How can I insulated the outside walls of a workshop without doing harm?

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How can I insulated the outside walls of a workshop without doing harm?

Charley Nelson Aug. 27, 2021Last updated: Aug. 27, 2021

I have recently decided, due to the astronimical costs of hydro in Ontario, to further insulate my shop. My exisiting shop is 2x4 framed, with R14 roxul and 6 mil vapour under drywall. (No AC) The exterior is poor mans board and batten. (1/2" plywood with 1x2 battons at 16"oc.) This combination, with a 4000 watt fan heater, costs about an additional $150 to $200 in hydro per month if I heat it to 16 degress C for 6 to 8 hours a day and maintain 'frost free' at night.

If I remove the battons, add 2" of foil clad ISO and vinyl siding to add R13, should I be concerned about moisture? What else should I be considering, beside a more economical heat source?

Thanks you in advance for your help

Charley

Responses (3)

Charley Nelson
Charley Nelson Oct. 8, 2021, 12:25 p.m.

Thanknuou so much for the returned I formation. Unfortunately, I am bound by local municipality interpreters building codes and they would fail without the interior standard 6 miles vb. So it is there. The exterior, (framing out...) is 1/2" ply, 2" (r13) iso foam... double sided foul, and now vertical vinyl siding.

Where should I be looking for degradation over the years? Will it be the plywood in the middle? 

How can I mitigate the degradation?

Thanks again.

Mike Reynolds Oct. 8, 2021, 2:32 p.m.

We may be misunderstanding each other Charley. I was running with the assumption that you had a vapour barrier already. The solution of adding 5 + inches rather than only 2 inches shouldn't make a difference to building inspectors, but it helps protect the walls. If you go with Mineral wool though, it doesn't matter how much you add, moisture will go through anywhere from 1 inch and up, it's with foam that you are best to go a bit thicker. Does that make sense? As for what to look for with degradation, I would target a method that works well so that you have nothing to look for. Does that make sense?