Another workshop insulation question

Does anybody have any experience of this stuff ? Seems like a U bargain. My bargain pallet of Kingspan is likely to be a bit scrappy so an extra vapour barrier could be useful.

Cheers,

Rod

OTT as just a vapour barrier to compensate for damaged foil face, polythene would do for that.

If you want to use it's additional thermal properties then to get the best out of it it then you should not squash it up so really needs to be battened and counter battened. One I prepared earlier before, during and after

I thought as a postscript to my involvement in this thread I would just bring my thinking and what has happened up to date. My workshop build happens in a couple of days, but on returning from a few days away, I found all my plans for the electrics had to be thrown away.

Insulation is going to have be a main part of the build. The Part P Nazi police in this area seem to be having a go at people with power in their sheds or wanting to do so. A simple installation like the one I wanted which is four double sockets on a ring main and a lighting circuit through a small consumer unit and MCBs is no longer acceptable. Firstly the Building Control Police have to be notified up front with forms and drawn plans before any work is undertaken, I am charged £300 for the privilege of some numpty public servant saying yay or nay, if yay then work can commence. The on cost is then going to be several thousand pounds as the workshop will be 30 metres from the house. I have to have a large steel wire armoured cable buried to a minimum of 750MM (30inches), special yellow warning tape buried just above the cable I cannot export the "PME" house earth, all earths must be isolated at the house end and only connected through a "TT" earthing system at the shed end, it goes on.

However as we have external sockets anyway installed at the time of rewire (fully approved and certificated) on their own ring I am getting a thumping great site extension cable (commercially made and available to alleged idiots like me) and plugging that in using extensions internally in the workshop for my needs. Maximum machine motor 600watts, LED lighting and still have capacity over for a bit of heating as I am told I can use up to 3125Watts, the rating of the extension and the Nazi BC police admit they can do nothing about that. I can only use one machine at a time, I am not clever enough to use the mill, lathe and drill press at the same time with all of them fully lit, oh sorry forgot the bandsaw.

What an insult to all of our collective intelligence by people whose knowledge of O-level physics is probably negligible. So much for safety.

regards

Ian.

Except anyone with any sense would plan their workshop size, location with respect to boundaries, location to the main property and the method of construction to ensure 'planning' and 'building regulations' did not apply. Then there would be absolutely no fee to pay for anything.

The an earth has to be exported along the SWA cable from the head end, it will almost always be the PME earth connected to the armouring to ensure suitable fault protection and fault clearance times for the cable. The cable merely has to be installed to prevent any damage. Burying is not always required, but if it is then burying has to provide some warning to anyone coming along, commencing a dig and encountering the conductor 'hidden' just below the surface. The cable depth of burying is only specified for the main incoming feed into a property and network operator feeds in the carriageway and pavement. Anything on your own property with a sub main or individual circuit is not prescriptive as to cable depth. There are recommendations but that is all they are.

In addition this 'exported' earth then has to be totally isolated at the outbuilding and a local earth provided unless you have means of adequately ensuring against rise of earth potential from a fault or lost neutral which is what the equipotential bonding is there for in the main property.

Cabling with a flexible extension cable can easily lead to a situation where a fault occurs and is not cleared in time, leading to a fire hazard and a shock hazard when metalwork within the outbuilding installation rises above the potential of the local earth. Just plonking an RCD in the installation at random locations may not be enough.

It might all be viewed as just 'part p' and denigrated in some / many eyes but in reality an outbuilding electrical installation requires a common sense properly engineered electrical installation that in the case of a new installation meets the requirements of BS7671 or if you want to be pedantic the equivalent IEC requirements.

Fail to comply either as a 'pro' or an amateur and it results in injury and you will almost certainly be prosecuted even if you have subsequently moved house.

But your biggest problem was wanting to build something that requires Planning and Building Regs. 15m^2 timber or or 30m^2 brick / block / stone should be enough for most 'home' workshops. If you live in a national park or other location protected from development then you have some sympathy.

