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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.

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    •  
      CommentAuthordjh
    • CommentTimeNov 24th 2019 edited
     
    Posted By: deniancethinking about getting a roll chopped up to fill in the tunnels

    It's probably easier to use batts rather than rolls, but it's perfectly possible to saw a roll to a smaller width before unwrapping it, so no problem either way.
    • CommentAuthorphiledge
    • CommentTimeNov 24th 2019
     
    Dont forget that the stuff youve already put in has probably bulged up to you'll likely have a "tunnel" under the insulation as well as between the insulation over the tops of the ceiling joists.
    • CommentAuthortony
    • CommentTimeNov 24th 2019
     
    Is that polythene on top of the insulation?
    •  
      CommentAuthordjh
    • CommentTimeNov 24th 2019
     
    Posted By: tonyIs that polythene on top of the insulation?

    Isn't the polyethylene what we've been discussing for the past thirty messages?
    • CommentAuthortony
    • CommentTimeNov 25th 2019
     
    I might have said this before but you must not have poly on the cold side of the insulation
    • CommentAuthordeniance
    • CommentTimeNov 25th 2019
     
    That’s how it comes , it’s part of the product, this is the first layer , there will be another 200mm over this, it’s supposed to be perforated but I don’t think it is!

    What happens if you have poly on the top?
    There’s poly on the bottom, it’s like a sock over the insulatiom
    • CommentAuthorLF
    • CommentTimeNov 25th 2019
     
    Looks like you have made a lot of improvement made, reminds me I have some more work to do on mine.

    As long as no water or humid air was in there it should be OK.
    If moisture is coming up from below and getting into the "sleeping bag" then it may condense on the top layer when it is cold. Say a tear near a wet air stream from a shower room below ?

    The sleeping bag insulation should be more resistant to wind blowing through the loft ? i.e. better when windy ?
    • CommentAuthorandyman99
    • CommentTimeNov 25th 2019 edited
     
    I don't understand why your space blankets have puffed up. Are they sealed at the ends? I have inherited some of these, they are tubes with open ends. If you push them into a slightly narrower width, they still squish down. Also I did wonder which way up they should go, so have now learnt something. Fairly sure mine are a random mix of orange up and orange down.
    On another note, I think the last time you posted, and certainly this time, was after the weather turned colder following a long spell of relatively mild damp weather. In my experience you can get short term problems in cold roof spaces until the drier air helps clear the damp. Just my observations of course!
    • CommentAuthordeniance
    • CommentTimeNov 26th 2019
     
    <blockquote><cite>Posted By: andyman99</cite>I don't understand why your space blankets have puffed up. Are they sealed at the ends? I have inherited some of these, they are tubes with open ends. If you push them into a slightly narrower width, they still squish down. Also I did wonder which way up they should go, so have now learnt something. Fairly sure mine are a random mix of orange up and orange down.
    On another note, I think the last time you posted, and certainly this time, was after the weather turned colder following a long spell of relatively mild damp weather. In my experience you can get short term problems in cold roof spaces until the drier air helps clear the damp. Just my observations of course!</blockquote>

    They puffed up with air in the bag, and they are slightly wider than the gap they sit in, when the other layer goes on they flatten down a bit, I’ve got a few more bays to do before I can put 2nd layer down, I’ll post some pics when I do it!
    But.... the cat joined me in the attic yesterday and he was fixated on the other side, got a feeling there’s bats there, what do I do about bats?
    • CommentAuthordeniance
    • CommentTimeNov 26th 2019
     
    <blockquote><cite>Posted By: LF</cite>Looks like you have made a lot of improvement made, reminds me I have some more work to do on mine.

    As long as no water or humid air was in there it should be OK.
    If moisture is coming up from below and getting into the "sleeping bag" then it may condense on the top layer when it is cold. Say a tear near a wet air stream from a shower room below ?

    The sleeping bag insulation should be more resistant to wind blowing through the loft ? i.e. better when windy ?</blockquote>

    <blockquote><cite>Posted By: LF</cite>Looks like you have made a lot of improvement made, reminds me I have some more work to do on mine.

    As long as no water or humid air was in there it should be OK.
    If moisture is coming up from below and getting into the "sleeping bag" then it may condense on the top layer when it is cold. Say a tear near a wet air stream from a shower room below ?

