Home  5  Books  5  Magazines  5  News  5  GreenPro  5  HelpDesk  5  Your Cart  5  Register  5  Green Living Forum
Not signed in (Sign In)

Categories



Green Building magazine

Green Building magazine

New - Spring 2012 edition.

View the current issue.
Subscribe now.
Magazine homepage.
Browse back issues.





Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to new Forum Visitors
Join the forum now and benefit from discussions with thousands of other green building fans and discounts on Green Building Press publications: Apply now.




    • CommentAuthorCathyAshley
    • CommentTimeSep 23rd 2011 edited
     
    I want to install a basic shower by way of bath mixer tap. I don't want a proper shower - I've been quoted about £1000 for the electrical work and that is overkill on a ridiculous scale - so I realise it is a compromise (aka dribble) situation, but I want to buy a mixer set-up that works like a hand held shower but can also fix on the wall above us.

    I have got an immersion heater downstairs with a header tank in the loft. The cold runs off mains pressure. I haven't got any sort of pump and I don't know what the hot pressure is or how to measure it. I don't really want to replace any of the pipework if I can help it, I am very stingy and normally buy everthing secondhand and I would rather spend my time gardening than plumming. You can see I am a bath lover myself, but the kids would like a shower, and the WWOOFers, so I would welcome some advice about:

    1. The best type of mixer tap set-up to buy (and anything to watch out for);
    2. Whether it would make an appreciable difference to have a pump for the hot, and if so what sort of thing I am looking for, and
    3. Is there anything else I can do easily/cheaply to make it work better.

    Thanks for your help, kindly plummer-types.

    Cathy
    www.permaculturehouseintotnes.co.uk
    Followingthe evolution of a council house on its quest to become a farm
    • CommentAuthortony
    • CommentTimeSep 23rd 2011
     
    I would change the cold tap on the bath to a gravity feed from the same tank as feeds the hot. (cold pipe out of tank lower than hot)

    This will balance the pressures and allow you to use the cheapest mixer tap or even one of those that push fit on to the taps.

    There are some showers that will take mains cold and tank hot but they are pricey

    With mains cold and gravity hot you will never get a nice shower as the temperature will fluctuate too much for comfort and safety.

    Alternative is to store hot water at shower temp and only use the hot
    •  
      CommentAuthorJSHarris
    • CommentTimeSep 23rd 2011
     
    How much plumbing do you feel happy with doing yourself and can you gain easy access to the underside of your existing bath taps?

    If you can gain access to the underside of the taps easily enough, then swapping them over for a shower mixer should be pretty straightforward. If the taps are conventional, then just find a mixer tap that will fit the existing hole centres on the bath (they are usually standard, but worth checking). A look around your local DIY store should give you an idea of what's available at a reasonable price. Thermostatic shower mixers are more expensive, but help to control shower temperature more easily, whereas non-thermostatic mixers can be fiddly to set the temperature.

    You will need a tap wrench, a special spanner that fits up under the end of the bath to release the nuts that hold the taps in place and the pipe unions under there too. You'll also need new sealing fibre washers for the tap unions, usually they are 22mm pipe fittings.

    Turn off the water (including releasing the pressure on the hot system, by opening the taps after turning off) making sure that the boiler and immersion are turned off. With the system drained you can remove the old taps by undoing the pipe unions and pulling the pipes free, making sure not to damage them, just move them to one side (it will be a bit of a faff!).

    Next, undo the nuts that physically fasten the taps to the bath. These are usually under the pipe unions. With these removed the taps will come free. Clean up the bath where the taps fit and fit the new mixer tap. Secure the tap with the nuts, then remove the old fibre washers from the pipe unions (if they are still stuck to them, which they normally will be), clean up the sealing faces, fit new fibre washers and refit the pipe unions, making sure that they fit squarely and that the nuts don't get cross threaded (it's fiddly, as you're often working in a restricted area under the end of the bath underside). Tighten the pipe unions securely, but not overly tight - just enough to get a good seal. Turn the water back on, open the taps and let the air bleed out. When water flows cleanly, close the taps and, with a torch, carefully check the underside of the taps for leaks around the pipework. Leave the bath panel off for an hour or two, then double check that the tap unions aren't leaking. If all is well refit the bath panel.

