow) has asked me to give him a sketch with all sockets colour coded to denote whether they are to be Audio related, Service (stand alone lights, printer/office devices, kettle etc and heaters). he outlined that there are to be 4 circuits as follows

1 AUDIO

2 INSTALLED LIGHTS

3 SERVICE

4 HEATERS

I have attached a very rough sketch of how I will give it to him. I am still finalising what goes where but just wanted to show on this post approx how I see it.

In your response you suggested having the audio sockets on a separate spur of the ring which I will discuss with electrician, sounds like a great idea.

If I understand your suggestion correctly this would mean that all audio devices can be fed from just one or two sockets (via muli power outlet extensions?) with a cutoff switch on the wall (or maybe on the trunking?) rather than the way I have outlined in sketch. It did occur to me when considering cable management that having a wall socket (on surface mounted trunking) for each device could mean loads of power cables going from for example speakers and PC monitors etc to the adjacent wall sockets. Initially I had thought that having multiple power outlets (extension leads) was not desirable (that is what I am living with currently) but visualising having each individual device going to it's own wall socket doesn't seem any neater.

Did I understand your suggestion correctly?

If your suggestion to have a separate spur for audio is not used would the audio circuit have it's own tripswitch in the service panel anyhow where I could switch this circuit on and off ?

I like your suggestion of having Phone and Cat5 wired in at the same time. Not sure if I am too far down the line for this. Right now the main cable into the studio has been put through the studio wall (pic and question about this later!) but has not yet been connected to the service panel in the house. It will run through the wall of the house then externally beside a fence (not buried) all the way to the studio.

Initially I thought I would just rely on my mobile phone for communications (when recording I can receive a call via Whatsapp or similar). Don't really like to have mobile on all the time firstly due to audio interference but also for wellbeing reasons (again info is out there!). Internet would be via a device such as HOMEPLUG or similar providing internet via the mains electricity.

I thought any phone line extension would need to be installed by a phone company technician but if it can be simply wired in alongside the electricity then this is an option I can consider and discuss with electrician (he's gonna hate me!). Once through the studio wall it would be pretty permanent I guess.

The other issue I may need to address tomorrow is the penetration of the electric cable through the studio wall. The builder actually already put that through and caulked it. when electrician came to check site and before I had even realised what he was doing he had pushed and pulled the cable to loosen it therefore ripping out all the caulking and increasing size of the hole! I was in shock and emphasied how that will need to be re-sealed and caulked very well otherwise I may as well have a window open all the time!

As he is likely to connect the service panel tomorrow I need to give clear instructions on how I want the cable penetration sealed. (pic shows how it is today).

Should I instruct that he put cable in a conduit, stuff with Rockwool and caulk again or would just using acoustic caulk on the cable as it is be OK? If a conduit is the way then this could also take the phone and Cat 5?

Sorry to bombard you with questions Paulears, again I am realising how lacking my planning has been in many aspects, partly I have been caught off guard by how fast contractors sometimes work meaning irreversible decisions have to be made very quickly!

I definately owe you more than just one drink for all your help and advice as I do every other person on this and other forums who are so generous with their time and knowledge! Thank you sincerely.

