Soon I will be removing a lot of the wood lap siding on our 1938 house
and replacing it with fiber cement lap siding. The wood siding is in
poor condition and we are adding a room on the back of the house which
would make it impossible to weave in the fiber cement with the old wood
siding. Anyhow, I'd like to add insulation to the walls from the
outside while I have the siding removed. Currently the walls are not
insulated. I live in northern California and the walls are standard 2 x
4 studs, no plywood sheathing between the studs and the siding. I was
planning on using R-13 batt insulation but don't know which type-
unfaced, kraft paper or encapsulated in plastic. My preference would be
in order- encapsulated, kraft paper and then unfaced. I plan on
covering the insulation with either house wrap or 15 lb. roofing paper.
Is there any reason not to use the plastic encapsulated insulation,
stapled to the outside of the framing studs and then cover it with
either Tyvek or building paper and then the Hardiplank lap siding? The
interior walls are lath and plaster. Thanks.

Dale