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  1. 4 points
    22 to the UVC. 22 from UVC to manifold. 15mm to shower / bath from manifold. 10mm elsewhere. 22 or 28 for the ASHP depending on MIs
  2. 2 points
  3. 2 points
    Yes. Should have started already as we've done demolition and recovery of materials from the original house. I'll have to do it retrospectively. Sounds good - after I posted I spotted micro optimisers that replace the control boxes in Perlite panels and seems like a good option. Using them brings the whole installation in at about £5.5k. FYI rear view of house attached. Won't be putting the skylights in to the bedroom outshoot, so have chance to fit 4 panels on each side. Main roof with dormer faces due south. Other option is the flat roof, but I'm not sure on the aesthetics.
  4. 2 points
    More generally, and not being any form of expert, I found that having a (paid) M&E adviser in the planning stage of my build has proven to be invaluable. A few hours of hourly-rate advice from an expert has impacted on so many areas, not only the choice of a heating system, but everything from penetrations through my concrete raft, to lots of other issues that had knock-on consequences elsewhere. I had picked up a great deal of knowledge by avidly reading this site (thanks everyone!) but that adviser was able to assist in unpicking all of my half-thought-through ideas and string together a coherent concept. I considered it money well spent and my architect complimented me on the approach.
  5. 2 points
    Yes. As long as it’s a dedicated ‘high flow’ unit it’ll do the job. Most you can expect in reality is two “ok” showers simultaneously, or one excellent shower, but two is possible. This is remembering that an instant hot water heater, of whatever fuel origin, is ‘cold mains dependant’, so if during the two ok showers someone flushed the loo, you’re going to know all about it. Same if any white appliances are set to run whilst you’re showering that would be a disaster. Discipline is number one in this scenario, so with unsympathetic teenagers in the mix I’d forget anything instantaneous here @MrsDeS. Boiler + thermal store is what I’d fit here, or a bigger than necessary UVC ( unvented ( mains pressurised )) cylinder, but you’ll then suffer the longer term ownership issues when said water thieves fly the nest and it’s just you guys there. As you have UFH ( and why have you oversized the rads if you’re on gas not a heat pump ?!? ) I’d say fit the TS ( thermal store ) as it’ll give you a buffer for running the UFH and give you your condensing range, ( which you won’t get at very low temps btw ). Downside is you need to keep the TS hot all summer for DHW ( same as you would with an UVC, but typically hotter than ) so losses need to be considered and managed. Best way is to put it in the airing cupboard to warm your trollies all year round. Cold mains needs to be surveyed before deciding, as you can’t get a pint out of a half pint pot, and you’ll probably need to have all the cold mains in 22mm and pipe accordingly for your needs.
  6. 1 point
    One year on from first install, I set about servicing my MVHR today. Aside from cleaning and replacing the filters, this is the first action I've undertaken with the MVHR. First off, the front cover is secured in place by a series of screws with a mortorq head. Quite why they have used these rather than the Philips head used elsewhere, I'm not quite sure. Fortunately, I had the appropriate bit, but unfortunately, the screw heads are that soft that one of them stripped. Gravity came, in a way, to the rescue. Whilst I was considering how to proceed, the cover fell forward and broke the flimsy plastic fixing through which the screw secures the cover to the body. So, with front cover now off, I pulled out the heat exchange core ( its a very snug fit so needs a firm pull). I anticipated that there would be some residual water / condensation in the core as it wasn't long after morning shower time. Best advice is therefore to keep the core level until you are somewhere safe to drain any water out. I washed out the core using the shower, and there was a bit of dust / gunk etc that came out of it. To dry, I left it outside and the wind did the rest. Aside from the water / condensation in the core, there was some black mould growth where any water would normally drain out of the core into the condensate drain. Bleach and a toothbrush dealt with that particular issue. Having dealt with the core, I wiped down all of the internal MVHR core housing and duct outlet surfaces. Generally speaking they were pretty clean. The summer bypass, which consists of plastic louvered fins, required a bit more cleaning, as the fins all had a coating of dust that had stuck on. Likewise, the extract fan impeller blades were covered in a coating of dust that had stuck on. I'm guessing that in both cases, the moisture present in the extracted air made the fins and impeller blades damp enough for the dust to stick such that it wouldn't simply brush off. The dust deposit did however, wipe off fairly easily. Finally, I checked the condensate drain, making sure it was free of blockages. After cleaning the two general filters, I slotted the heat exchange core back in, replaced the filters then refitted the front panel. Fortunately, despite the damage described earlier, there were sufficient screws left to secure the front panel and seal the heat exchange area. In summary, easy enough to self service, just be wary of the screws securing the front panel.