Jose

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This is actually something to run by Brien I think. I've had issues myself in the past that were resolved, but not, in my own opinion as well as they could be. That steel wire amoured cable is amazingly rigid, and if you go outside and tap on it, this can be heard clearly in the room - or at least looking back on my builds, this is how it was for me. I was concerned in this project for sound reduction as a primary aim. I knew this 'puncture would have to happen, but wanted the best solution I could find. The studio had power coming up through the concrete floor, and it was just possible to squeeze around it's entire outside, within the building. I put inside the studio monitors, and amp and CD player with the alan parsons test disk. Then with all the doors shut and the volume cranked up, we moved around the outside with a borrowed sound level meter, and a portable recorder with a measurement mic connected to recorder and headphones. Leakage overall was pretty low - certainly low enough for our purposes, but we did find some leaks, tracked down with the mic and headphones to one of the door seals, and at the top of one of the seals between wall and ceiling. The door seal was just a poor fit, and fixed, and some sealer in the gap fixed the other. Next day, the contactor arrived to fit a fire beacon in the studio. Early in the build a visit from the Fire Officer had raised the concern of how anyone in the studio would know the fire alarm was going off - actually a good question. He simple drilled through all the carefully installed layers and put through the red fire alarm cable. Not sure if they use this in the US, but it's copper tube, mineral filled to create the insulation for bare copper conductors. It can be gently bent and is fire resistant. Trouble is that firstly, after it was fitted straight through, our test revealed a pretty big leakage, and although when sealed inside and out the level went down considerably, low frequencies were up on the outside. Not specifically from that 'hole', but from that general area. Touching the red cable as it exited, you could feel the kick drum beats. Clearly, we'd compromised the isolation between inner and outer and the outside skin was passing the low frequencies to the outside world. Our solution, and this is where Brien's opinion would be useful, was this - I pushed through from outside a plastic tube - 22mm, from memory, to about the middle of the airspace in the cavity. Did the same from inside, and then pulled the tubes apart by about 10mm. The tubes were very tight fit into the holes and the outside smeared in silicone. Once this had gone off, I cut off the tubes parallel with the inner and outer wall. The mineral cable which had been pulled back out was then threaded back inside and we filled the gap with the acoustic sealer, forcing a considerable amount in, which much probably dropped into the cavity - then repeated from the other end. The level of the inside sound escaping was so low before we did the cable entry, it was difficult to measure any change, but the thump thump where the cable sealed into the wall ruined the isolation appeared to have gone. You could still detect a little 'thump' touching the cable, but with a more gentle loop inside and out bringing it back flush to the surface, this was virtually cured.

Looking at your SWA cable I'd bet it's a weak link. Your cable is pretty big - so I'd probably think about something to help not wreck the isolation.

I know you're quite keen on wellbeing solutions, but wi-fi over the mains wiring has been a significant source of RF interference for many people interested in radio reception. Piggybacking audio and data onto the mains is quite an old trick, and it does work - but it's limited in scope. BT solved the home wiring issue years ago with the introdution of the master socket - you can cheerfully add your own wiring inside your property, and with CAT5/6 ruling the world now, if it isn't too late, I'd certainly introduce this into the feed system - even if you don't need it straight away.

A word of caution on using miniature circuit breakers as switches. They're not designed to do this, but many people use them for exactly this purpose at home, and in business. We use them for exactly this purpose in our mains distribution systems in the theatre and events world - it's just handy. If you do wear one out, it's a five minute job to replace it, and they're very cheap - so for me, it would be fine - but the consumer unit is rarely fitted in a convenient place, and they're not really pretty things - hence my liking for a switch.

For your wiring inside to the equipment I personally do use 4 way strips - they're a neat and convenient way of getting sockets where you want them, but are not permanent. If you want to spend a little money, then if your gear uses IEC sockets, then you can get 19" rack mount IEC distributers. I think probably designed for the disco industry - they are a rack full of IEC outlets, usually with a front switch for each one. You can buy IEC-IEC cables in different lengths and you could bring all your cables back quite neatly to a common point. If the equipment also has audio connections, then you could always be mega neat and in the row below the IECs, add a row of audio connectors, then cable tie or heat shrink the two together. I have to admit to being in the not-neat category myself. If you pretty well know a piece of kit will always be in a certain position, then get the electrician to put the outlet exactly there.

I'd love to know if there is a better way of sticking rigid cables through walls - I suspect aircon tubing is the same problem. Solving those flanking path issues but then putting in new ones with the various services doesn't get much coverage - so I'd genuinely appreciate any better solutions myself, as my video edit suite, which is built like a studio, just in case I need to change it's use needs to have a two large rigid cables bringing into it from outside shortly. Two 25mm holes, and rigid, rather than bendy.