    The shower head will need it's bracket fixing to the wall, which will mean drilling through tiles in all probability. Use masking tape to cover the tiles where you need to drill (it helps stop the drill slipping around), use a percussion drill and masonry drill bit to carefully drill through the tiles and into the wall for about 40mm. Before drilling check for hidden pipes and cables with a pipe/cable detector unless you are in no doubt whatsoever that there is nothing in the area. With the shower head bracket holes drilled, fit plastic wall plugs and screw the bracket into place.

    That's pretty much all there is to it, but it can be a bit of a fiddly job because of the limited space you have to work in.
  1.  
    what Tony and JSHarris said

    You can calculate the hot pressure quite easily, 10m height will give you 1 bar pressure, so if your shower head is 1.5m below the water surface of the header tank then you will have 0.15bar pressure at the shower head. If the bath tap is 1.5m lower than the shower head then the tap will have 0.3bar pressure (1.5m + 1.5m). If you could raise the header tank in the loft by 1,5m then you would double the shower pressure (in this example), but if you did this you would need to construct an insulated box around the stand and tank to ensure its inclusion in the house heated envelope to prevent freezing. The available pressure could be important depending on the type of thermostatic mixer tap you may choose. Check the manufactures details for any pressure restrictions.
    Peter
    •  
      CommentAuthorSteamyTea
    • CommentTimeSep 24th 2011 edited
     
    Posted By: tonyWith mains cold and gravity hot you will never get a nice shower as the temperature will fluctuate too much for comfort and safety.


    If you have a simple (cheap) mixer then you cannot use mains pressure (cold) and gravity fed (hot) together. What happens is that you pump cold back through the hot pipe to the cylinder and up to the header tank. This can become very dangerous.

    You will have to fit a new cold feed from the header tank to the bath tap.
    This means you will have to blank off the existing mains pressure cold feed near the bath taps.
    Plastic pipe (that blue stuff) is alright for this, as are the correct pushfit couplings (I bought 20m of the stuff as it was cheaper than getting the correct length cut, I still have 15m left going begging).

    Shall just reiterate, do not combine mains and gravity pressure.

    Oddly enough, if you fit electrical gear under the bath and behind a fixed panel, then it is considered outside a wet zone (cant remember the Zone numbers) and may be also be 'minor work' and not covered by the scope of Part P, so depending on the installation may be done by a competent person. I fitted my pumped shower this way (though it is RCDed and Fused correctly as well.
    •  
      CommentAuthorJSHarris
    • CommentTimeSep 24th 2011 edited
     
    Good point about combining mains and gravity fed. All the houses I've owned have had gravity fed cold water to the bathroom, so I'd forgotten about this.

    I believe you can fit some modern mixers to a mains cold water, gravity hot water system though, as most now incorporate a non-return valve to prevent the higher pressure cold feed being able to back flow up the hot feed. I fitted a new shower unit a year ago and it came with a restrictor washer that could be fitted to the cold water side to reduce pressure if used with a mains cold feed and the blurb also says it has non-return valves to prevent cross feeding. I've no direct experience of this system though as I now have mains pressure hot and cold, after fitting a combi boiler.
    •  
      CommentAuthorSteamyTea
    • CommentTimeSep 24th 2011 edited
     
    Yes you can get pressure reducers (not the same as flow reducers) and NRV, the trouble is that they reduce the flow to a tiny trickle (a typical British shower). Saves a lot of water, but leaves a lot of soap under the arms. If you like a powerful shower try one on a channel ferry, they can pin you to a wall :bigsmile:
    I put in a shower to 'save water' (6 quid a tonne here now, but no need to tell you that John). My lodger, who likes her showers can spend 40 minutes, at 11 litre a minute, under it. Think that is the real reason to fit the switch gear outside the bathroom :wink:
    •  
      CommentAuthorJSHarris
    • CommentTimeSep 24th 2011
     
