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Loft insulation between rafters and tiles... is that normal?

Discussion in 'Floors, Stairs and Lofts' started by mattyjim123, 5 May 2021.

  1. mattyjim123

    mattyjim123

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    My first post on the forums after lurking for a while.

    I've just moved into a new house and peeked my head in the loft to find the insulation setup is different to what I've seen before. As well as just 100mm between the joists (that I'll be adding more to soon), there's a line of insulation at the bottom of the rafters, sandwiched between the rafters and the tiles.

    It has this on both sides of the roof, so seems pretty intentional.
    Here's a crappy diagram and a picture to help.

    Anybody else seen this before?


    [​IMG]
    [​IMG]
     
  2. Why Not Indeed

    Why Not Indeed

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    It might be intentional, but it's a bad idea as it's likely to be restricting airflow, preventing moisture from being carried away. On the other hand, if you're not seeing any damp then maybe there's not a problem. If you pull some away from the timbers in the corer, what state are they in?
     
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  4. Notch7

    Notch7

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    thats wrong

    insulation is at ceiling level and it should stop at the wall cavity

    its a cold roof design and must have through ventilation
     
  5. mattyjim123

    mattyjim123

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    Thanks for the replies. There's no condensation in the loft, but then again there are some pretty loose sections in the membrane where I can see the tiles above, so maybe there's some ventilation happening there.
    I pulled back some of the insulation at the edges and there isn't any damp or mould there either.

    I actually did some more digging on this, and found that it was likely done this way to prevent a cold bridge, where there's a gap between the wall insulation and loft insulation. So the idea is that the loft insulation should be tucked down the corner to meet the cavity wall insulation. There should be a channel for air circulation, but not sure I could see this in my loft.

    [​IMG]
    Source: Prevention of cold bridges (eden.gov.uk)

    I need to get into the soffits to run some data cabling, so will be removing it and replacing it according to the diagram above.
     
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  7. garyo

    garyo

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