This only increases the wall thickness 3 4 inch vs the furring strips william costello was planning to use and would only require increasing the interior window.
Fiber cement siding over 1 inch insulation.
When applying james hardie siding directly over the combined thickness of foam sheathing continuous insulation and other non nailable substrates e g.
Gypsum sheathing up to 1 inch thick the foam sheathing and other non nailable substrates do not have nail holding capacity.
With insulation thicker than 1 inch i would consider using wood furring strips on galvanized steel zee girts or hatbars so that you have enough options for proper fastening.
Of 3 to 3 5 which limits insulation thicknesses to 1 5 max 3 5 fastener to siding 1 embedment 3 5 0 5 1 5 1 5 max insulation therefore for insulation greater than 1 5 direct attachment of cladding though the insulation back to the structure is often not practical.
Measure the walls from top to bottom with a tape measure and buy either 4 by 8 foot or 4 by 9 foot sheets of rigid foam insulation to cover from the roof line of the house to the sill plate at.
Insulation is everyone having as much hell as i am installing fiber cement siding over 1 2 foam.
Installing hardie over 1 quot.
It then pops the nail right through the siding.
I seam to be blowing out the back side of the siding.
I have tried several different air setings for my compressor.
I would also consult a local structural engineer to make sure there is not undue force on the fasteners due to gravity load or wind load.
Siding over rigid foam a vented drainable air space keeps wood siding dry and stable.
We put 2 x 4 furring studs laid flat over the foam and attached to the wall studs with 1 5 inch foam between the furring studs rain screen over everything and finally the lp siding.
Fiber cement offers minimal energy savings at 15 r value but can be installed with fanfold or insulating sheathing products to improve the r value of the whole siding system.
One new wrinkle for many builders is walls built with fiber insulation.
Becouse the foam compresses.
You didn t indicate where you live but you could use a layer of tyveck paper to allow moisture thru from the inside to the outside and then cover this with lapped 15 asphalt felt to create a seperate drainade plane for any water comming from the rain getting thru the cement siding 1 inch rigid insulation could be applied beneath the siding and over the felt.