    Your right, the washers are flow restrictors, they only reduce pressure downstream at high flow rates. Looking at the specs for the shower unit and taps I bought last year, it seems they all have built in NRVs. It looks like they have designed the NRV part into the tap itself, so no extra parts are needed (in essence, they seem to have made the valve float up and down on its shaft, so that it can act as a one way valve as well as a flow control). Even the kitchen mixer I fitted at the same time mentions that it has a built in NRV, so I'm wondering if they may now be a standard requirement.
    • CommentAuthorTimSmall
    • CommentTimeSep 24th 2011 edited
     
    You can get a reasonable fits-on-the-wall type of thermostatic shower mixer for about £120 or so, and install this above the bath - if you do this, go for one of the types which have separate controls for flow and temperature (others just have one control, and are either "off" or "on full blast" - you only then get to change the temperature.

    Spending another £20 to £30 over a no-name thermo-mixer can get you a named brand with a 5 year guarantee - so this may be worth considering.

    Unfortunately, the fits-on-the-bath-where-your-current-taps-are type (as opposed to the normal on-the-wall sort) of bath+shower thermo mixers are a bit more of a niche product, and often seem to be twice the price...

    Whether you can get away with a £30-or-so manual mixer tap or not depends on your plumbing - or rather you probably can, but it may well be that the extra plumbing necessary to ensure that when someone turns on the cold tap downstairs, whoever is in the shower doesn't get scolded may not make it worthwhile - i.e. no or minimal shared pipework between the shower and other stuff...

    Easy to see if this'll be the case with your current plumbing layout - if turning on a tap elsewhere or flushing a loo etc. makes the flow out of the bath taps reduce appreciably then you'd need to be changing around some of the plumbing or just going for a thermostatic type.

    In either case, the "aerating" type of shower heads seem like they may be worth a try - from about £25. The Mira and Ecocamel seem to be the main ones. Reviews here:

    http://www.daisygreenmagazine.co.uk/reviews/the-eco-camel-shower-head/

    Tim.
    • CommentAuthorCWatters
    • CommentTimeSep 25th 2011
     
    There are some shower mixers designed for unballanced supplies that use the cold pressure to boost the hot flow rate. I've no experience with them but they are typically called "venturi" mixers. Take care as for some makes that's just a brand name.

    http://www.tubz.co.uk/venturi_shower.htm

    I know Ideal Standard make one called the Trevi Boost..

    http://www.ideal-standard.co.uk/trevi-boost/venturi-shower-shower-e9105aa.aspx

    Also..

    http://www.newteamshowers.com/projects/cnew001/web/pid.nsf/webpages/ProductsVenturiJetStreamFeatures.htm

    http://www.heatweb.com/products/venturi/h2o.htm

    You might still need a pressure reducer on the cold. Trevi recommend a max cold pressure of 3 bar.
  2.  
    Thanks. I'm reading through and digesting all this...
  3.  
    I think a venturi type shower is where I will start. Thanks for those links CWatters, and to all of you for being genuinely helpful (I am scared of forums).

    What do you think of this?

    http://www.ebay.co.uk/itm/Trevi-Boost-Venturi-Mixer-Shower-built-in-chrome-plated-had-very-little-use-/280739641757?pt=UK_Home_Garden_Bathroom_Shower_Units_PP&hash=item415d62f99d

    How much extra on top of this would I have to buy? The actual shower pipes and head, is that all? Otherwise I'll follow up all those links and see what they cost new.

    There isn't much room in behind the bath so I will get a quote from my plumber for fitting it (apologies for mis-spelling 'plumber' and 'plumbing' before: I don't know what I was thinking!). I will compare this with the cost of changing the cold tap on the bath to a gravity feed from the header tank, but I think this is a more sophisticated solution. Otherwise it's going to be a coil of black pipe on the shed roof to a shower head in the garden!

