Stucco to Stone Interface

[brianmiller]

Is stucco allowed to contact stone?

[Mark Reinmiller]

Is stucco allowed to contact stone?

Assuming there is a continuous weather-resistive barrier and basecoat behind the stucco and manufactured stone this is not a problem. Although the stone sill should slope for drainage. Caulking the joints between the stucco and stone would not be a bad idea either.

[brianmiller]

Assuming there is a continuous weather-resistive barrier and basecoat behind the stucco and manufactured stone this is not a problem. Although the stone sill should slope for drainage. Caulking the joints between the stucco and stone would not be a bad idea either.

Thanks, Mark...I would had thought some clearance would had been required but I never see any clearances. I'd also think there should be clearances from the concrete flatwork or above roof covering.

Another question: A couple of contractors have started to use metal flashing above the top horizontal stucco casement trim for windows. Most around here don't. Is it a requirement for the metal flashing? The picture I uploaded is without a metal flashing, typical around here.

[Darrel Hood]

In your photos of the stucco to flatwork and stucco to roof covering, I see no escape route for moisture behind the stucco. That can cause pretty serious damage.

[Mark Reinmiller]

Thanks, Mark...I would had thought some clearance would had been required but I never see any clearances. I'd also think there should be clearances from the concrete flatwork or above roof covering.

Another question: A couple of contractors have started to use metal flashing above the top horizontal stucco casement trim for windows. Most around here don't. Is it a requirement for the metal flashing? The picture I uploaded is without a metal flashing, typical around here.

Stucco should terminate two inches above concrete flatwork and two inches above a roof. There should be head flashing above windows. There was an exception in the BOCA, CABO, or early IRC (I forget which one(s)) that head flashing was not required for "self-flashing" windows. That is not the actual wording, but the code referred to integral flanges of a certain width. I believe all windows now require head flashing. Flashing would not be required above the stucco trim bands, but the top edge should be sloped.

Regarding stucco, except for installation performed in the past several years just about everything I see that is typical is also wrong. Much of it had been wrong for years.

[stanley frost]

The windows require isolation joints. Manufactured stone is considered to be the same as the top coat of three coat stucco (same rules apply) no sealant needed. Where the conduit penetrates the clading isolation joint needed. Around here that's one of the major problems that is contributing to moisture intrusion into the building envelope.

[DavidSmith]

Do you have specs showing where the isolation criteria are needed?

Thanks,

David


The windows require isolation joints. Manufactured stone is considered to be the same as the top coat of three coat stucco (same rules apply) no sealant needed. Where the conduit penetrates the clading isolation joint needed. Around here that's one of the major problems that is contributing to moisture intrusion into the building envelope.