Stucco soffit drip
We’re building a new house 1/2 mile from the ocean in Northern California (climate zone 3). The second floor overhangs the first floor by 4′ on three sides. We’re building a net zero energy house and so the structural floor cavity is filled with insulation and is not ventilated; taped plywood acts as our air barrier. We had detailed a weep slot between vinyl screeds on the horizontal edge so the water coming down the wall behind the vertical stucco thickness could get out, and this also provided a drip edge so the water did not return horizontally along the soffit. The scratch and brown coats of stucco are on and we just noticed the contractor did not put in any screeds – the stucco just turns the corner 90 degrees.
Are you concerned about water getting trapped and the framing rotting out over time? Is there anything you would recommend short of tearing out the stucco and replacing it? We were thinking of sawcutting a kerf all along the edges about 2″ in, not deep enough to nick the lath, but this doesn’t really provide a path for the water to get out…see attached
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Replies
User-7219789,
First of all, can you tell us your name? (I'm Martin.)
I think that a stucco weep screed is required by code -- perhaps another GBA reader can confirm that.
I think that it is the stucco contractor's responsibility to correct this error at the contractor's expense.
Thank you Martin, I'm Christine.
Here is an article I found about the importance of week screeds at soffits, even small ones at inset windows.
http://www.intres.com/wp-content/uploads/2017/07/Characteristics_of_Stucco.pdf
I double checked our building code in California and unfortunately it just talks about requiring screeds at the bottoms of walls along with the gap needed to paving or soil.
Water management aside, without a screed at that corner, the stucco will almost invariably crack.
Drainage at soffit overhangs is a code requirement.
ASTM C926 is specific: A2.2.3 Where vertical and horizontal exterior plaster surfaces
meet, both surfaces shall be terminated with casing beads
with the vertical surface extending at least 1⁄4 in. (6 mm) below
the intersecting horizontal plastered surface, thus providing a
drip edge. The casing bead for the horizontal surface shall be
terminated not less than 1⁄4 in. from the back of the vertical
surface to provide drainage.
This has been a requirement for a long time, so there's no excuse for skipping it. The good news is that it is relatively easy to fix at this stage. The contractor should chip back the stucco about 6" from the corner and cut away the lath, leaving a few inches of uncoated lath exposed. Install the casing beads, and tie the exposed lath to the expanded metal of the casing beads. Use some dash-bond to treat the exposed edges of stucco, then install the scratch and brown coats on the casing beads. Once you apply finish to everything, you shouldn't be able to tell a repair was made.
Thank you so much Peter, that's just what we've been talking to him about doing, though I didn't know about the dash bond.
This is a really great forum, I so appreciate all your fast responses!
Christine,
Coincidentally, there is an excellent article on this topic in the current (Nov. 2018) issue of the Journal of Light Construction. The article introduces a new term, "stucco bucket," to describe the error your house suffered. It's a useful term, so I'm going to adopt it for future discussions of this issue.
The article is titled "Avoiding Stucco Buckets." The authors are John Koester and Tyler LeClear Vachta. If you don't subscribe to the paper magazine, you can pay for an online subscription.