    The sleeping bag insulation should be more resistant to wind blowing through the loft ? i.e. better when windy ?</blockquote>

    Im sealing cable penetrations as I go, I had 3 spotlights there before which were letting air through, they’ve gone now and I’ve added lots of lap vents, I can see all the cobwebs blowing about so hopefully it’s vented enough
  1.  
    Posted By: denianceBut.... the cat joined me in the attic yesterday and he was fixated on the other side, got a feeling there’s bats there, what do I do about bats?

    Keep quiet - say nothing !!:sad:
    • CommentAuthortony
    • CommentTimeNov 26th 2019
     
    Probably only mice
    • CommentAuthordeniance
    • CommentTimeDec 1st 2019
     
    Did a bit more today!!
    Managed to get all my edges done!
    You can see in the picture that all the left hand side is now dark spot free on the ceiling!
    This is with heating off.
    I’ve also temporarily laid the 2nd quilt over the first layer, left half of picture, the second layer doesn’t seem to have done anything? Even though it’s now twice as thick! I’ll try it with the heating on I guess, plus I need to insulate the timbers between the first layer where it’s puffed up!
    I was hoping to see the timbers disappear from the thermal picture!
      275F0D2E-B06E-4117-A21C-E02511CDEA76.jpeg
    • CommentAuthordeniance
    • CommentTimeDec 1st 2019
     
    This is from inside the attic, guess I’ll have to up my game and fill in the tunnels under that 2nd layer!
      08C16DDD-D0DC-4FFE-A9E2-DD4F520ACE4D.jpeg
    • CommentAuthorphiledge
    • CommentTimeDec 1st 2019
     
    You can probably see the timbers because the humps in the first layer of insulation are lifting the second layer and youve got cold tunnels running over and along each ceiling joist. Probable solutions are above, but you could insulate a small area properly(without tunnels) and see if that warmed the ceiling joists so they dissappeared.
    • CommentAuthortony
    • CommentTimeDec 1st 2019
     
    A good example of thermal bridging through the joists. Need to add insulation to the shape of the “tunnel” on top of each joist before the second layer.

    From the point of view of the room below the joists are still seeing the thermal bridge, it should go once the tops of them aren’t loosing so much heat any more.
    • CommentAuthordeniance
    • CommentTimeDec 1st 2019
     
    Where the roof slopes into the edge ive tucked the first layer in, so it’s about an inch over the wall plate, easy peas, but the 2nd quilt is puffed up to 200mm so when I push this into the slope it’s not getting tucked right over the first layer, just due to the triangle shape of the roof against the 200mm square edge of the quilt!

    So with this in mind and the tunnels I’ve made I’m thinking buy a sacrificial roll of insulation and manually build up the triangle shape and also cut big Slices of this roll and fill in the tunnels

    The timbers are only 65mm deep and my first layer is 100 or 150 mm so this gives me the silly tunnels, wish I knew this years ago! Could of bought some 65mm first layer then! This may take a while!!
  2.  
    If you slit the poly bag open, you can peel off roughly half the thickness of wool to leave it 65mm deep between the joists. Then lay the bit you just peeled off, over the top of the joists and the wool between them, without gaps between each run.

    Loving your thermal pics, really good work!
    • CommentAuthorphiledge
    • CommentTimeDec 2nd 2019
     
    Buy a couple of rolls of 75mm insulation and cut it accurately to fit snugly between the ceiling joists. 75mm insulation will go further over the wall/wall plate without getting as squashed as the 200mm bags. You can put a second layer of 75mm in the eaves where its too tight for 200mm. Cut the plastic off the "bags" youve already got and lay the 200m insulation at 90 degrees to the first layer of 75mm

    In my very limited experience of the bagged insulation they just dont sit close enough to each other or any insulation above or below them so you end up with tunnels and thermal "leaks"
    • CommentAuthordeniance
    • CommentTimeDec 4th 2019
     
    Ok!! Update!!
    Was continuing in attic and noticed the new insulation was damp! Again!so I pulled it from the eave and noticed two cables dropping into plastic capping going to a socket!
    So I rigged up a diy blower door with a big desk fan and some plywood and depressurised the bedroom!
    Warmed up the socket with a hairdryer and watched through the thermal camera!! Air blowing out of the socket!!
    So this gotta be why it’s damp above it! Or just coincidence?
    I’ve filled holes up and I’ll check later with the fan to see if it’s worked!
    •  
      CommentAuthordjh
    • CommentTimeDec 4th 2019
     
    Posted By: denianceSo this gotta be why it’s damp above it! Or just coincidence?
    I’ve filled holes up and I’ll check later with the fan to see if it’s worked!

