Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie

What top up insulation would you recommend

Options
  • 15-01-2022 5:10pm
    #1
    BarraOG
    Registered Users Posts: 351 ✭✭


    With 100mm metac (0.034) between the joists, what would you place on top of it?

    If I put 100mm on top again I would have 0.175W/m2K. If I put 150mm on top instead that would give me 0.143W/m2K. Or if I were to use 200mm Rockwool (0.044), I would have 0.141W/m2K.

    Its will be difficult to put more on top in the future since you cant walk on it, so I'd like to future proof it as much as possible. There are a lot of beams and tank support structures and the likes in my attic so it wont be just a matter of throwing the stuff down. I will have to do a good bit of cutting. Is 200mm Rockwool awkward to cut compared to fibreglass?

    Pipes have insulation around them but are nailed to the joists. Does the insulation go on top? Can I leave the cladding on even if it will create more of a gap between the two layers? What should be done with the wires? Do they need to go into conduit? Do they have to go on top? I presume I don't need to do anything with the bathroom fan exhaust pipe.

    Thanks for your advice!



Comments

  • Options
    #2
    MicktheMan
    Registered Users Posts: 2,825 ✭✭✭MicktheMan


    In the greater scheme of things the quality of the work is more important that the quantity of insulation (100mm properly installed is superior to 300mm poorly installed). So go with whatever is easier to do properly. Ensure no gaps between insulation layers.

    Electrical cables on top of insulation, NOT in or under

    Bathroom fan exhaust duct should be insulated all the way to the exit point



Advertisement