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Best Wall System for Zone 4 Climate

Emel | Posted in General Questions on

We are in zone 4 and I’m currently trying to select the wall system we want to use in the hopes to avoid issues with mold. We are primarily heating however, for three months in the summer, we get between 80-95 and humid. It’s not tropical humidity, but too much to open windows.

We’ve considered SIPS but it sounds like those can have some issues. Also, if there ever was damage, it sounds like it would be hard to repair and also ease of moving of electrical or plumbing in walls if ever needed, ect…

We’ve also considered standard stick built, Rockwool insulation with a smart membrane over it like CertainTeed’s Membrain, or using Fiber Batting with a Kraft paper backing, then the drywall.

Moving outward, we’d have plywood or OSB (plywood if it’s in the budget), tyvek, and then a rainscreen prior to siding. If it’s in the budget, we would also like exterior insulation but my concern is making things so vapor impermeable that nothing can dry outward if moisture were to get trapped.

Thank you in advance for thoughts and tips. We are also considering a product we heard of that aerosolizes a compound prior to drywalling that seals every hole, but not sure if that’s needed. It’s called Aeroseal

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  1. walta100 | | #1

    There is no one best wall.

    Passive house proponents think the best wall is the wall that loses the least amount of heat regardless of the price to build it or how thick it is
    Production builders think the best wall is the least costly wall the inspectors will allow.
    I think the wall that costs the least to build and operate over the next 20 years is the best wall.
    Some might decide the wall most likely to survive a nuclear war is the best wall.

    All walls are very deferent and best in their own way.

    If you tell us what in important to you, we may be able to give you some advice.

    It seems to me the market place of ideas has come to the conclusion that SIPs are a poor value.

    There is nothing wrong with your standard wall except for its costs. Why Rockwool and not cellulose almost the same R value per inch much lower cost much less imbedded energy. Why buy a smart membrane in zone 4 seem total unnecessary as the wall paint is enough vapor control in zone 4. Fiberglass bats are so often poorly installed I tend to ignore it as an option.

    I think Aeroseal is a good idea but the pricing seems strange to me. They price X dollars to seal to 2ACH50 and much higher price if you want a lower number. Seems to me the pricing is set to allow sloppy builder to keep building the same leaky building and let the Aerseal make them code compliant for a known costs.

    My zone 4 wall is paint, drywall, damp sprayed cellulose insulation between 2x6 16 on center, Zip sheeting cover with one inch of XPS foam and then foam backed vinyl siding.


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