Home  5  Books  5  GBEzine  5  News  5  HelpDesk  5  Register  5  GreenBuilding.co.uk
Not signed in (Sign In)

Categories



Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book.
Buy individually or both books together. Delivery is free!


powered by Surfing Waves




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.




Housing - Renovation: UFH/Towel Rail for First Floor Bathroom - Timber Suspended Floor. Controls?

Bottom of Page

1 to 30 of 59

  1. <
  2. 1
  3. 2
  4. >
  1.  
    My bathroom has a heatloss of 60w per m2, I intend to run the UFH at 45c flow during the coldest months so can get away with <300mm pipe spacing but will opt for ~100mm

    Can someone please describe the design for said system? How much insulation? mix and depth of biscuit mix? Will chipboard flooring instead of timber floorboards suffice?

    I intend to ply and then tile in exposed areas only which is ~2m2 tops

    I do intend to run a small towel radiator (above bath narrow edge) which I was thinking to to run on the return of the CH circuit (radiators) with no TRV fitted.

    How would I control the room temp?

    The only other room in the house that would have UFH would be the kitchen/diner

    Thanks in advance
  2.  
    Forgot to say the floor joists are 7 x 2" at 400mm centres spanning a 3.4m distance (over two rooms)

    The width of the room along the span is just 1.8m

    Will said joists suffice?
    • CommentAuthorCWatters
    • CommentTimeJun 26th 2014
     
    I would avoid putting too much on top of the UFH. Problem is you need a very rigid base for tiles but at the same time it wants to be thin to let the heat through. For that reason I would go for one decent layer of good quality WPB. Avoid two layers such a chipboard _and_ plywood. You may need to beef up the joists if the floor bends when walked on.
    • CommentAuthorCWatters
    • CommentTimeJun 26th 2014
     
    Heatmiser make a programable room stat with a wired remote sensor. Stat goes on the wall outside bathroom door. Wire through hole in wall to sensor inside bathroom. Keep it away from the towel rad.
  5.  
    Will the joists take the weight?

    Can someone confirm specs for insulation, thickness of screed?

    What thickness WPB would you reccommend? 25mm?
  6.  
    We just had a delivery of dry screed boards from Cellecta, they interlock like normal chipboard however have very little thermal resistance and will get the heat through room the UFH around 4x faster. This is for our floating floor system so not sure if it would work with yours but worth a look perhaps?

    They are more expensive but hoping that we will get much more out of our UFh this way, plus they are great for tiling.

    So maybe you could insulate between joists, use pipe trays with diffuser panels and then the dry screen coards directly onto joists?
  7.  
    Here is a pic from this mornings delivery. they just glue up like T&G chipboard.

    They are also acoustically rated for sound proofing.
  8.  
    price?
  9.  
    I think they were around £14-15 +VAT, but half length of normal boards. i.e 1200mm x600mm
  10.  
    Okay so not too expensive, although I can get WPB for free

    Can anyone advise on teh construction method for holding the insulation/screed and the thickness of the floor boards required?

    Not getting much 'technical' advice here?
  11.  
    Can someone please advise on the spec for said floor?
  12.  
    Please can someone advise? This is my next phase
  13.  
    Please please please can someone advise? I can't install the bathroom till the floor is done. I have everything sitting there at the moment.

    Basically I need to know:

    1. How do you support the insulation/screed with there being 400 centres?
    2. What size WSB to use? 25mm?
    3. Best method of controlling the temp....
  14.  
    I'm practically begging now.....

    Can I:

    1. attach 2x2 to the inside edge of the joists
    2. lay 50mm EPS on top, do I need thicker insulation here or does the EPS need to sit on ply or similar?
    3. 15mm pipes in a 25mm screed (dry biscuit mix)
    4. Then 25mm WSB on top of the joists? Or can I get away with thinner boards for better heat transfer?

    Can someone please, please, please offer advice as the bathroom is just sitting there empty....
  15.  
    daily bump
    • CommentAuthorCWatters
    • CommentTimeJul 2nd 2014 edited
     
    The problem is there isn't really an ideal set up for UFH a tiled floor on joists. There are contradictory requirements. The floor needs to be thick/stiff for tiles and thin for UFH to let the heat through. Perhaps why people are reluctant to offer advice.

    Should use >80mm of insulation if it will fit and PIR is better than EPS.

    Questions such as "will the joists take the weight" are for a structural engineer.
    • CommentAuthorCWatters
    • CommentTimeJul 2nd 2014 edited
     
    I think I would ..

