Trying to catch up …
Kevin Brennan| Posted inGeneral Questionson
I have a 1980, 2×4, tract home that I am remodeling in Zone 5. I’ve read a lot on walls and insulation, but I still don’t know what’s the good, better, best configuration to build. I am a novice and a community college student studying the trades, so I don’t know how to evaluate many of the potential combinations and I don’t want to create a problem layering incompatible products that will prevent the wall from drying out. I haven’t had success meeting anyone or finding organizations that care or believe these issues matter. I’ve made a ton of mistakes already, and I’m trying to minimize them going forward.
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To bring it up to current code-min performance you'd either have to add R5 continuous insulation (and completely fill the stud cavities) and would probably need to retroactively air seal the walls to some reasonable level. With R5 of continuous insulation on the exterior side of the sheathing it will keep the sheathing warm enough in a US zone 5 climate to not need an interior side vapor barrier- latex paint on wallboard would be sufficiently vapor tight. This would be one of the better/best ways to upgrade it, but it's not cost effective unless you are already planning on replacing the exterior siding.
See:
//m.etiketa4.com/blogs/dept/musings/2012-code-encourages-risky-wall-strategies
//m.etiketa4.com/articles/dept/musings/how-design-wall
With a semi-permeable interior and sufficient exterior-R for dew point control at the sheathing the assembly can readily dry toward the interior, and is fairly resilient to all moisture issues.
If your goal is to make the house Net Zero Energy ready it's going to need even higher performance, which can be had in a number of ways.
Kevin,
You forgot to ask a question.
I assume that you want advice on improving the energy performance of your exterior walls. The first thing you have to tell us (if you expect us to give you advice) is whether you are working from the interior or the exterior.
If you are installing new siding, you are working from the exterior.
If you have demolished the drywall or plaster, you are working from the interior.