Exterior Paint Perm Rating
jackofalltrades777
| Posted in General Questions on
On exterior house paint on stucco. One manufacturer list their acrylic elastomeric hybrid paint as 25 PERMS and the other lists it at 8 PERMS. To avoid any trapped moisture behind the paint. I assume it would be better to go with the higher PERM rating paint?
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Replies
That's an interesting question, and I'll be following the discussion to learn more. For drying to the outside a higher perm makes sense, but as stucco is a reservoir cladding there may be some sense in limiting the amount of moisture it can take in from the exterior.
Behr's Elastomeric has the 25 PERMS rating and the Renew Elastomeric (by StuccoFlex) has the 8 PERMS rating.
See attached specs for each product (StuccoFlex on left and Behr on right):
I am also interested in thoughts but put my vote at higher perms. You will inevitably get moisture in stucco (cracks, humidity, etc) and allowing for drying while dissuading bulk water seems best approach to me.