Once again Paulears thank you for your quick and helpful response.

I have attached a pic of the cable from the outside fed via a trench into the cavity between the outer OSB layer and the PB, it then is fed through the hole in the 2 layers of PB (interior penetration pic re-attached to this post). One good thing may be that the cable does not have a direct line of sight from inside to out?

From what I have learned by trawling this and other forums it seems like the best way to mitigate this isolation breach is to feed cable into a length of conduit (going as far down cable as possible from inside to out?) then stuffing the conduit mouth with Rockwool (or acoustic caulk?) then sealing the interior hole in the PB with acoustic caulk. It has been a bit difficult to get clear directions on this so advice from anyone who knows would be really appreciated.

Does anyone have an opinion on whether my socket layout plan is overkill (approx. 10 audio related sockets, 10 service sockets and 2 heater sockets)? If I feed various groups of devices from power strips then I wouldn't need so many wall sockets (all to be mounted on trunking). Saying that I can still use power strips in the same way and have the advantage of plenty of other spare outlets.

Changing this plan will probably bug the electrician at this late stage as he may have already purchased the materials but I am sure they can be returned if not needed, just have to get it right for what I need.

Much of my setup in the new space will probably remain the same as I have it now as I often have to record my own guitar or vocals and operate the PC keyboard during the process, positioning is partly dictated by the fact that I am right-handed meaning between takes I need to have right handed reach to the desk. In future I could invest in a remote controller which could free up my location a lot.

Thank you Paulears for your thoughts on use of circuit breaker switches, if I end up not having the audio related sockets on a separate spur with it's own on/off switch then this could be a less than ideal but useable workaround.

Have been further researching using a Powerline network for internet connection in the studio. One thing I have read is that it may not work unless the outbuilding is on the same ring as the main house. I really don't know if this is the case and when I mentioned my intention to use something like HomePlug (Powerline network) he had never even heard of it! I have emailed him to get info on whether the outbuilding and house are on the same circuit but may not get answer before tomorrow. It is very easy to set up but need to know if it will work..would be a stretch financially if I need to bring a Cat5 shielded cable from the house having a trench dug for it.

Any advice is much valued. thanks

Jose

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The reason for the mention of "same ring" is because the gizmo works by converting the data at baseband to something that is modulated onto a carrier - in effect, a radio signal. It's very low power, but this goes a surprising way, distance wise. However, if your house is supplied with more than one phase, then all the RF is on just one of the three. It wouldn;t work for me, for example, because when the large extension was built, it had a separate consumer unit wired to a different phase. I was just lucky that my electrical intake had 3 phase - the orginal owner having had a workshop in part of what is now my studio area. The typical home has one or two ring mains - often ground floor and first floor, plus the lighting and other circuits - cooker, immersion, electric shower etc. The Powerline will work on any of these - so upstairs to downstairs will work, but are separate rings. I'm not surprised the electrician doesn't know about these, they are not really things they install, more DIY stuff.

One mistake I made in the first studio I built was to evenly space double 13A sockets around the room. Clusters are much more useful (if you want to avoid 4 ways) so having at least two doubles together works very well. If the cabling isn't at what they call first fix stage - that is to say, a loop of grey cable coming out at the point where each socket goes, then it's not much of a problem. Changing location once he has done this will take time, and I expect he will charge for everything now, if you've been asking for what he sees as weird things!

I must say one thing surprises me - clipping the SWA cable to the fence like that is a bot of a bodge. Within a year or so, it will be laying on the ground once the water penetrates the timber. Is it your fence or your neighbours? I hope it's yours, because if it's theirs and it starts to rot, they might remove it unaware it's supporting your cable?