  7. 1 point
    Ok so see the big nut just above the knackered zone valve ..?? Undo that, and remove that you will allow the rest of the pipework to move - the isolator should release then.
  8. 1 point
    So are you basically asking whether there’s any cost saving in upgrading as opposed to a new build?
  9. 1 point
    I had great price and service from Plug-in Solar, I think they're a reseller for Midsummer, and didn't have any issue with delivering to NI.
  10. 1 point
    It was suggested this might happen. One school said gravity would overcome the potential issue. Another predicted it to a tee. Seems all too familiar for some reason... 😉 VID-20200528-WA0008.mp4
  11. 1 point
    Ideally you'd want any connection downstream of a loo to be in top third of pipe. I'm sure it would be ok where it is but just use judgement
  12. 1 point
    What about an old hearth? I got two lovely pieces of marble for £5
  13. 1 point
    Can you tell me why you put a link up that is in German. Good god man I struggle with English.
  14. 1 point
    Could you not use an offcut of granite/quartz? If you have a local supplier they will have offcuts or look on ebay etc. Or maybe a piece of toughened glass might look good, particularly if frosted.
  15. 1 point
    How about using some of the solid laminate from the likes of Worktop Express? It's very nice stuff (a friend installed in her new kitchen extension recently) and would double up perfectly well for this purpose.
  16. 1 point
    It is the inverter that sets the maximum generation. My inverter is rated at 4kW but with the output current limited to 16A. This caused the DNO to initially reject my application, saying it was over the limit for automatic approval, that was resp;ved when I sent them the data sheet stating the current limit.
  17. 1 point
    Microinverters are convenient (maintenance wise) placed inside the loft, but should be as close to each panel as possible (ideally just using the short retained flylead that comes with each panel, no extensions). This is awkward if doing a "warm loft" as it means lots of penetrations through the thermal & airtight boundary on the pitched roof. For this reason we're doing micro-optimizers on the back of each panel, then we'll chain them to have high-voltage DC connection to the ground-level inverter.
  18. 1 point
    They sometimes have a screw at the front at the base that winds the rear leg up / down. RTM.
  19. 1 point
    Depends on whether it’s all being squeezed down one 15mm pipe which is T’eed off repeatedly, or through well thought out and dedicated radial supplies. The difference that can make to the same cold mains is significant. Most combis have 15mm inlet & outlet whereas an UVC / TS have 22mm so can convey much more water / have lower paths of resistance. Designing a new system from scratch makes this possible, but solving a retro fit is a bloody nightmare as you’re constrained by the existing pipe work etc.
  20. 1 point
    Hi Just signed up to BuildHub as we are in the middle of buying a steel framed barn that has full planning permission to convert to residential. This is our first full self build, so no doubt we will be asking lots of questions along the way. At the moment we reading lots, trying to gather as much information as possible. So if anyone has done already done this type of build and has any advice it would be welcome. We are in Buckinghamshire so any recommended Builders/Designers or Architects who have worked on this type of build would be good. Many thanks Martin
  21. 1 point
    Another option could be a floor standing high flow combi , ( Worcester Bosch do a tidy one iirc, used in a lot of B&B’s / small guest houses ), and a 2-300L cold mains accumulator to fortify cold mains delivery, but you’d still need a small / medium buffer to compliment the gas vs UFH situation to get your condensing range reliable. The issue is the length of hot water draw off duration stated in the OP. No accumulator will defeat that problem, unless you’ve a room full of them.
  22. 1 point
    Why the oversize rads if you’ve gone for a gas boiler ..? Standard size will be fine, blending for UFH temps (35c or so) should be done by the manifold. Don’t be tempted to run the rads off the UFH manifold ..! Oversizing is normally done when you want to use ASHP. In terms of your hot water, I would not bother with a combi as even a 35Kw will struggle with a pair of showers running - consider a 500 litre UVC, gives you the option to run it hard before the first showers but the tank will stay hot enough to keep you going through the day (with potentially a mid morning boost) Other option is a thermal store as it will allow you to run everything off one tank with just a heat only boiler but that will put more heat into the building 24x7x365. Upside is that if you have Solar PV you can dump to it year round and not care about it being 85-90c as it is just more heat held.
  23. 1 point
    You'll get a technically correct answer from others on here @MrsDeS. But the results of heating stuff up depend on how people perceive those results. On how real people feel in situations relevant to them. I'm suggesting, based on a trustworthy estimate, you over-specify by a bit. How big's that 'bit' then Ian? Ask another plumber - one who hasn't specified or quoted for the system. No conflict of interest that way.
