Is this OK

Discussion in 'Builders' Talk' started by dvddvd, Mar 14, 2008.

  1. devil's advocate

    devil's advocate New Member

    J.T. Builders Ltd.

    Must be a hoot having you around the house doing a job.

    Such a rich appreciation of irony "and stop being a n*b"
     
  2. devil's advocate

    devil's advocate New Member

    Dvddvd.

    Looking at my last post (to you...), you'd need a separate membrane for the cistern itself to tape around the vent pipe.

    Ie: tape (using good gaffa-type-tape) a plastic sheet to the top outside edge of the cistern, making sure you also cover and seal any holes (handle holes, etc). Then seal this membrane to the vent pipe. Try not to leave any of the outside surface of the cistern exposed to the 'venting' air.

    Whether it's then best to add another membrane around the whole boxing, or to leave this free to breath - I dunno :( Needs thinking through...
     
  3. dvddvd

    dvddvd Well-Known Member

    Hi thanks again, the frame and cistern I was looking at has a insulated cistern fitted, but when/if I get it I will have a good look at it and work something out.
     
  4. Captain Leaky

    Captain Leaky New Member

    Plonkers United I see! :)
     
  5. GKU

    GKU New Member

    Stop wasting your breath guys - let him get on with it
     
  6. Water Systems

    Water Systems New Member

    What he wanting to do is remove some inner blocks and fit a concealed cistern where the blocks were. It would be under a window and not affect any structural aspects. That so?

    His concept is sound. If he removed the inner blocks he would need to seal up the cavity all around the opening, so that no water will drop down the cavity if a leak in the cistern. The cistern is the same depth as the blocks. On the inner side of the outer brick install Kingspan or Celotex high performing insulation to keep the insulation values up.

    The quality of the work must be high to maintain sealing all around the sealed cavity.

    What he is doing is no less than those awful inset electric meter cupboards which drag heat out of a house at amazing speed. They don't seal up the cavities or put insulation behind. They cool the cavity big time and create a chimney affect sucking cold air in and out the cavity.
     
  7. Water Systems

    Water Systems New Member

    If u were a builder of any kind u would know that u
    should never bridge the cavity with anything but wall
    ties or trays, period!

    What the hell is an insert electricity meter cupboard? What does that do?
     
  8. The Dormouse

    The Dormouse New Member

    It seems there can’t be much wrong with any innovation that is rejected by some tradesmen. Afflicted by the Not Invented Here syndrome they start by damning it as an idea of the DIY devil that no self-respecting professional would be seen dead with. Then after a decade or two of successful use by amateurs they reluctantly adopt it as though it was their idea in the first place.
     
  9. Water Systems

    Water Systems New Member

    Most tradesmen haven't an ounce of creative thinking in their whole bodies. They base most on what they have done for 25 years.
     
  10. ecm

    ecm New Member

    Most tradesmen haven't an ounce of creative thinking
    in their whole bodies. They base most on what they
    have done for 25 years.

    :O

    Serious question, is Devils Advocate a teacher?
     
  11. devil's advocate

    devil's advocate New Member

    SHUT UP AND SIT DOWN!
     
  12. HOTDOG ø

    HOTDOG ø Active Member

    In my (considerable)experience good tradesmen are both creative and ingenious on a regular basis. However there is a point where creativity becomes a lash up.

    This sorry story is a good example of muddled "lash-up" thinking.
     
  13. hallbeck

    hallbeck New Member

    I agree Hotdog - in particular general builders are very good at thinking their way round a problem. But you do have to be careful that you don't get too creative and end up with a bodge!
     
  14. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Hi dvddvd.

    The insulation problem I'd be most concerned about is
    condensation forming on the cistern wall.

    On an exposed cistern, the condensation droplets
    would normally evaporate away after the room returned
    to 'normal' humidity levels. Or else it drips to the
    floor and evaporates there :(

    In your situation, air won't be able to circulate to
    dry it off, but moist air probably will still
    be able to penetrate the casing/wall to condense on
    the cistern wall.

    So, I'd suggest the best solution would be to try and
    prevent the moist air getting to it in the
    e first place. Ie: fit a membrane (virtually any
    kind of plastic sheet) around the outside of whole
    boxing to seal it off from its surroundings, Pack
    between the boxing and the cistern with insulation -
    poly beads/ loft insulation, ?

