insulation question

[kgmunro]

can I insulate the outside of my shop and house over top of the existing stucco with foam sheeting? I am going to vinyl side the house and want to add some insulation first, but don't want to tear down the stucco if at all possible. I will be installing new windows as well.

 

[kbs2244]

Can you?
Yes.
Should you?
That is another question.
Stucco over what? Is it real, trowled on stucco, or panels of "look like" stucco?
If it is panels, take them off and work from what is under them.
If it is a frame building with metal lath and trowled on stucco you should cut through the stucco to the framework so you can nail on "sleepers" to level the wall for your siding.
If it is a block building with trowled on stucco, again you have to cut though it down to the block so you can nail on the sleepers.
The problem with stucco is that it is uneven. You need some way to get a flat surface for the siding to be nailed to.
You walls will be much thicker than normal also. So your new windows will need extra carpentery work to install.

 

[kgmunro]

it is a framed building with metal lathe and trowled on stucco.
the window manufacturer says no problem to the extra depth, as the windows can be framed accordingly. I was worried about mounting the siding and insulation to the stucco,but I guess you can use concrete nails (yes/no??) to mount the wood strips to the stucco.
Also...should the foam insulation be house wrapped, or is that only for the bare walls before anything is applied?

 

[kbs2244]

No, no, no.
You cannot trust the stucco for structural purposes.
It is just a coating.
Think of it as a thick coat of paint.
You have to fasten your sleepers to the framing behind the stucco.
If you don’t want to cut away the coating then you are going to have to find the real wood behind the stucco, shim your sleepers so that they present a flat surface for the siding, and then screw them through the stucco with screws long enough to penetrate the stucco and attach to the real building.

 

[myt4d]

Your Stucco issue is a tough one...here are some things to consider. How big are the overhangs on the home? Adding sleepers with long nails or screws over stucco and new foam insulation than a new vinyl is going to really shorten the overhangs. Not a big deal if they are say 24" overhangs. Here is a thought as well... you can use a new vinyl product with a foam type backing and achieve about an R2. Stucco is not going to hold up with the vinyl attached via a concrete nail. The siding has to be able to move as it expands and contracts and its fastener must remain stable to allow this movement. You are in for a lot of line snapping and stud searching if you decide to go over the stucco with the vinyl. Stucco is not an even surface but if you nail sleepers tight to the wall...neither will your sleepers be straight. the beauty of vinyl is that it is NOT nailed tight and therefore has a great deal of functionality on a...not so straight surface. The house wrap like Tyvek is a wind barrier product....you have plenty of wind barrier.
Find your studs and be sure you find them ...use a good 3" galvanized type roofing nail use a product similar to this and it will kill 2 birds at once.. http://www.alside.com/index.aspx?page=4
Be sure you do a good job caulking the holes you make while looking for studs. (vinyl condensates thus it has weep holes...you don't want that water in the stucco). Don't cover up rot....cut it out patch it primer it and than cover it up. Take some photos have fun and work safe.

 

[kgmunro]

thankyou very much guys I appreciate the help.