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External insulation installers (Dublin) that will do more than the stock 100mm

  • 22-02-2023 9:51pm
    Registered Users Posts: 58 ✭✭


    As I've educated myself more, I see most installers have settled on the stock 100mm external insulation retrofit job. Various locations such as the PassiveHouse magazine, are stating that it is worth going thicker for long-term gains. I'd like to go to 200mm (or possibly even more if viable!). I have one company who are checking if they can go thicker but their initial view is a maximum of 150mm.....

    I'm struggling to find any installer in Dublin however - and my search skills are failing me in searching Boards if this topic has come up already.... Can anyone recommend companies?

    Thanks in advance.


  • Registered Users Posts: 33,871 ✭✭✭✭listermint

    Thicker will always be better.


    Passivehaus standards will be vastly different to normal home standards because you see trying to achieve an extremely regulated minimum spec and every aspect of the house construction is calculated to a mm cfm uvalue and so on and on.

    You most likely do not need 200 whatsoever at all for a retro. Your efforts should be concentrated on getting a decent EWI job done. Emphasis on air tightness around the dwelling and the efficiency of the heat generation and controls.

    Adding another 50 or 100mm is pointless if the dwelling has poor air tightness or a poor heat generation and management.

    150mm is more than enough for most applications but I'd spend the money more holistically. This is where heat surveys done by a professional with good guidance are more valuable.

    I caveat this in that I installed 200mm. But did so solely because I was doing it myself so spent the money on product than labour to someone else.

    It wasn't needed in any other area than my own brain :)

  • Registered Users Posts: 58 ✭✭usual_suspect

    Thanks for the detailed reply. Lucky you have the time/skill to do it yourself :)

    That's great to know about the 150mm guidance. Thankfully, I've gotten far enough in the research to recognise the importance of air tightness, etc. so that's also being factored into the plans.

    I'm very interested to find some more companies now who will go past the stock 100mm now - a choice of one isn't ideal :)

  • Registered Users Posts: 2,389 ✭✭✭1874

    I was thinking of doing EWI myself, Im interested to hear someone has already pursued and completed this. I want to do it as part of an overall plan of improving heat loss alongside airtightness,which is a much more difficult task as a retrofit imo. Did you get someone to do the external render or was it something you did yourself? Did you use a synthetic render or a more traditional material? We're you able to get any financial grant assistance? I am considering to see if I can get Nsai sign off/cert/approval as an installer and see if I can get grant approval? Although I think its less likely,it may even be cheaper to do without a grant. I have seen some quite poor work and I have not been encouraged by an Ewi work I have seen in progress, attention to detail,specifically no gaps that are "filled" with material that doesn't have the same thermal performance. Did you do below the damp course and ground level?