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How to approach a contractor?

marnichol | Posted in Energy Efficiency and Durability on

38′ by 39′ single storey with a walk out basement 20′ by 21′ garage. Living in PEI Canada(cold/very cold climate so says the maps)
I’m really wanting to build our new home with REMOTE wall ideas. One big problem is that my wife wants a very certain place to build and we have to go with that contractor. This contractor currently builds with 1″ of polyiso on the exterior and I understand that I need to increase that, I’m thinking 4″ xps, plus blown-in in the 2×6 stud cavitey. What are some ideas on how to approach the contractor with enough information ( but not too much) on why 1″ isn’t enough and that in cold climates more is better.
Any experience out there about cost, the savings of interior vapor barrier and house wrap(probably a few hundred vs couple thousand) vs Grace Bituthene, 2×4 vs 2×6.
On a side note is 4″ xps and 5.5″ of blown-in too close in ratio for the osb. Could you ever sell the idea in Canada of building 2×4 walls again??
Thanks in advance,
PS A million more questions after this, lol. (icf vs form foundation using exterior foam down to the footings) but we’ll talk about this later.

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  1. kenorakq | | #1

    Hi Marty. I'm building in Kenora, Ontaio so I feel your pain. Instead of XPS I think the majority opinion is to use EPS, its less expensive and performs BETTER as the temperature drops (thats NOT the case with XPS).. I have been asking a ton of questions and getting considerable guidance at If you haven't been there yet have a look...its a MUST read like this site is :)
    Regarding the AMOUNT of exterior foam...there are code rules and NO 1" does NOT make the grade). I got considerable push back from contractors too.... most said 1" only one would go to 2" inches and that's still insufficient. I think the problem is they haven't done it before and they a ren't interested enough to learn. Its the old ".... been doing it it this way for years..." mentality.
    Granted there are some issues getting long enough screws to go through furring, 4" EPS, OSB and then into the stud but that CAN BE DEALT WITH... its all been discussed at the a/m site..

  2. wjrobinson | | #2

    Would be so nice if you could get the right contractor who already was building super insulated homes. Are you sure there isn't someone willing to drive to your site or maybe guide whomever is the ultimate builder?

    A good contractor should be able to build from a good set of plans, can you get the plans drawn?

    I just wondered how cold you were right now way up there... it's actually colder here right now 24 degrees here. Would love to visit in July some year...

    There's a great crew of experts that are in Maine.... give them a call maybe? Chris and more...

    Have a look at your local architects

  3. marnichol | | #3

    Thanks for the quick answers, the temp right now at 11:30pm is 1C or about 33f. We definantly are not a cold cold place for extreme periods, lots of freeze then warming.
    The EPS will have to be considered since there is a major producer just a province over, TrueFoam in NS.
    The contractor owns the subdivision and has a contract with a local building supply company, Island politics. One needed the other for water to be allowed to build the subdivision so no changing that. I'll just have to get everything costed out and maybe have to do some of the grunt work myself.
    The real kicker is that the father of the contractor is building a Passive House right now, last I heard had .18 on their air change. Any ways thanks again for the info and the leads, onward marching.

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