Forgot to add you can get an electrical installation in a structure outside the remit of building regulations (separation / use etc)   'certified' by an appropriate person / organisation without any building regulations application being made. 

https://electrical.theiet.org/wiring-matters/issues/51/part-p-third-party-certification/

Edited By Martin 100 on 08/10/2018 14:10:00

Sadly not so Martin. The building is nominally 3 metres by 4 metres and only 2.35metres high at the apex.. It will stand 1 metre from both the boundaries it is adjacent to of our land. All NOT needing any form of building regulation notification except the electrical installation it would seem.

I had planned a proper installation internally with metal clads and conduits and the correct cross sectional cables, earth spike, consumer unit properly populated etc.. Once the "professionals got involved before my holiday to prepare the final specs and quotations this was the end result. The first demand was a submission under Part P. cost £300 in this area for public servants and it is on their own paperwork. Then the four figure sums started to come out. Then no sign- off unless the correct depth of burying and pea gravel, sharp sand, warning tape and so on and a completely OTT 10mm sq each conductor in the SWA cable..

No longer interested. A suitably sized "site" extension cable has been purchased, as said 58 quid today. This can be plugged in when I want to work and run out and unplugged and put away when I finish unless of course one of the experts wants to to tell me that is also illegal as ther will be nothing fixed in the building even the lighting I have designed to hang off cup hooks now,. It must therefore be illegal for me to use the external sockets to use my strimmer, hedge trimmer and drills fixing hanging baskets to the masonry and so on..The external sockets are already part of the rewire certification. Nothing else is needed. I won't bother trying to do things properly again that's for sure.

Thank you for your interest.

regards

Ian

Edited By The Oily Rag on 08/10/2018 19:04:50

Ian, what part of the country do you reside in? It would seem that your planning and building control departments are over zealous to extreme. I live in East Sussex and our building control has apparently been privatised with a company located in Tunbridge Wells being the contractor concerned, I might add that I live some distance from them just outside Eastbourne, fortunately do not need any services from them and if your experience is anything to go by I hope I don’t. It is hardly surprising that people tend to steer clear of official certification, it is counter productive for a safer environment.

Dave W

If you think that running electrics to the shed is ludicrous try getting the go ahead to lower a path so that you can drive onto your property and not block the road with your legally parked vehicle.. LOCAL COUNCILS..

Once I saw a figure for the impact that all the people who had dropped kerbs and put hard surfaces on their front gardens in Birmingham had caused in terms of flash flooding before planning controls were brought in.

It's not just little positive actions that can add up to make a difference!

Neil

Ian, as mentioned above about third party certification, the electrical installation can be officially self certified by an electrician registered under any one of numerous official 'independent' bodies For instance NICEIC or NAPIT or Elecsa or Stroma (plus others too) The actual cost to the installer is so insignificant (about a fiver) it is totally lost in the labour and materials and rarely even becomes a chargeable item.

The conductor size proposed might appear 'over the top' but it might be proposed for extremely valid reasons. No one would deliberately use oversize cables as they are a pain to install.

One thing is clear, with a building where the construction of the structure is outside the remit of building control There is absolutely no need to pay ANYTHING to building control nor indeed for them to be involved at all. Plus I doubt there is now a building control department anywhere in the UK with any valid expertise on electrical installations.

You appear to prefer to circumvent the requirements for a fixed installation by using an extension cord. A 'new ' installation must legally meet the basic safety requirements, they are a couple of paragraphs specified in part P and are met by complying with BS7671 or by an equivalent IEC standard. That requirement is usually ensured (in the case of those not appropriately skilled) by employing someone competent and who can self certify, not by employing someone to install and then paying hundreds of pounds to building control (only for them to employ a subcontractor)

For those appropriately skilled and qualified that deem part P certification an insult we, as ever design, install and test our own installation to fully meet the requirements (and some of us would if necessary be prepared to argue our case in court)

Your extension cable is not and never will be a safe substitute for a properly designed and earthed outbuilding installation. It could, regardless of your specially installed outdoor sockets, kill you or someone else. That situation may arise as a result of issues occurring outside the boundaries of your property and totally within the remit of your distribution network operator, and while your installation within the house will, if properly installed remain safe at all times, your extension to the outbuilding and particularly exposed metalwork on any machinery will not.

