Walls and Roofs
The easiest way to insulate walls from the exterior in older homes
Fitting extra insulation to an older home when renovating can be a great idea, but when insulating exterior walls from the outside take care to do it right. Ec…
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Anytime you put insulation on either side of metal, like putting batts of insulation between metal studs on exterior walls you will have unnecessary heat loss. Read more here about how to reduce thermal bridging. There are cases, like yours I would say, where insulating between metal is really the only option due to size restraints.
In such a case if you need to do it anyway, I would say hemp insulation is a pretty good choice as it has a really good capacity to store moisture, and there is a greater risk of condensation when there is a metal passing from the interior to the exterior of an insulated space. You will be able to Buy Hemp insulation in Canada and the US here very soon, as an alternative I would propose rock wool / mineral wool insulation as it is also less likely to be harmed by any incidental exposure to moisture.