What is weep screed? Why do we need it? These are questions that we found ourselves asking when a stucco contractor suggested it to us in order to solve a persistent moisture problem that we had with the exterior stucco walls of our house.
This topic came up again several years later when a friend asked the very same question as he was working on fixing up his new home.
So in this write-up, I wanted to address everything we’ve learned regarding our weep screed situation from the standpoint of a homeowner finding out the hard way, which is a point of view you don’t really see a lot of in the literature.
What Is Stucco Weep Screed (Or Drip Screed)?
Quite simply, weep screed is nothing more than a metal flashing placed at the bottom of the stucco exterior walls of your house (or any other building for that matter).
The following diagram (perhaps oversimplified) gives you a visual context of where it’s placed.
There are typically two types of weep screed – the #7 and “J” (note that in the diagram above, I drew a rather distorted J-type weep screed).
Each type is shown below.
The main job of the stucco weep screed is to allow water that manages to get behind the stucco wall to escape.
We’ll elaborate more on this idea in the next section.
By the way, for the purposes of this article, I’m only focusing on stucco as the exterior material for our home’s siding, which is common in Los Angeles (or throughout the southwestern states for that matter).
Other moisture-control strategies may be employed for other siding materials.
What Does Weep Screed Solve?
If you look at the oversimplified diagram shown above, you’ll see that the exterior wall of a house is built a very specific way.
This is primarily to allow water that manages to get behind the stucco wall to drip or evaporate, which in turn protects the underlying wooden structure of the house (or the home’s skeleton, if you will).
If water is allowed to accumulate behind the stucco wall, then that water will eventually wear down whatever’s back there (and I mean EVERYTHING – the stucco, the waterproof paper, the concrete, the wooden structure, etc.).
Put it this way, if the intent is to have a house that will last you a long time, these are not issues you’d want to undermine that longevity!
We’ve had the misfortune of experiencing blistering and flaking stucco, rotting (and molding) wood studs, and all the complications that come with these aspects of home construction unable to do their jobs!
So it’s really in your best interest to preserve the structural integrity of your house by managing how moisture moves through its sidings.
And to that end, the weep screed flashings give the water that manages to get behind the stucco an avenue of escape.
Water that would get behind the stucco wall would ultimately find its way down to the bottom through gravity, where the weep screed flashing would allow the water to escape.
The weep screed does this by letting the water drip (sometimes weep screed is called drip screed) through the holes at the bottom of the flashing though there should also be a sliver of opening between the flashing and the stucco exterior itself.
In addition to letting water leave the weep screed through gravity, the openings should also allow some ventilation to prevent mold growth as well.
How Does Water Get Behind The Stucco Wall?
Although stucco is said to be resilient and last around 50-80 years, we’ve personally experienced a situation where the stucco wall didn’t come close to lasting that long.
Moreover, we were also dealing with persistent water creeping up the stucco wall, which caused peeling paint (both outside as well as inside the house) and it ultimately weakened the structural beams of the house.
By the way, if you’re wondering how water creeps UP the wall against gravity, think about how water creeps up the tip of toilet paper or paper towel (a phenomenon known as capillary action).
Indeed, the main culprit behind our problems with the stucco walls had to do with water getting behind the stucco and staying there.
So how did the water get there in the first place (especially if stucco is supposed to be so resilient and long lasting)?
Well, it turns out that there are a number of ways that water can get behind the stucco and then accumulate if the water has nowhere to go.
Among the controllable ways that this can happen are:.
- Cracks in the stucco (emerging from temperature swings from hot to cold over time)
- Siding transitions (where stucco meets the windows, doors, roof, balconies, eaves, etc.)
- Gaps around pipes, lights, electrical panels, wiring, etc.
- Leaks from the roof and/or plumbing
- Improper, missing, or deformed flashing
- Soil and/or planters against the stucco walls
- Sprinklers spraying the stucco directly
- Excessive precipitation from storms (exacerbated by Global Warming and Climate Change)
On top of that, the job of the stucco exterior is to slow down the effects of the elements (sun, wind, water, etc.) and not be an invincible barrier.
In fact, stucco is porous so it actually tends to absorb water, which means there will inevitably be some water behind the stucco even if you’re not as affected by the ways water can get through as listed above.
So the bottom line is that water is an inevitable aspect of home construction, and how much damage the water does is directly attributable to how that water is controlled (or the lack thereof).
And that’s what weep screed manages to do for your home’s siding.
Do I Need Weep Screed For My House?