  24. 1 point
    Thanks @PeterW, very helpful. @SuperJohnG, we are on a surface water supply from a burn. The big cylinder is the iron treatment filter, as we have a high iron level. Not sure we ended up with the best bit of kit here as it doubles as a water softener which we don't need. I think I can get away with out using this part of it. I went through a local company in Inverness. They double checked what I thought I needed. Happy to pass on costs for comparison if it helps? Agree on all you say about the plumbing. I too work in hydraulics (more on the design side), so happy with bigger stuff generally! As this is so important to us, I don't really want to outsource the fitting. If it ever breaks or needs work, I need to be able to repair relatively quickly so being able to put it together and take it apart is more important to me than aesthetics (so long as I can get it functional).
  25. 1 point
    I am at the stage of discharging planning conditions so I can start. It has taken almost 12-weeks and I have only just had the first one discharged (of nine). I have just sent them a two-week "deemed discharge" notice for the rest, which might focus their minds (… or might not). That's an indicator of how slow things are in my neck-of-the-woods (Cambridgeshire).
  26. 1 point
    I would be inclined to use copper compression everywhere - you will be able to modify it easier and unless you’re sure on push fit, the Tectite copper fittings are once only unless you buy the expensive ones. For your pressure gauge you need a 1/4BSPT hexagon bush, threaded into a 22/22/1/2 female tee A decent thread sealant is always good, and spanners that fit along with a nice set of pipe pliers to hold the fittings straight. I’d assume the plastic female stuff is 3/4 BSP - be careful not to strip it with brass fittings and always try and find an adapter with a flat face or shoulder when going into plastic and check the depth of threads too.
  27. 1 point
    Everyone is being very helpful re the details here, but before going any further can I make a few points. 1. Garage doors provide a pathetic level of insulation and air tightness. If you take a picture of one with an IR camera, much as the centre of each panel is insulated, the edges are not. Nor is the frame etc. The amount of heat you lose through a cold bridge at the edge of your slab will be inconsequential to what you lose through the door and the door frame. 2. I thought at one point that this was a good idea, but my research suggested that heating your garage and putting a damp car in there is bad for it. If you plan to use it as a heated workshop that is different, but if you plan to put the car in there it is a bad idea. 3. How much time do you actually spending the garage? My unheated integral garage with a 40mm insulated door drops to around 10C when it is cold outside. This is much better than keeping a car outside and fine to nip in there to put the trash in the bin. So again unless you plan to use it as a workshop and spend hours in there it would be a lot to spend for not a lot of use. Of course if you want to it is up to you, I have been thinking of plastering and tiling mine as it would look nice but then I keep telling myself I don't really need to. So far sense is winning.
  28. 1 point
    I think I’m going to do something like this, I haven’t put a lot of thought into it but it’s sort of what I’m thinking.
  29. 1 point
    If you can persuade the zone valve to actually turn, with a spanner on the flat of the actuator and once turning give it plenty of exercise until free, then just change the actuator head if it really is burned out. What makes you think it is burned out? You can't always test the Honeywell heads off the valve base as they have a habit of the gears disengaging and them going twang, which may make you think it is faulty when it is not. So get that valve body turning and try the actuator head on. If the only issue with the "bypass" valve is it is leaking, put a bucket under it.
  30. 1 point
    That is an 82p isolator valve - just undo the nuts and replace with a lever valve of the same size. The nuts and olives can stay in place, good squidge of LS-X for ultimate bodginess and you will be fine. I would leave the zone valve in place and wedge it partially open - no point in changing it unless you need to, otherwise it would be a 22mm lever valve for me and a 28/22mm compression reducer and a short length of 22mm copper pipe.
  31. 1 point
    Why do you want to do anything other than fix it? Why change things? The "bypass valve" is an ordinary service isolator. Easy to just get a new one and replace it. BUT is should be an automatic bypass valve. That only opens when you get a certain water pressure, typically when the pump starts but in the time before the motorised valves actually open. Likewise that's a Honeywell 2 port valve. An air lock would not physically stick the valve, it is broken. So replace it with another. If you want to do cheap, the cheaper Tower ones are pretty much a copy of the Honeywell. And since you will just be changing two things like for like, there is really no plumbing to alter. However you will be re using the olives on the pipes, so give each a few wraps of ptfe tape to increase the chance of them re sealing. Just replacing the broken bits will make the system operate as it should and save you having to bodge the wiring to frig it. Do take care to do a drawing or photograph the wiring of the old zone valve before you remove it and make sure the new one connects exactly the same. Possibly the hardest part of this will be finding enough slack in the pipe work to pull the pipes apart a little to get the old valves out and the new ones in.