    Could be the cause; then again maybe there's some other reason, but as you say you'll be able to tell later. :bigsmile:
    • CommentAuthortony
    • CommentTimeDec 4th 2019
     
    Air leakage from the house into the loft will transfer moisture from the house to the loft as the partial vapour pressure of water vapour in the air in the house will be higher than it is in the loft if the loft is cooler than the house. When the loft is cold this moisture will condense.

    Now the horror story; 😱 even with no air movement this process will still take place, moisture will effectively be literally pumped from the bedroom into the loft. Think of it like a siphon, moisture from the air in the bedroom being sucked through the air (without the air moving) and condensing on anything cold. Through cracks, light fittings pipe boxing’s and even electrical conduits if they are not sealed.

    In Canada this happens in t/f walls when there is even a pinhole in the vapour barrier and icebergs form in the wall sometimes causing bulges in the cladding or breaking of plasterboard internal linings.

    😱
  3.  
    But on the plus side, there's probably 20+ million lofts in this country and most of them have very few icebergs indeed.

    Very impressed with deniance's approach to this, blower doors and IR camera combined with methodical approach and much persistence, I'm feeling inspired!
    • CommentAuthordeniance
    • CommentTimeDec 4th 2019
     
    <blockquote><cite>Posted By: djh</cite><blockquote><cite>Posted By: deniance</cite>So this gotta be why it’s damp above it! Or just coincidence?
    I’ve filled holes up and I’ll check later with the fan to see if it’s worked!</blockquote>
    Could be the cause; then again maybe there's some other reason, but as you say you'll be able to tell later.<img src="/newforum/extensions/Vanillacons/smilies/standard/bigsmile.gif" alt=":bigsmile:" title=":bigsmile:"></img></blockquote>

    <blockquote><cite>Posted By: djh</cite><blockquote><cite>Posted By: deniance</cite>So this gotta be why it’s damp above it! Or just coincidence?
    I’ve filled holes up and I’ll check later with the fan to see if it’s worked!</blockquote>
    Could be the cause; then again maybe there's some other reason, but as you say you'll be able to tell later.<img src="/newforum/extensions/Vanillacons/smilies/standard/bigsmile.gif" alt=":bigsmile:" title=":bigsmile:"></img></blockquote>

    God I hope so!! Doing my head in now!!, I checked the bays left and right and they were dry, the one with cables in was slightly moist!

    Scary thing is that when I had the fan on it was sucking an absolutely huge draught through the floorboards, it was cold air too! As if it was from outside! Deffo need to find that too, can’t be doing any good for my gas bills!!
    • CommentAuthortony
    • CommentTimeDec 4th 2019
     
    First floor void https://readinguk.org/draughtbusters/going-further/first-floor-void/

    There is also info on dormer bungalows, lofts and roofs

    I love what you are doing, well done with it all..
    • CommentAuthordeniance
    • CommentTimeDec 4th 2019
     
    <blockquote><cite>Posted By: tony</cite>First floor void<a href="https://readinguk.org/draughtbusters/going-further/first-floor-void/" rel="nofollow">https://readinguk.org/draughtbusters/going-further/first-floor-void/</a>

    There is also info on dormer bungalows, lofts and roofs

    I love what you are doing, well done with it all..</blockquote>

    That looks hard work!!! Is that the same for solid stone walls about 600mm thick?
    • CommentAuthordeniance
    • CommentTimeDec 4th 2019
     
    Won’t be needing this air leaky socket anymore!
      7C4E84A2-7FA1-44D7-82F0-45A4A4146562.jpeg
    • CommentAuthordeniance
    • CommentTimeDec 4th 2019
     
    Got the fan going again! The more I look the more I find!!
      A72487C9-3E00-408D-8F42-9E4E35CC148C.jpeg
    • CommentAuthordeniance
    • CommentTimeDec 4th 2019
     
    Air was flying through these!!
      48E44071-C27E-4928-856E-DEAF34B28603.jpeg
    • CommentAuthortony
    • CommentTimeDec 4th 2019 edited
     
    Solid stone walls may or may not be air leaky, where are the cold draughts coming from if not through the walls?

    Your leaky socket looks to me more like an air vent?
   
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