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Insulating downstairs ceiling

  • 05-03-2019 09:39PM
    #1
    porrige
    Registered Users, Registered Users 2 Posts: 38 ✭


    Hi,

    We have hollow concrete slab between floors (unsealed at the ends).
    Underneath are 50x50 battens with 50x50mm counterbattens attached.
    We have UFH upstairs with 50mm insulation & 50mm screed.
    Our stairwell opening is 800x3600mm.

    Is it worth insulating between ceiling & 12.5mm plasterboard slab ?

    Thank you.
    Tagged:


Comments

  • #2
    MicktheMan
    Registered Users, Registered Users 2 Posts: 2,952 ✭✭✭MicktheMan


    To what end?


  • #3
    Riar_
    Banned (with Prison Access) Posts: 12 ✭Riar_


    porrige wrote: »
    Hi,

    We have hollow concrete slab between floors (unsealed at the ends).
    Underneath are 50x50 battens with 50x50mm counterbattens attached.
    We have UFH upstairs with 50mm insulation & 50mm screed.
    Our stairwell opening is 800x3600mm.

    Is it worth insulating between ceiling & 12.5mm plasterboard slab ?

    Thank you.
    Sound or warmth?


  • #4
    porrige
    Registered Users, Registered Users 2 Posts: 38 ✭porrige


    Riar_ wrote: »
    Sound or warmth?

    Warmth & energy efficieny. Not concerned about sound.


  • #5
    BryanF
    Moderators, Home & Garden Moderators Posts: 10,147 Mod ✭✭✭✭BryanF


    Don’t bother, you’d be better to sort out the air-tightness and duct-runs/grill positions.


  • #6
    porrige
    Registered Users, Registered Users 2 Posts: 38 ✭porrige


    BryanF wrote: »
    Don’t bother, you’d be better to sort out the air-tightness and duct-runs/grill positions.


    And assuming the junctions are airtight, but air from wall cavity (150mm platinum ecobead) can penetrate the hollow cores ? ...I just don’t see the point of heating up 200mm hollow core slab with 50mm of insulation on top plus open ends.
    - but I’m no expert & perhaps I’m missing something ? - maybe danger of condensation within suspended ceiling void ?


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  • #7
    BryanF
    Moderators, Home & Garden Moderators Posts: 10,147 Mod ✭✭✭✭BryanF


    porrige wrote: »
    And assuming the junctions are airtight, but air from wall cavity (150mm platinum ecobead) can penetrate the hollow cores ? ...I just don’t see the point of heating up 200mm hollow core slab with 50mm of insulation on top plus open ends.
    - but I’m no expert & perhaps I’m missing something ? - maybe danger of condensation within suspended ceiling void ?

    I don’t see the point insulating an internal surface. Solve the air-tightness and thermal building envelope.


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