    Cathy
    •  
      CommentAuthorJSHarris
    • CommentTimeSep 25th 2011
     
    Good plan to get a quote from a plumber for fitting it, as if you've not worked under a bath before you will probably find it a frustrating and awkward job to do!

    That shower mixer looks to be just the job, but you will need some pipe, fittings etc to couple it up to the pipework under the bath, a suitable shower head, hose and rail or fixings, a shower outlet connector that goes on the wall (if you want a flexible shower hose arrangement) and you'll also need to think about the work needed to make good afterwards. That's a flush fit shower unit, which needs to be recessed into the wall, with the pipe work also recessed into the wall. This will mean a fair bit of disruption, as the tiles will have to come off at the end of the bath, the wall will need to be channelled out and the whole lot re-tiled afterwards.

    I had a quote for tiling about a year ago and it came to around £40 per square metre for labour, plus the cost of the tiles. That didn't include making good the wall first.
  4.  
    I'll give the plumber a ring in the morning and see what he thinks about fitting it - whether he can come up with the pipework side of it. The dog bit him last time he came, so I hope he doesn't make a surcharge!

    If I end up getting a shower separately I think I'll get one of those Camel eco ones Tim mentioned above. It sounds pretty good. I just need all the gaps in between to go smoothly. I don't mind doing the tiling afterwards. My ex did the tiling and it's a very poor job that needs renewing anyway. Plus I don't like looking at his tiling while i'm soaking in the bath...
    • CommentAuthorCWatters
    • CommentTimeSep 25th 2011
     
    Google suggests the Trevi boost might be a bit fussy about pipe diameters. Perhaps try and get the fitting instructions before you buy in case you have to re plumb the run from tank to bathroom.
    • CommentAuthorRobinB
    • CommentTimeSep 25th 2011
     
    Cathy are you sure you're cold bath tap is mains fed rather than via the tank in the loft?
    In England quite commonly only the kitchen tap is direct from the mains.

    If you don't have the problem of unequal pressure from hot and cold I'd suggest buying a £10 push fit rubber hose shower and if feeling fancy a £7 bracket for the wall. This would at least allow you to check there is enough pressure to have a decent shower. I have lived in a flat where lifting the shower head more than 2 ft above the bath reduded the flow to trickle.
  5.  
    I've emailed the seller to ask if he would scan and send the instructions.
    • CommentAuthorCWatters
    • CommentTimeSep 26th 2011
     
    Found them here..
    http://www.fastpart-spares.co.uk/downloads/Treviboost.pdf

    Looks like the important points are...

    "The supply pipework should be 15mm copper on the cold side and 22mm copper on the hot side. A more stable showering temperature will be achieved if the hot supply pipe is taken from a direct cylinder connection."

    "The Trevi Boost is supplied with its own shower kit. (Handspray with flexible hose or fixed head). These are sized for optimum performance and should not be replaced with alternatives. If an alternative shower kit of higher or lower resistance is used the performance of Trevi Boost will be affected and a satisfactory mixed showering temperature may not be achieved "

    Does make it sound a bit fussy.
  6.  
    Thanks for this. I've just been talking to my plumber who didn't think they were still made. He put in a few (not Trevi) for customers in the past and they were all dissatisfied with the result. But now he knows they are made by Trevi (who he rates as good quality) he is going to get them to fax him the details and give me a quote. He thinks it might be a problem with the built in one - he says they are designed to be built in to the wall of a shower cubicle not the exterior wall of the house. He thinks I might be better with an external one so I think I won't buy the eBay one - especially if I need the full kit. If they are supplied with them, maybe the £250 trade price includes everything which would be better.

    Anyway, thank you all very much for your input. It was exactly what I needed.

    Cathy
Add your comments

    Username Password
  • Format comments as
 
   
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   
Logout    

© Green Building Press