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Insulate and Airtightness on a budget

  • 09-10-2012 7:47pm
    #1
    Villain
    Registered Users, Registered Users 2 Posts: 15,956 ✭✭✭✭


    Ok so my self build is finally moving again but on a reduced and pretty tight budget. I've given up and a HRV system and instead gone for a more affordable positive input ventilation system. The house was beyond wall plate by 2008 so current reg's aren't applicable.

    I have a 100mm cavity which will be pumped to give .29 cavity, it's a Dormer and I have a cold roof slated with modern vapor permeable felt with 7 x 2 rafters I had planned to put 150mm Metac between rafters but I'm not certain that is a good idea and I think 130mm with 20mm space between insulation and felt might be better?

    I'm looking for opinions on the above and also some guides on how to tape windows to get good airtightness. I have 9x2 joists between the two floorsI also have a suspended timber floor downstairs with 5x2 joists. I have a budget of about €4500 to insulate the house, €1400 is best quote for pumping the walls so that leaves €3100 to insulation roof, boot floors and between studs upstairs.

    Any ideas suggestions are appreciated.


Comments

  • #2
    BryanF
    Moderators, Home & Garden Moderators Posts: 10,146 Mod ✭✭✭✭BryanF


    Villain wrote: »
    Ok so my self build is finally moving again but on a reduced and pretty tight budget. I've given up and a HRV system and instead gone for a more affordable positive input ventilation system. The house was beyond wall plate by 2008 so current reg's aren't applicable.

    I have a 100mm cavity which will be pumped to give .29 cavity, it's a Dormer and I have a cold roof slated with modern vapor permeable felt with 7 x 2 rafters I had planned to put 150mm Metac between rafters but I'm not certain that is a good idea and I think 130mm with 20mm space between insulation and felt might be better?
    check fine print on the certification of the breather felt
    I'm looking for opinions on the above and also some guides on how to tape windows to get good airtightness.
    if your budget is that tight go and do course on it, you find them regualrly provide by one of the larger tape companies (S-Sounds like 'Liga' )
    I have 9x2 joists between the two floors I also have a suspended timber floor downstairs with 5x2 joists. I have a budget of about €4500 to insulate the house, €1400 is best quote for pumping the walls so that leaves €3100 to insulation roof, boot floors and between studs upstairs.

    Any ideas suggestions are appreciated.
    are the joists on hangers? are you plastering the wall entirely - i would, especially between the joists. are you installing a membrane in the floor and sealing it to the walls, and also a membrane below the roof joists with same taped and sealed to wall.

    these are details that many trades are still not familiar with, you need to either learn the skills or get someone site to advise you and your builders.


  • #3
    Villain
    Registered Users, Registered Users 2 Posts: 15,956 ✭✭✭✭Villain


    Cheers do you have any idea of where I can find info on the courses you mentioned?


  • #4
    BryanF
    Moderators, Home & Garden Moderators Posts: 10,146 Mod ✭✭✭✭BryanF


    start by typing 'airtightness training course'!!!

    see here also http://www.boards.ie/vbulletin/showthread.php?p=65050678 i found this on GOGGLE!!! ;)


  • #5
    Villain
    Registered Users, Registered Users 2 Posts: 15,956 ✭✭✭✭Villain


    Cheers had tried google but siga rather than liga helps :)


  • #6
    BryanF
    Moderators, Home & Garden Moderators Posts: 10,146 Mod ✭✭✭✭BryanF


    Villain wrote: »
    siga rather than liga helps :)
    S-Sounds like 'Liga' - what more can i do:rolleyes:


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  • #7
    muffler
    Registered Users, Registered Users 2 Posts: 46,550 ✭✭✭✭muffler


    BryanF wrote: »
    S-Sounds like 'Liga' - what more can i do:rolleyes:
    Its been a while but is Liga not what is fed to babies :eek:

    No problems with mentioning the Siga brand as its one of the "elite" brands for want of a better word. :)


  • #8
    manufan16
    Registered Users, Registered Users 2 Posts: 251 ✭✭manufan16


    I sent you a pm about the course, I done it and it was well worth it even if your not doing the air tightness yourself at least you will know how it should be done should you get a contractor in.

    With regards other ideas for cheaply insulating there are not many!
    EPS is a bit cheaper to buy than PIR ( although lower u value) I used a combination on my floor, one layer eps, the other PIR.

    Ask suppliers for cheaper alternatives to main brand leaders products but insist on spec sheet so you are know you are not compromising on the end u value you want to achieve.

    If drylining you can also get eps backed plasterboard rather the PIR backed plasterboard again a little cheaper but not alot.

    You could buy all the insulation and airtightness products and fit everything yourself if you have time but I assume you will be buying and paying 23% vat where if you get a contractor in supplying and fitting your paying 13% vat then is the difference between the 2 worth your time? It wasn't in every case for me.

    You should also keep an eye on the likes of done deal for bargains , seconds , excess left over from other peoples builds.

    Good luck.


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