Unattached Sheathing
Doing a bathroom remodel in Columbus Ohio, climate zone 5A. Tore down to the studs and discovered that a prior remodel had made swiss cheese out of the framing. So removed the cut up studs because they were no longer functional (due to being cut up). I put in new studs and checked to make sure the top plate was not bowed. But it occurred to me that the exterior sheathing was no longer attached in about a 36″ wide swath. The outside is stucco over wire mesh, nailed to the sheathing and studs. While the previous remodel (1960s) had already done most of the damage, there were probably a few functional attachments left which I cut through when removing the remnants. Of course, I could cut out places in the stucco behind the studs and reattach the sheathing/screening, but I’m not sure I wouldn’t do more damage. So far, no cracks in the stucco. I wondered whether I should put construction adhesive (yuck) on the sheathing behind the studs (2) then reattach the studs. Or just squirt some in. Or just leave it alone. We are contemplating a much larger project down the road to tear off all the stucco, put on exterior insulation (ZIP sheathing or similar), then reclad with something else. But, that project isn’t started yet, and anything could happen in the meantime. Any suggestions?
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Replies
I like to angle a deck screw into the side of the stud and into the sheathing. If you're fussy you can use a pocket hole jig to make a perfect hole.
An interesting idea. Screwing through the stud into the sheathing, right? Does this pull the sheathing towards the stud? How far into the sheathing are you trying to go with the screw? Are you aiming to catch the back of the stucco with the screw? This is fiberboard sheathing (e.g. Celotex) Do you find that it holds sufficiently? How far apart do you do this? 12" ? And do you do it from both sides of the stud, sort of like reverse toe nailing?
Does it ever make sense to drill through the stucco to the stud and use truss head screws to attach from the outside?
I didn't realize it wasn't wood sheathing. I've never worked with Celotex so I don't know.
In answer to your other questions, the goal is to pull the sheathing tight to the stud, you'd do it from both sides if possible and you want it to go into the sheathing but not through into the exterior finish.
When you have cut up studs, you generally sister the new ones. This avoids the issue you have but that ship has sailed.
Fiberboard is not easy to fasten to, I would put some construction adhesive in there for now and fix it properly when you replace the stucco.
Old stucco tends to be missing WRB and flashing details. This means insulating the studs comes with risk, something to be aware of as you might have to replace the batts down the road if this is the case for you.
What do you think of drilling through the stucco to the studs and using truss head screws to tighten that connection? I could put in the construction adhesive first then pop 3 or 4 screws along the studs every 24" to pull it to the adhesive. Or every 12", which is the manufacturer spec for fiberboard sheathing. Even if it didn't pull the wall in, the shaft of the screw would be supporting the stucco in some fashion.
I considered using anchors into the fiberboard from inside the stud bay attached to L brackets along the studs to hold the anchors to the stud, but wondered if the fiberboard had enough holding power through the anchor, or whether it would just pull through the fiberboard if we attempted to tighten it. And that would be only supporting the fiberboard, not the lath or stucco
When I first moved in, I discovered there was no wall insulation. I paid USA Insulation to pump foam in from the outside. That was a waste. As we then proceeded with remodeling different rooms, we discovered the foam had cracked and turns to dust at the slightest provocation. But found no moisture or rot anywhere. It's a ranch with 24" overhangs. Probably a fair amount of drying through the celotex/metal lath. We will be doing cut+cobble + batt on the inside which will be a significant reduction on air flow and vapor, so it's possible that we could develop problems, but I'm generally assuming the metal lath is likely to permit som drying outward for the celotex.
For future readers who might find this... I spoke with a stucco contractor who I've worked with before. He said since the stucco had not cracked or bowed, and the sheathing was still lying flat against the studs, to not do anything. The strength of the stucco might last 10, 20, 30 or even 100 years. Just fix it when it does show visible signs. They would cut out all the stucco and lath to the studs and put in new tar paper, lath and re- stucco just that bay. From his perspective, it's a small and simple repair, but not worth doing (for the homeowner) until the wall actually shows some signs of failure.