Shearwall Plywood Over Lathing 1

[cslater]

Sometimes the questions we get from homeowners just make us scratch our heads and wonder what they were thinking...

Still - they need an answer.

We got a call today that someone installed their shearwall plywood over the top of their stucco lath paper/wire and they want to know if that's okay.

On the one hand, the plywood is still attached to the underlying studs, providing some lateral bracing. On the other hand, there's now a gap between the two.

Anyone have a suggestion on where to go with this?

Thanks!

 

[csd72]

Nails dont work very well in bending, the lathing needs to be removed and the plywood connected directly to the studs.

csd

 

[cslater]

So that's why they always bend when I'm driving them in!

Ideally they would remove the lathing and connect directly, but the question is whether there's any other solution that is less costly.

For example, more nails, or possibly using screws to suck the plywood in tighter to the studs.

Again - I know the answer is "that's not the best way to do it", but I'm just curious to know if anyone has seen a work-around or even a code provision that provides for a reduced allowable shear in this situation.

 

[Lion06]

If the sheathing on the inside of the wall isn't in place yet, maybe you can attach the plywood there.

 

[WAMRE]

The 2003 IBC Table 2306.4.1 provides shear values for plywood shearwall sheathing placed over the top of gypsum sheathing (most codes have a similar table). This is not your situation - and it appears that the gypsum sheathing can actually give you higher shear values when you combine the plywood and gypsum sheathing - which you do not have. You should contact APA to see if they have any information or suggestions.

 

[wikidcool]

Stucco has shear value all by itself, although not very much. I take it it won't pencil out without the plywood?

I agree you should hit up the APA - they might have a tech. bulletin about it or something close that would give you insight to the behavior of the system.