One thing that I got from a text book on studio construction was a comment about sound escaping being reliant on the weakest link, and pointing out that adding an extra layer of plasterboard could be pointless if the windows or doors have more transmission though them. It also mentioned about extra glass in windows being pointless if the transmission through the walls was less than ideal. With your original problem being concerned with leakage from the eaves and the airflow up there, maybe your inlet problem isn't worth worrying about at the moment. After all, if he attaches the consumer unit where it pokes through, then you could always box in the consumer unit with an air/sound tight door, which might rectify any leakage.

Lots of things can be done when the installation is complete, while other things it's too late for. Get the power on, make a noise and see how it performs.

Hi all,
Sorry been off the radar today, but I been caught off guard with all the quick decisions had to make with electrician today, today I really learned the hard way the importance of meticulous planning and the penalties for failing to do ! Although I thought I'd spent the last 2 years doing that today was a series of stressful quick decisions I had to make which. made me wonder what I've been doing for last 2 years!! Painful!!
Paulears thanks for your advice on socket placement, am embarrassed by having to make decisions about this at midnight when electrician here at 8am!
Trying to understand whether if I have dedicated circuit for audio (which I will) is the best advice to still run audio devices all from one socket or is that effectively what I am doing when multiple wall sockets are on same circuit? Does having some sockets all on audio circuit mean I can plug audio devices into any of them with no problems?
Paulears thanks for looking at the pics in my last post, the cable fixed to fence is just a leftover from the shed demolished to build this cabin, I knew I should have pointed that out but well spotted! That was a DIY job by previous owner and my electrician would have nothing to do with it!
Right now looking at maybe 8 double sockets for audio to be adjacent to the main working area, does this sound overkill and should I go for power straps and less wall sockets for easier cable management and less cost? Will have non audio circuit for office devices, kettle, fan etc and another for heaters.
Part of being caught out a bit is never having had a choice, and have always worked with what I had.
I'm burnt out tonight so signing off!
Any thoughts from anyone would be much appreciated.
Cheers
José

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Good news is that all your outlets are on the same phase, and have virtually identical earth paths, so you will be able in reality, to be able to plug anything into anywhere - and all your decisions are doing are the physical, practical ones - I've been thinking about my own studios - I have at least a couple of sockets in each that I cannot even remember which circuit they're on - when I hit my switch to kill the rack, there's always at least one pice of kit that stays on, and I have a sneaky suspicion that one of the keyboards is the same - I've plugged it into the ring rather than the individual circuit that was for them! It really makes no difference in a small area where the ring main is usually the circumference of the space.

4 ways are fine when plugged in and left - they tend to be a little unreliable when daisy chained - but again, if they are rarely touched - I've not yet found this kind of thing an issue. Most audio circuits are very lightly loaded anyway.

8 doubles sounds overkill, but I bet they get filled up and at some point, you bring in a 4 way, or two!

Electricians rarely are surprised by requests - after all, they deal with having to put sockets at exactly the right places for cookers, microwaves, fridges etc every day. Yours is not much different - they'll just have tagged you as a last minute customer, and no doubt tweaked the bill! You are the client and can have whatever you want.

hi Paulears and others, thanks for reading my post. your reply is so timely as I am literally in the studio slotting the sockets into the trunking where I want them before electrician gets here!

At the moment I am looking at having...

1) 4xdouble sockets on audio circuit to be behind my desk against front wall (me facing desk and speakers).

2) I then thought maybe another double audio related socket on wall to my right as PC, interface and HDs will be on that side.

3) Again on wall to my right and behind me (when I'm facing speakers) 2xdouble (service circuit) sockets for office devices and stand fan.

3) Then just for flexibility another double audio related socket at back end of the room (behind me to my left-opposite door) , I sometimes use a Zoom stereo recorder for recording congas etc so be handy to have an easy choice of location to record them with no trailing leads.

4) 2xdouble sockets (service circuit) on the far back wall behind me (where GIK monster trap will be) for extra floor lights, kettle, LED strips (for colour splash behind sofa)

Planning to have 2xsingle sockets for 2 oil filled radiators but unsure where these should go, don't want them too near my 5 guitar stand or the main desk or PC area.