  32. 1 point
    Piling is a very interesting topic. As I (imperfectly) understand it, piles of many types - are driven, screwed or compacted to whats known as a Refusal - simply a calculated back- pressure beyond which its not worth doing any more work (called the Working Load I think, maybe wrong). Refusal sometimes therefore varies by position. In our case one of the 64 piles just shot into the ground - to Refusal at about four meters. Most refused at a bit over three meters. One hit an incursion of rock. Because it was the last pile driven I could hear the difference in the cadence of compaction. And the ground really shook. The rest sort of slithered in. Just for completeness, @eandg, piling cost us £6500, Groundsure test , about £2500 ish, and one critically important letter (email) from the SE - one that together with a bit of research on my part and help from BH members saved £17000 (yes 17K) . Hillard Tanner saved his fee many times over. Top bloke - and his partner Nick Bailey. Ours were tested to 2.5 times the static load. One or two of the piles achieved 3 times the static load and one a little more.
  33. 1 point
    £10 on e bay. Glass suckers. (See my advert) hook in ceiling then some type of small block n tackle 3-1 ratio will work and not cost much.
  34. 1 point
    Saw this on FB and thought of you @Ferdinand
  35. 1 point
    I really like these - could soon diy one with some 50mm pipe https://www.supragarden.com
  36. 1 point
    heres another way maybe if your man made long thin versions of these then you don,t even need a crane and just hand fill the holes? another way --wonder if blocks this size are available in uk
  37. 1 point
    Well, Architects are quite happy working in unitless and qualitative measures; see also visual weight of a design, degree of overbearing or overlooking on neighbours, harmony, speaking the local vernacular, feelings of space and light, etc. To be honest the vast majority of the population are also quite tolerant unitless and ill defined measures. It's just in the more obscure corners of the internet you find the folks (some would even say, pedants) that get het up about it
  38. 1 point
    Always use JTM Plumbing for bulk online orders, and Screwfix for bits. https://www.jtmplumbing.co.uk/ Is this DHW etc..?? Anything non heating related you can use non barrier. Oh, and when running it through walls, buy some lengths of 21.5mm overflow pipe and drill 22mm holes - sleeve the pipe through with this. Don't forget some decent cutters ...
  39. 1 point
    @scottishjohn if you look carefully you will see there is 50x50 trunking already installed all around the cabinet. Where it's needed I have installed it. As for running cable in conduit, you still have to put the conduit somewhere. If that "somewhere" is in the EPS then it will still derate the cable, albeit not quite as badly. From recollection (I don't have the 7671 guide at home, cos it's living at site at the mo) clipped direct gives 27A limit, in conduit in EPS would give 18.5A or thereabouts (although some argue that the derating isn't valid if you're talking about conduit that is also touching the plasterboard, the regs don't give a firm steer either way so I play safe). Besides which, the lifetime of the mains cable for sockets (which is all that I am chasing into the EPS anyway) is probably longer than my remaining years on this planet, and sockets don't tend to need additional cables pulled 😁
  40. 1 point
    We have approx 1200m of LSZH twin and earth installed in our ICF build. Costs a chunk extra, to be sure - first, because its roughly 30% more expensive to buy 6242b cable than the same thickness of the usual grey 6242y cable; second because you're embedding the cable in insulation, you have to derate the cable. That means you end up running radials and rings in 4mm2 cable instead of 2.5mm2. Here's an idea of the hell I am in with cabling... That will one day be a home automation system, with DMX controlled lighting and power circuits, and either Loxone or Unipi managing it all. For now, it's just my nightmare that comes true every time I visit site. 😭
  41. 1 point
    Don’t forget if you’re having a row of boxes, or boxes above and below each other then you need a decent spacing. 35mm is good - happens to be the depth of a back box too so spacing is simple ... Just make sure the noggins and socket locations have enough space for them
  42. 1 point
    Just a note, my plasterer wanted the front edge of the metal back box nearly level with the finished plaster otherwise he said the plaster could crack around the hole when fixing the front plate.
  43. 1 point
    height between 450mm above floor to the bottom of the box & 1200mm to the top of the upper box. I don't put them any closer than 150mm from corners. Decent size noggins so you have some wiggle room; screw inplace. 47mm back boxes - easy wiring guaranteed. Leave the box out slightly from the timber frame etc so when boarded it sits back slightly from the boards. They take some time to do for a whole house......
