Thanks for excellent information nicely presented. Just spent an hour browsing your site.
Iím more of a cabinet guy, but I rebuilt the 10í x 10í laundry wing on my small single-story SoCal home. Itís a wannabe craftsman kit home with redwood clapboard built in 1917, and received stucco in í47. Good materials, decently applied, 5/8Ē average thickness overall. No signs of cracks or degradation from moisture.
I cut the old stucco with an ablative blade on a circular saw. One cut, nice & clean. Now Iím ready to apply paper and pre-furred woven wire lath. How do I optimize the join between new stucco and old?
Thereís a vertical cut nice & smooth, showing base coast with embedded wire, and top coat. The cut slices the tarpaper beneath, and just scores the outer skirt of the clapboard. Then my new sheathing. Maybe I could work heavy wire into the horizontal gaps between each clapboard, even epoxy them in, and tie them to the new lath? Maybe I should chamfer the edge of nice clean cut so new stucco has a chance to fair in? Basic integrity of the whole stucco web is my chief concern; appearance matters much less on this utility porch at the rear of the home.
Here, a mixture of flex-con, an acrylic bonding admixture, and portland cement with no sand is painted on the join. The surface is left as rough as possible. This not only prevents edge cracking,
it avoids a nasty hump.