How does this arrangement sound?

Sorry to not supply sketch right now as I am rushing a bit but please let me know if my description is unclear.

Will try and get back shortly with sketches etc

Thanks

Jose

I think the final socket arrangement must be yours - sounds fine, but only you can know if it will work.

One question - totally un-recording related. Oil filled radiators. They are pretty good for keeping hot when switched off, but take ages to warm the room. I have one in my edit suite, and have a fan heater too - for when I need to do some work I've not planned for and the room is freezing. I leave the racks of gear on, and the two computers permanently on in the audio studio - this prevents it ever getting too cold, but that room also has a normal radiator in it too - but often, the heat from the rack & computers - which runs at around 400W consumption - is actually enough for all times apart from the coldest periods. One thing you need to consider is condensation - your room being acoustically sealed is also going to be pretty good at keeping heat in - so in winter, entry and exit can let quite a lot of moisture in, and it will condense. Depending on your situation, you could need a dehumidifier at some point. Heating up and cooling down can make this a little worse.

Great point Paulears, in the light of what you are saying it is definitely a good idea to have a dehumidifier and maybe instead of having 2 radiators have 1 radiator and 1 fan or halogen heater that heats up quickly.
Have been doing my own head in trying to get the best plan for sockets etc. Your clarification in your last reply about being able to treat all 'audio' sockets the same as if they were on a multi power strip is really helpful as it means I have more options, may as well have plenty of sockets on the audio circuit as am bound to expand my setup moving forward, can still use power strips if needed but for the extra it costs for the sockets may as well keep options open.
Thanks so much
José

Hi everyone,

Back again with questions I shouldn't be needing to ask!Hope it is not a problem that I also posted this on J sayer's forum but am just eager to get some guidance if possible.
Am at a stage of my construction where I am facing some imminent decisions that by rights I should have addressed ealier in my planning stage but I am where I am and for that am feeling pretty self-condemning! following on from recent posts I need advice on a couple of key issues.

Floor will soon go down, currently there is a concrete slab with DPM ontop. next will go 50mm Celotex then underlay and laminate flooring ontop.
befor getting to next stage I have discussed wth builder (not studio build specialist) about addressing the 25mm gap between the concrete base and the walls (2x15mm PB). He seems to think this gap doesn't need caulking but to me alarm bells are ringing loud!

According to my research on this and other forums it needs backer rods pushed into all gaps then caulked thoroughly to fill the gap fully, some gaps may not fit backer rods so just fill with caulk in these cases?

Am I correct?

I assume acoustic caulk is best but any other suitable alternative suggestions welcome.

Other issue ringing 120db alarm bells is the penetration of the electrical armoured cable which will bring power to the structure.

The original feeding in of the cable has not been done correctly as far as I can see. cable was brought in via external trench then into the cavity (now filled with 100mm Rockwool) between the external OSB layer and PB layers. It was brough in before the PB layers were put up and not line of sight penetration (came from below then up to penetrate PB at higher level) but was not put in a conduit so therefore no decoupling of conduit sections.
pic shows a massive hole with cable penetration showing, also visible through the hole under the plasterboard is the top of a resilient channel. Have included pics and a simple sketch (PB is fixed to studs but these not shown in sketch)

Discussing with electrician how to seal this to the best degree possible prior to installing service panel at that location I outlined that the cable should be threaded into a conduit going down as far as possible then conduit stuffed with rockwool (down into conduit as far as possible) then sealed with caulk as far into conduit mouth as possible and where it appears at interior surface. He says he can't do that!

I am aware that this is a solution far from ideal but is it the best possible remedy to what I see as an appalling situation?

Also notice that inside the hole the 2 flanges of the visible RC have plasterboard dust/powder in between which will have to be got out to avoid short-circuiting the isolation provided by the RC.

I also assuming the empty space around the cable now visible behind the PB needs to stuffed full of RW?

Any advice would be very valued
thank you
Jose

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