  44. 1 point
    We did a comparison between a number of systems and the Pex-A systems were not a patch on the JG or Hep2O systems for a number of reasons. The key ones were : - hot water (above 30c) pressure capability is significantly lower than established systems - warranty of 10/25 years depending on systems vs 50 years (from Wavin) - interconnects between new / old requiring specialist fittings - cost of installation / tooling and skills to install were more complex - ability to decouple or remake joints or change layouts was restricted with press or weld systems. - long term availability of spares / replacement parts were not locally available. - standard vs non standard pipe dimensions meant increased number of interconnects and increased price. The key reason for sticking with a 15/22/28 standard was that it was immediately available and did not require any specialist skills or tooling to install, along with a simple method to connect with existing installations or indtustry standard fittings. In terms of flow rates and restrictions, neither system (Pex-A or Hep2O) provide any significant restriction to flow as whilst Pex-A uses expanded pipe around a full bore fitting, the Hep2O sleeve is now stainless and does not impede water flow at all. There are also a whole host of issues around the actual design of the fittings and what happens if you apply lateral stress to them which are based on the material they are made from which makes them susceptible to low flex failure but that’s beyond this discussion I expect....
  45. 1 point
    "Crossovers" should be done in the ample joust space and then the services dropped in order so they don't have to cross again . Not so important with cables but deffo with pipes. You shoukdbt actually have that many pipes in the same single service void so a bit of planning goes a long way 👍
  46. 1 point
    There'll be a little test button on the RCD that'll say "Test Monthly" etc. You press it and it should trip every circuit upstream of the RCD. Just because it trips by pressing the button doesn't mean it's safe but it's a reasonable indicator. As the trip is an electro mechanical assembly (coil imbalance picked up by a search coil triggers a solenoid type deal) pressing the button ensures the mechanism is less likely to gum up over time from being static. Of course you will have to go round resetting all your clocks etc! Different from an RCD tester which is a special bit of kit that basically tests how fast the RCD works. Nice explanation and little diagram picked at random: https://www.electricalengineeringtoolbox.com/2016/01/how-residual-current-device-rcd-works.html?m=1
  47. 1 point
    This site seems to explain the regulations well and doesn't mention a minimum diameter for hand rails. It also says that the first 2 stairs do not need a handrail https://www.wonkeedonkeerichardburbidge.co.uk/building-regulations-explained/
  48. 1 point
    I thought I would put a post together for those that are looking for windows, replacement or new build. As someone who deals with final order placing / final quote discussions. One of the things that crosses my desk on regular basis, is that the "other supplier" is more cost effective. Which leads me to ask myself "more cost effective against what" are you comparing apples for apples? When I ask people to compare, what we generally explain is to look at the following (see below) if they are not willing to supply a copy of the quote without prices. Product - is the product similar. For example are you comparing a Timber Aluminium cladded window with a Timber Aluminium cladded window? Glazing - Is the glazing on offer from both suppliers comparable? Is it double glazed v's triple glazed for example or is it float glass v's toughened or laminate? Check that doors have toughened/laminated glazing Check that windows within 300mm of a door have toughened/laminated glazing Check that windows below 800mm from the finish floor have toughened/laminated glazing Check that windows that are 1400mm in height or above for toughened/laminated glazing. Most suppliers will start to consider toughened / laminated from 1400mm onwards, some will still be float glass. Check triple glazed glass units. Some suppliers will only toughen the inner and outer panes and leave the middle pane as float glass, others will toughen all 3 panes (I recommend all 3 panes as toughened) when required. Why? quick example is from experience, a customer in the north west of Scotland had the middle pane as float glass in french doors, the doors are recessed with wall on either side. It effectively became a wind tunnel. What happened is during high winds, the door sashes had that much wind pressure constantnly, that the door sash was pushed away from the frame slightly and a rattle effect occurred (only thing I could think would cause this to happen). As a result the middle pane (float glass) shattered. This required the whole sash to be replaced, as the glass was glued into the frame on that particular product. Timber - Is the timber comparable, are both using spruce/larch/oak/pine etc.? Are any of the products finger jointed as standard (which is more cost effective versus fixed timber, but not as aesphetically pleasing). Is the timber cut from from one section of wood or is it individually glue laminated timber? Ug values - A 0.5Ug can be quoted by suppliers but the costs vary dramatically. One of the reasons for this can be the glass make up and the gas that is being used. Some quotes won't tell the gas being