As dirty harry, the well known electrician allegedly once said, do you feel lucky?

One thing I will tell you about Martin and is a cause for much of my scepticism of Electrical regulation and that most of it is designed to make a lot of very unworthy people a lot of money

Some years ago we had a new house, purchased when it was just a hole in the ground and being built by a well known national developer. The gas supplier could not maintain a stable supply to the whole estate and all the houses had to be electric only (and this was in a well known South coast city I hasten to add not in the sticks). Additional insulation was installed and the house granted a "Medallion Award" After two winters of not too high a comfort we asked the Board as it was then to come and survey the house for us to upgrade (at our own expense) the heating installation. Board expert surveyor came , we were under utilised (her words) and the installation capacity should be doubled meaning we could run at about two thirds capacity in the efficent parts of the performance curves.

Despite them being the most expensive we gave the work to their own contracting company feeling we would get a better job. Two days after completion I returned from work to find that our house had almost burned down. The outlet for one fixed appliance so recently supplied and installed by "experts" had its outlet reduced to a blob of melted plastic, the wallpaper in hall and staircase charred from just above skirting board to ceiling and charring damage to the ceilings.

All lower tariff circuitry had blown out. A simple check of the whole of the house with a multimeter (of some quality) showed that everywhere there was a dead short between the earths and the incoming neutral. The duty engineer at the Board just gave me a n umber of a call out cowboy to come and make the house safe. This cost over half a weeks wages at the time just for the fitting of a couple choccie blocks. When senior management fo the Board arrived next day along with expert technical supervisor I was told thatr it was now standard practice with all new builds that there was no earth at all. All house earths were now bonded to the incoming neutral and hence at my protestations admitted that they now run just a two wire system and a dead short would always exist between earth and neutral.

At my comments about the uselessness of IEE488 regulations then they just shrugged their shoulders, suck it up its cheaper for us to distribute this way. They redecorated, repaired and replaced as necessary and paid me money effectively to keep my mouth shut.

Never trusted electricians and electrical "engineers" since.

Experience is a very wise teacher.

regards.

A few years ago while having a new digital meter fitted, the engineer was explaining ( or trying to) that the Neutral is effectively the 'Company Earth' and that the House earth was belt and braces with any potential difference being between the Live and Neutral / earth.

What you are saying here seems to corroborate that statement.

Ah, sounds as if they installed a GPIB cable instead of a mains supply. That would explain the fire. Was it ever described as IEE488??

If the neutral and ground were NOT connected together, I'd be very worried. The neutral would be able to float anywhere between ground and 240Vac which wouldn't be fun. Whether the neutral is connected to ground back at the substation or at the premises shouldn't matter a damn. Various schemes are allowed.

Murray

Edited By Muzzer on 09/10/2018 18:44:16

Here's my pallet of Kingspan, nominally 50mm. A few are 40mm, which have gone on the party wall and there was one at 60 which has gone on the ceiling.

It's been quite awkward moving around the kit but the weather has been benign so most of the cutting has been done outside.

Two walls and the ceiling finished so far, with much help from my glamorous assistant ( Mrs J)

The softwood ply came from my neighbourhood bargain DIY store at 12.95 a sheet - Fairly crappy and It feels a bit damp but I guess it will dry if I keep the doors open. They delivered 20 sheets for £5. The Kingspan has been fitted between 50mm square battens screwed to the wall and fitted between the ceiling rafters (or are they joists?).

Cheers,

Rod