A 40′ foot section of the front of my home is clad with brick and cedar shingles that supposedly date from the 1950’s. The rest of the exterior is stucco. I need to remove the brick and shingles and am considering stucco to match the rest of the house. Is there any reason why I should not sheath the exterior in OSB before I apply the felt and wire? I ask not only because of my very limited experience with stucco, but because all of the other stucco walls I’ve seen simply run the felt and wire directly over the 2×4 framing. I have plenty of extra OSB in the garage, and as the time and home are my own, I don’t mind overbuilding (if sheathing in this case qualifies as overbuilding). Thanks in advance for any advice you have to offer.
Steve
Replies
Steve,
Even though I have never done stucco, I would definitely vote for sheathing over those studs. I believe that everything I have seen that illustrated the layers in a stucco wall, always had sheathing underneath. Plywood, but I can't imagine osb would be a problem...
O.K. the second half of this email:
I am looking for info on stucco installation.
Need a source for the edging metal also.
Can you point me?
Patwig
I live in Southern California and OSB is used all the time under the stucco. As a matter of fact, every single tract home, 10's of thousands, use OSB. I haven't seen plywood sheathing on a house in a long time.
27Sean,
Thanks for the verification. I think I must have been lucky (or unlucky?) to have only worked on older homes in SoCal that did not have sheathing beneath the stucco. I'll be sure to sheath my own home remodel,
Steve
My own house is like that, built in the mid 60's.
No sheathing, just wire, felt and stucco. No insulation either.
At least we will never have a mold problem :)
This house breaths!!!!
there is no way new homes could pass code without any sheathing, at least if they are stick built with 2x4.
My house, built in 1957, breathes as well - a little too well. :)
Watch houses being built in California and the southwest. Code still allows the same techniques by which you house was built
Patwig,
Thanks for the response. It has been many years since I've shopped for anything stucco, and the supply house that used to have the metal edging is no longer in business. Once I look for it and find it, I'll let you know where it is.
Steve
I believe the stucco system on your house is a mortar type and I don't think would not do well over OSB. However systems, like Dyvit, are intended to be installed over OSB (If installed correctly) Years ago I worked on a crew that occasionally installed a stucco call Palladium. First a fiberglass type mesh was installed right on the OSB then a couple coats of product was applied directly on that. One dilemma with these systems, if you're looking to do the work yourself, is you need to be an approved installer to purchase and install.
Scott,
Thanks for the heads up. I am looking to do the work myself, so it looks like more research and thought is in order. Thanks.
Steve
Steve-
I used to do customer service on So. Calif. tract homes, and I serviced thousands. Most of these homes have 3/8" structural plywood shear panel at the corners, and sometimes whole walls. The stucco usually only cracks out from corners of windows and doors, and eventually around waist height all the way around. But if the stucco had the least bit of problems, it would crack over the shear panel in about 4' grid pattern. I only saw this happen over the plywood, not where it was paper over studs. The howmowner would be furious, but there was nothing we could do. We would color coat over it, and it would crack right through it. I believe it had something to do with how tethe plywood expanded with humidity, and I assume OSB would do the same thing. There is no need for sheathing if your studs are 16" o.c., and your stucco is 7/8" thick (believe me, I've torn out enough to know how strong it is).
Thank you for the advice. I'm finally doing the work this week - paper and lathe on the studs, no OSB. Thanks again.
Steve