used but it's safe to assume that if it's 48mm glazing it is Argon. Pay attention to the spacer distance also, not for cost but if the spacer is above 18mm, convection can occur of the gas filling (gas moves around in the unit). Hinging - Are the hinges concealed or are they exposed? Door Hinging - Pay close attention as suppliers will have quoted standard framing on doors, others may have increased the widths of the jambs to increase the space available at the hinging for plastering behind. RAL Colours externally - are the quoted RAL colours the same? Internal colours - have they quoted the same? Some will offer the standard colours such as a clear lacquer, others will have them painted - does this have any impact on price comparison. Sizes - have any of the units been split, due to not being able to achieve the size required? Some suppliers will not be able to do large sizes, others will be. Look out for compromises. Don't always look at the end figure and immediately reject a quote as being to high, compared to the others. Most suppliers will have the supply price first, then additional items such as window cills, compriband, membrane, installation etc. which are optional to the quote and not necessarily required but may be included in the total cost at the end. Most self builders like to take on the mantra of doing the whole build, others would like to leave this to the supplier or builder and or source their own materials if supply only. What is being offered with the installation service, are the installation options / costs comparible to each other? Who takes responsibility for the windows upon arrival? Generally speaking most suppliers who are installing, should be taken responsibility from the moment the windows leave the factory, to the moment the windows/doors have been installed, sign off. If supply only, the responsibilitygenerally passes to the client once the offload commences. So it is important to document the windows before offload, during offload and once offloaded. The manufacturer will normally have documentation / pictures before departing the factory, it makes life easier on whether a claim with the haulage company or whether a claim with the supplier is required (both should go to the supplier who should deal with it). Warranty - how long is the warranty, what does it cover? Last but not least, is the quote comparible? Have the suppliers referenced things the same way or are have the drawings been scaled and then referenced by the supplier (this happens a lot when no window schedule exists)? A lot of architects don't create window schedules for some reason (one the major parts of a build and most costly aspects) and problems of missing windows can be encountered, due to the elevations not always showing "hidden" windows which can be seen on floor plans. Some suppliers can miss this, which then impacts that quote. Hopefully some people find this useful, of not apologies for the long read
  49. 1 point
    This post is summary of the Principal Designer thread. The purpose of this summary is to assist members and guests decide for themselves how CDM2015 impacts their build project. The summary is offered as is and should not be interpreted as authoritative advice. As is normal in asynchronous online discussion, the thread sometimes changes its focus a little. Where those changes occur, the content has not been summarised. Discussion of this issue is particularly relevant to us because we are a self-build forum, whose members are assumed not to be professional builders, or -in relation to building- have any technical understanding or capability beyond simple DIY . To be clear, the following assumptions are made; · A client is a Domestic Client. The distinction is central to all that follows · The Domestic Client can choose to apply for VAT relief in due course, whereas a Client cannot · The Domestic Client is not engaged, or about to be engaged, in a business related to the build (because they will then be a Client, not a Domestic Client) The thread started with a question about the role of Principal Designer. The examination of that question inevitably lead to discussion about how the role related to other key aspects of the legislation. There was some reference to the history of Health and Safety legislation, but it was pointed out that over time, the general emphasis had not changed. If you qualify for Domestic Client status, then a contractor working for you carries the main responsibility for Health and Safety. It was in the detailed examination of the term ‘responsibility’ that a good deal of discussion arose. Several members agreed that the legislation was poorly drafted for our sector of the market. And in the context of a self-build forum, where many of us will be doing things for the build on our own (DIY) as well as employing contractors, it is easy to see a rich source of confusion. For example, self-builders might be tempted to become involved in the build in a way which implies technical competence and so enhanced H+S responsibility. A strong warning was given to self-builders to avoid becoming involved in technical aspects of the build to the extent that they might be considered ‘ a responsible person’. And that includes the self-builder being trained in a relevant build subject to the extent that he or she might be assumed by the courts to have more responsibility than a Domestic Client would be expected to have. Perhaps the simplest articulation of how CDM responsibilities can be operationalised was in this post (@jamiehamy) ‘… We have only used contractors for the steel frame, lifting in floor beams, ground works/drainage and electrics - and each time I've made it clear that the contractor is responsible for operating safely and I do not dictate how they complete the activities. I don't supervise on site and most certainly do not manage their work or how they work - they have a deliverable and it is their responsibility to complete that. Where required, I offer safety equipment, ask what they need me to provide to work safely and healthily, I find out if they are dependent on me for anything and let them get on with it. Maybe I should do more in writing but I choose reputable contractors and all work is fully invoiced…’ In terms of prosecution for H+S breaches, providing the Domestic Client has fulfilled their duties (not covered in detail in this summary) prosecution is highly unlikely. Domestic Clients should make sure the site is safe and secure, tidy and clear of obvious hazards. There was some discussion based on the meaning of a series of CDM-specific terms; Project Manager, PD, PC, Client, Domestic Client, Business or Business Activity, Contractor, design, designer as well as others. Please refer to the full discussion for a more detailed discussion. But it was convincingly argued (with supporting evidence, and some unevidenced dissention) that a Domestic Client cannot be either a Principal Contractor or Principal Designer. Additionally, there was some discussion of official legal documents related to CDM2015. In summary: be sure to understand the meaning of the term Domestic Client, and to maintain that status throughout the build. Any competent person with whom you have a contract to complete work on your site should be capable of working safely. Offer support to fulfill H+S requirements, but never offer advice or direct work or manage the process. If, after reading this summary you feel you need to, take care to seek advice from more than one reliable, authoritative source. Paying for advice does not guarantee its accuracy or authority. Source url forum.buildhub.org.uk/ipb/topic/2376-principal-designer-role/ Bibliography. HSE (2015), Managing health and safety in construction. Construction (Design and Management) Regulations 2015, HSE Books downloaded 04/05/2017 http://www.hse.gov.uk/pubns/priced/l153.pdf See especially Appendix 6. HSE (2015), How CDM 2015 applies to Domestic Clients Appendix 6, Figure 1, in Managing health and safety in construction. Construction (Design and Management) Regulations 2015. Download the flow chart (from our server) here HandSforDomesticClients.pdf HSE Construction Discussion Forum (accessed 04/05/2017)
  50. 1 point
    10mm Pipe For Hot Water Taps? (Content copied from EB) Started by Eagerbeaver , 24 Jan 2016 07:56 AM 10 replies to this topic Eagerbeaver Posted 24 January 2016 - 07:56 AM All the water pipe installs I've seen use 15mm pipe but the flow capacity of 15mm is far more than is needed for most hand basins and sinks. The down side of using 15mm for hot water is that you end up with a lot more cold water to shift in the pipe before it runs hot. Is there any problem with using 10mm for hand basins and sinks for the hot water? tonyshouse Posted 24 January 2016 - 09:13 AM For very long runs pressure drop could result in too slow flow, avoiding using elbows will help Would be fine with combi or pressurised system or three storey situation. Nickfromwales Posted 24 January 2016 - 10:21 AM What lengths are the runs? Also, are we talking about a radial plumbing setup ( critical if considering using 10mm runs ). 10mm is perfect for wash hand basins, but kitchen and utility would probably be better with 15mm for short, higher volume draw offs where 10mm may struggle. If there's not a good / very good cold mains pressure / flow rate at the incoming supply then excessively long runs may suffer, Regards, Nick ProDave Posted 24 January 2016 - 10:38 AM I'm considering this. In my new house, the kitchen will have the longest run, about 6 metres. I'm planning to try a 10mm pipe for the kitchen hot water tap to minimise the volume of cold that has to be drawn off before the hot arrives. We have good water pressure and food flow at the source so I think it's worth a try. jsharris Posted 24 January 2016 - 10:38 AM It's commonplace on the continent to see narrow pipe runs to basin taps, not sure if it's usually 10mm or 12mm but it looks a lot smaller than our normal pipe of 15mm. With a decent head 10mm pipe will flow a fair bit of water, more than is usually needed for wash basins or even sink taps, dishwashers etc. For guidance, a 10m long length of 10mm OD copper pipe causes a pressure drop of about 1.7 bar at a flow rate of 10 litres/minute. Sink taps rarely flow at more than 6 litres/minute, 10 litres /minute is about an average mains pressure shower flow rate. What this means is that if you have a head at the start of the pipe of at least 1.7 bar then you can get a flow rate of 10 litres/minute from the open end of a 10 metre length of 10mm OD copper pipe. We have an available head of around 4.5 bar, so I could have used 10mm pipe pretty much everywhere and still had good enough flow rates. The downsides with using small bore pipe is that you pretty much have to use a radial plumbing arrangement, with the pipe from each outlet fed back to a common manifold, you can't really run two or more outlets from a single pipe, as they will interfere with each other to a greater extent than with larger bore pipe with a lower flow resistance. Another