80 year old house with no insulation (Pacific North West), cedar lath barely holding stucco on but it has to come off. I intend to add 1″ foam insulation to the outsides of the studs then sheath for stucco. What thickness sheathing is standard for stucco?
This post, in response to your question, will bump the thread through the 'recent discussion' listing again which will increase it's viewing.
Perhaps it will catch someone's attention that can help you with advice.
Use EIFS. It is a commercial product and comes in various thicknesses. I believe common application is 2". You can go thinner.
You then apply a mesh into an adhesive mortar bed then a pre-colored finish coat.
It is the stuff you see on many commercial building exteriors.
When you're this good, EVERYONE wants a crack at you!
Here in the PNW EFIS has gotten such a bad rap that if you are a contractor and even looked sideways at the stuff you won't be able to pay for your insurance. And if you can get insurance it will have waivers of any problems associated with the EFIS.
Correctly done by knowledgable people it can be a great system, I am not knocking it, but the insurance companies have it on their "short" list.
Thanks for the information. I have been reading about EFIS and it looks like stucco on top of an insulation board is my best bet.
The "devil is in the Details" applies with any stucco over foam . Doesn't matter if it is true EFIS or not. Flashings, sealing and preventing water infiltration is the key .
I have never touched the stuff my self, having heard early reports of problems with bad installation ,water damage and mold, so I have no personal experience to lend.
I just know of the insurance problems from conversations with my agents and with a number of friends who are local contractors who got caught up the ensuing insurance mess.
There may be others here who do have experience with it and can guide you .
Like some others have mentioned here EIFS has a real bad reputation. This is partly because of the building code and partly because contractors cut corners.
The Kunstharzputz (In NA known as acrylic stucco) is used in Europe for decades and has no reported problems. However they have strict codes to prevent waterpenetrations into the outside walls. Fibreglass insulation is not the best insulation for this applications. We have used rigid 6" EPS (like the Nascor product) without any problems. In the Northwest the use of a rainscreen will also work.
You can build the outside wall like this: 2x.. studwall, insulation, 1/2" sheathing, 60 min tarpaper, 3/4" pressuretreated strapping, 1/2 sheathing, 1" foamboard, fibreglass mesh embedded in acrylic stucco, finish coat. An insect screen on the bottom will prevent insect infiltration. Some also leave a ventstrip on top of the wall strapping to get all the moisture out of the cavities
One of the problems we found when repairing EIFS walls: Aluminum windows with mitred corners where the caulking failed and the water in the rainchannel acutally drained into the exterior wall behind all the waterproofing. Poor flashing like capflashings without standing seams, just caulked with an 1" overlap, no flashing where roofs run into a wall, etc. Then the EIFS gets all the rap