Weep screed that is installed along the bottom of stucco walls is such a small piece of the overall stucco system and is barely noticed by most people, but is it required or needed at all?
We will dive into this question and give some real life examples of different situations that answer this question.
Is Weep Screed A Requirement?
I think the first order of business would be to talk about the codes regarding weep screed, which is used by many local county building departments across the United States. This code is taken from the International Building Code and it states that a weep screed shall be used for stucco and ran continuously (without a break) along the bottom of the wall.
Here is what it states exactly:
A minimum 0.019-inch (0.48 mm) (No. 26 galvanized sheet gage), corrosion-resistant weep screed with a minimum vertical attachment flange of 31/2 inches (89 mm) shall be provided at or below the foundation plate line on exterior stud walls in accordance with ASTM C926.
The weep screed shall be placed not less than 4 inches (102 mm) above the earth or 2 inches (51 mm) above paved areas and be of a type that will allow trapped water to drain to the exterior of the building. The water-resistive barrier shall lap the attachment flange. The exterior lath shall cover and terminate on the attachment flange of the weep screed.
In the above example, the first paragraph talks about how the weep screed is required and the second paragraph talks about minimum clearances from soil and concrete/asphalt surfaces, as well as attaching a water-resistant barrier and wire lath to the weep screed after it is installed.
Helpful Tip: The code that I grabbed in the above example is from a California code book, but is worded the same in the International code book, as well.
The IBC has different (updated) years so if you search for the code yourself, you may find different years associated with the international building code but the code on weep screed should be the same for all years and not change.
Is Weep Screed Required On All Walls?
Now that we know that it is "code" to have a weep screed installed along the bottom edge of your stucco, is that the case for all stucco walls? The answer is no, weep screed is not a requirement for all stucco walls, like masonry retaining walls.
If you have a concrete or cinder block retaining wall, then weep screed is not necessary. I have used weep screed along the bottom of walls, in rare occurrences if I want to use it as a guide to maintain a specific thickness of the base coat.
Weep screed is usually only required when an inhabitable space is behind that wall, in general.
Helpful Tip: In some cases, a weep screed is not needed if working on an older building that never used them and you are making repairs to an existing wall. It would look funny if you installed a weep screed on one wall of a building that did not have any installed on any of the other walls.
If this is the case and you are getting inspections, then it is generally pretty easy to get an exemption for this type of situation.
I Have An Older Home With No Weep Screed...
If you happen to live in a house that was built before weep screeds became a "thing" then you usually do not need to fret, unless problems are evident. I come across so many homes that do not have any weep screed in any of the walls and they are stuccoed all the way down to the soil, concrete or pavement.
If you are worried about not having weep screed installed or have an issue with your walls due to no weep being installed, then you would have to break out the stucco along the bottom plate, install the weep screed and patch the areas to install it, at that point.
Other Helpful "Requirements":
Even though weep screed is a required piece of the stucco system, according to code, it also has a couple of hidden purposes that most people don't think about.
It also provides a depth gauge for your material that you can use to obtain a uniform depth of your base coats and acts as a control joint along the bottom of the wall, which will eliminate any cracks from traveling past the weep screed itself.