downside is that if you try and flow 10 litres/minute through a 10mm OD pipe then it will make a noise, especially if you have a fairly high head of pressure at the manifold. The noise is acceptable at up to around 6 litres/minute, but any more and you need to increase the pipe diameter to quieten it down. For comparison, the pressure drop across 10m of 15mm OD copper pipe is a great deal lower, at around 0.2 bar for 10 litres/minute flow rate. Plastic pipe flow rates are lower, or the pressure drop higher for a given flow rate, because they usually have a smaller bore for the same OD as copper pipes. cjard Posted 24 January 2016 - 10:46 AM I looked a using a range of different pipe sizes but in the end just used 15 mm throughout for the following reasons I'm using plastic, and the bore is a little smaller than copper 15ml so there's a little less volume of wasted water A metre of 15mm plastic holds about 70ml more water than a metre of 10mm, given my longest pipe run from manifold to sink is 5 metres, that's less than a teacup. The longest shower run is 10m but, for the duration a shower runs, the excess is a drop in the ocean Plastic doesn't suck the heat out of the water the same The manifolds are 15mm, and I'd have to adapt down to 10. Plastic fittings at pretty bulky and ugly at the best of times and it adds cost and points of failure Flow capacity isn't the be all and end all. If you rush water through a pipe you can create areas of low pressure where it will boil temporarily and make a horrendous noise. A bigger pipe flows more slowly isn't as prone to this cavitation cjard Posted 24 January 2016 - 10:53 AM ProDave, on 24 January 2016 - 10:38 AM, said: I'm considering this. In my new house, the kitchen will have the longest run, about 6 metres. I'm planning to try a 10mm pipe for the kitchen hot water tap to minimise the volume of cold that has to be drawn off before the hot arrives. We have good water pressure and food flow at the source so I think it's worth a try. Consider an instantaneous heater that will use a little electricity to heat the initial water and then dial back on its output as he hotter water starts arriving. Saves water, maybe saves the planet if you have renewable electricity. Such instant heaters can be good for occasional use households as it beats having a large standing volume of hot water losing heat constantly jsharr Posted 24 January 2016 - 10:57 AM cjard, on 24 January 2016 - 10:46 AM, said: I looked a using a range of different pipe sizes but in the end just used 15 mm throughout for the following reasons I'm using plastic, and the bore is a little smaller than copper 15ml so there's a little less volume of wasted water A metre of 15mm plastic holds about 70ml more water than a metre of 10mm, given my longest pipe run from manifold to sink is 5 metres, that's less than a teacup. The longest shower run is 10m but, for the duration a shower runs, the excess is a drop in the ocean Plastic doesn't suck the heat out of the water the same The manifolds are 15mm, and I'd have to adapt down to 10. Plastic fittings at pretty bulky and ugly at the best of times and it adds cost and points of failure Flow capacity isn't the be all and end all. If you rush water through a pipe you can create areas of low pressure where it will boil temporarily and make a horrendous noise. A bigger pipe flows more slowly isn't as prone to this cavitation I did the same, used 15mm plastic everywhere, for much the same reasons. I did initially try running 10mm copper, but it was far too difficult for me to pull through posijoists on my own and I scrapped two lengths and then gave up and switched to 15mm plastic. Plastic is a hell of a lot cheaper and one roll did the whole house. I'd definitely NOT use 10mm plastic, as the bore is a lot smaller than 10mm copper, and restricted further by the inserts. Nickfromwales Posted 24 January 2016 - 01:10 PM I've ( on a previous job ) used 10mm Hepworth with the slimline stainless steel inserts and the flow rates were more than adequate. Longest run was prob about 13-14m. I used 10mm to each WC purposely to reduce water velocity and stop the WC from over monopolising on the available water pressure ( quite a significant short turn effect on showering when not reinforced with an accumulator ) which gave the desired results, and also reduced the noise of the cisterns filling too. The basin hot and colds were all in 10mm and performed well. Manifold 15mm outlet with a 15x10mm reducer. Hepworth 10mm direct to outlet with zero joints. 10mm exposed behind basin ( out of sight ) terminating into fitting reducers ( female each side ) and then a piece of 15mm copper made off to a male 15mm x 1/2" fitting which the tap connector fits into. Everything else in 15mm, for simplicity ( one size fits all ) more than anything Regards, Nick. ProDave Posted 24 January 2016 - 05:49 PM Sounds like in my case 10mm to the kitchen sink will be okay. It's the only pipe run in this direction and the longest run from the hw tank. All the rest (bathrooms and utility) are the opposite direction and will be more conventional. the bulk of the run will run parallel to one of the posi joists so I will try and run it in a coil of 10mm copper. VIPMan Posted 24 January 2016 - 06:20 PM I've used a 15mm manifold system with 10mm copper to basins. 15mm plastic to bath and shower. Maximum runs around 17metre. Still a work in progress but flows seem reasonable with around 4.5 bar mains pressure.
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