    Even with this, you could have problems... Imagine
    what happens when you flush the loo - water empties
    from the cistern to be replaced by air. This air
    will be sucked in from outside the boxing.
    When the cistern fills, this air will be expelled
    d and end up around the outside of the cistern wall -
    inside your boxing. It'll condense, and the
    water will be trapped inside your
    waterproofing membrane :(

    So... I'd suggest a vent pipe added to the top of
    your cistern, venting to the cavity behind it. Bring
    your membrane sheet up around this pipe and tape it
    tightly around it - all the cistern air should
    hopefully be taken in and expelled only via this pipe.




    Sorry to disagree wit that DA, well not really :)


    But as I see it, the cistern being inside a box will be largely protected from the warmth of the room, so inside the box, the cold water will keep the inside of the box reasonably cool.

    Therefore, minimising condensation.

    Also(on the vent idea), it wouldn't surprise me if the cistern has an internal overflow(overflowing into the bowl) which will act as a vent, which would actually be better all round as a slightly warmer air would be entering the cistern from the warmth of the room(but only slightly). Anything making the water warmer would help prevent condensation.

    If though, it needs to overflow to the outside, an added problem of getting the pipe through the box, the insulation and the outer brickwork arises(regarding keeping everything insulated properly. Not a big problem, but needing consideration.


    Mr. Handyandy - really
     
  15. devil's advocate

    devil's advocate New Member

    Happy to disagree, Mr Ha - and I do

    "...the cold water will keep the inside of the box reasonably cool.

    Therefore, minimising condensation.
    "

    It's the fact of the cistern being cool that could cause condensation, when warm, moist air fro the bathroom permeates the wall and boxing.

    Also, "...slightly warmer air would be entering the cistern from the warmth of the room... would be precisely the type of air you wouldn't want, as this kind of air will be holding a greater amount of moisture in it.

    All ready to condense out when it hits the cold cistern...
     
  16. ecm

    ecm New Member

    SHUT UP AND SIT DOWN!


    Take that as a yes then. Sooooooooooooooooooo obvious.

     
  17. devil's advocate

    devil's advocate New Member

    I'll have you know I was a smug, patronising, know-all with a seriously up-my-own-**** attitude waaay before I became a teacher.


    Anyways, I ain't one any more...
     
  18. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Happy to disagree, Mr Ha - and I do

    "...the cold water will keep the inside of the box
    reasonably cool.

    Therefore, minimising condensation.
    "

    It's the fact of the cistern being cool that could
    cause condensation, when warm, moist air fro the
    bathroom permeates the wall and boxing.

    Also, "...slightly warmer air would be entering
    the cistern from the warmth of the room...
    would
    be precisely the type of air you wouldn't
    want, as this kind of air will be holding a greater
    amount of moisture in it.

    All ready to condense out when it hits the cold
    cistern...




    No, DA. The fact that the cistern is concealed in a box, means it is not in the room area, so not as subject to the room warmth as it would be if it were in the room.

    Therefore, inside the box will be cooler than inside the room. This is a bonus towards preventing condensation(less temperature difference=less condensation).

    On the subject of the air being drawn in through the overflow pipe, this enters the INSIDE of the cistern, and if the air entering the inside of the cistern is warmer, this would further lower the difference between temperatures inside and outside the cistern.

    It seems the project is actually giving more benefits than at first thought.


    Mr. Handyandy - really
     
  19. dvddvd

    dvddvd Well-Known Member

    The cisterns comes insulated so will that mean that it does not matter how cold the water thats entering the cistern with the insulated cistern it will not effect the outside of the cistern with condensation.
    On a normal built in cistern in a boxing these must be prone to condensation, thats why they must insulate the actual cisterns to combat the problem.
     
  20. Water Systems

    Water Systems New Member

    The cisterns comes insulated so will that mean that
    it does not matter how cold the water thats entering
    the cistern with the insulated cistern it will not
    effect the outside of the cistern with condensation.
    On a normal built in cistern in a boxing these must
    be prone to condensation, thats why they must
    insulate the actual cisterns to combat the problem.

    An insulated cistern is perfect.

    Have you considered putting the cistern in the loft with a long hidden flush pipe? The flush mechanism needs to be electric. The volume of water can be far less than using a low level cistern, saving water if on meter.
     

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