    2*2
    18mm WPB
    80mm foil covered insulation
    UFH stapled to the insulation
    Biscuit mix

    As to what goes on top google tiling a wood floor an look for advice on new floors rather than overboarding and existing. Perhaps..

    http://www.netweber.co.uk/tile-fixing-products/help-and-advice/problem-solutions/tiling-onto-wood.html

    At least 18mm WPB and 21mm is better. Should be screwed down every 150mm.

    Essential to use a flexible tile adhesive (try BAL) and follow maker recommendation regarding any prep of the WBP.
  18.  
    Sounds great! Thanks for getting back to me

    I presume if I rest the UFH pipe in the insulation with biscuit mix so long as I only ever use no more than 25mm screws for bath legs etc there will be no issues
    • CommentAuthorCWatters
    • CommentTimeJul 3rd 2014 edited
     
    You can get clips/stand offs to fix the pipe to the insulation. May need them to get the pipe to lay flat.

    I wouldn't put pipe under the bath fixing points.

    How are you connecting the UFH to the existing heating? Single room mixer and loop pump?
    • CommentAuthorCWatters
    • CommentTimeJul 3rd 2014 edited
     
    If the bath is of the type that has to be sealed to the wall it's important to make everything as rigid as possible - otherwise the sealer never lasts long. Worth making up a proper box frame out of 2*4 or similar. At very least fix a batten to the wall to support the edge. The more rigid you can make it the better. We designed out the problem by opting for a free standing bath with wall mounted taps.
  21.  
    <blockquote><cite>Posted By: CWatters</cite>
    2*2
    18mm WPB
    80mm foil covered insulation
    UFH stapled to the insulation
    Biscuit mix
    </blockquote>

    Is there any need for the 18mm WPB? Would 100mm EPS100 sit nicely on top of the 2x2 and be sufficient to support the 25mm biscuit mix?
    • CommentAuthoralec
    • CommentTimeJul 7th 2014
     
    I used fir tiles on a timber floor..

    Insulation between joist, 8mm ply glued to polyplumb cement board (or similar) and large tiles glued to that...pipes in cement board...
  23.  
    Am I right in saying that the perimeter of the UFH will require an insulated upstand? What about in between each joist itself?

    Will it matter if the biscuit mix runs under the adjacent bedroom by 200mm or so or should I cut it short of the bathroom by 200mm instead? The end joist lands 200mm to end of shower tray.
    • CommentAuthorDave_07968
    • CommentTimeOct 10th 2014
     
    I'm no expert, but for what it's worth, I've got 25mm PIR internal wall insulation on my bathroom refit and I'm taking it down to the plasterboard ceiling of the room below. This will hopefully tackle issues of air infiltration in the subfloor and partially insulate the UFH biscuit mix from the outside walls at the same time. If there's enough offcut material I may double it up to 50mm in the subfloor void.

    Certainly you want to avoid coupling the heated screed to the external wall, or it will suck out a lot of heat.

    Where there's a choice I'm erring on the side of more area & more pipe rather than less - as I understand it the issue is struggling to extract enough heat from the UFH rather than struggling to get heat into it (if that makes sense), on which basis I would take it under the bedroom a little rather than missing an area out.
  25.  
    I've actually prepared it under like you said, and it's all heat in the envelope anyway.

    Can anyone suggest the best pipe layout to minimise notches? Or can I do as many 15mm holes as needed? I assume there is no need to clip these runs down as it will be a dry mix and the osb board on top will hold it tight. I was thinking of a serpentine pattern?
    • CommentAuthorCWatters
    • CommentTimeOct 10th 2014
     
    Joists should only be notched/drilled in specific places. Guide here to safe areas..

    http://www.eastdevon.gov.uk/bc-guidancenote7-notchingofjoists.pdf
  27.  
    Thanks, that will make it easier
  28.  
    Do I need ceramics in the bathroom or will vinyl floor work with the ufh? I imagine ceramics will be best to retain the heat

    Although I won't be tiling under the bath so there's only 1m2 of usable area.

    I have a few spare green chipboards, will this work instead of buying in wsb?
    • CommentAuthorCWatters
    • CommentTimeOct 12th 2014
     
    You can use vinyl but I think the UFH temperature must be limited?
  30.  
    I think I'll stick to ceramics, do I need to tile under the bath or is it okay to leave it ply wood as the finish?

1 to 30 of 59

  1. <
  2. 1
  3. 2
  4. >
   
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   
Logout    

© Green Building Press