As you can see from our personal experience with our stucco wall not lasting nearly as long as the quoted lifespan of 50-80 years, we also learned the hard way that such complications messed with the wooden structure of the house.
In fact, for us, the stucco degenerated to the point that it crumbled and allowed water to get through the waterproof layer and start to bubble the interior paint of our drywall!
How can that be for something that’s supposed to last almost a lifetime?
After all, this house was built in the 1970s, and we’re in the year 2010 at the time!
And when we looked closer at the state of our stucco and how it got there, a huge hint to us that something wasn’t built right was seeing white “halos” or residue creeping up the siding.
This effect is known as efflorescence, and it was one way that Nature told us that we had better do something or else deal with another siding issue (and its complications) down the road again.
Strangely, I’ve also seen in the literature that some construction industry people swear by not needing to build weep screed.
However, in our experience, it was once we had the weep screed installed that we ded not have moisture-behind-the-wall problems that had plagued us before.
So I can’t speak to why our home without weep screed could have thrived without it, but I do know that having the weep screed is a no-brainer to us if we intend to keep the home for life.
What Is The Drawback Of Weep Screed?
Ever since we’ve put in weep screed, I can’t say that we’ve experienced serious drawbacks for having them.
In fact, managing moisture takes the highest priority when it comes to prioritizing home construction jobs, and thus installing weep screed properly in our siding is a no-brainer.
But there are a couple of complications that I can think of regarding the installation of weep screed.
First, having weep holes down there could mean the possibility of pests (especially termites as well as ants) getting through the hole and causing havoc from the inside out.
I suspect that weep holes at the bottom of weep screed flashings are large enough to let termites through, but I haven’t really seen issues manifested because of them.
If anything, in the case of termites, they’re likely to find other “easier” openings to penetrate the exterior and have at the wood.
So while it may not be feasible to try to fit some kind of cover with fine holes in the smaller weep screed holes (to accommodate ventilation while filtering out pests), it might make more sense to use this cover in larger holes.
The other issue was whether we already have a stucco job done without weep screed.
Unfortunately, we had just that issue, and we actually had to break the stucco, then essentially redo the siding with the weep screed installed.
That costed us more money than if we did the siding right in the first place (both jobs almost costed the same), and it’s yet another example of how haste makes waste or that cheaping out isn’t cheap at all in the long run!
I suppose the weep screed flashings can also rust over time, but the key thing is to let the house ventilate and try not block any of these openings or else risk dealing with complications of not having weep screed in the first place!
Indeed, the bottom line is that nothing’s perfect, but there are best practices to employ to make sure your home does what it’s supposed to do, and weep screed is one such best practice.
How Much Does Weep Screed Cost?
The weep screed flashing by itself is not expensive.
After all, if you look at Home Depot or Lowe’s or even Amazon, you’ll see that you can get the weep screed metal flashings for around $10-$50 or so for a 10 feet segment.
However, unless you’re a competent DIY-er (do-it-yourselfer), you’re probably going to have to pay the price of labor, and that’s where most of the cost lies.
In our case, we had a re-stucco job that was done before knowing about weep screed.
The first re-stucco job costed us about $3200 in the 2013 time frame.
However, when we saw the complications that happened without weep screed, then we had to break the lower parts of the stucco in order to have the weep screed put in, then re-stucco, and finally repaint it.
And that second job costed us $4000 as of 2017.
By the way, as you can see in the picture above, that second job always looks different from the first job unless you repaint the whole house even after years of weathering (about 4 years in our case).
It wasn’t until we applied a new exterior painting job that the obvious re-stucco band in the siding finally was concealed.
Anyways, as you can see, our painful experiences go to show you why you’ll want to get this job done right the first time to avoid this becoming a homeowner headache!
Final Thoughts / Conclusion
Like with a lot of things regarding homeownership, we often learn about home construction the hard way (usually unwillingly)!
And when it comes to weep screed, it was a foreign concept to us before, but now we know that it’s a critical part of proper siding construction on the exterior of a home.
In fact, it’s now a part of the California Residential Code (and I’d imagine it’s true for other states), which professionals are supposed to abide by!
That said, we lived with what happens when you don’t have weep screed or a properly-installed stucco siding on a home, and the end result was a huge lesson learned, which we’ve shared in this write-up.
Hopefully, what we’re sharing here makes you more wiser with your potential homeowner headache issues while saving you a lot of money!
Have questions or comments, please leave them in the comment box below…
You mention homeowners finding out the hard way not being present in most of the literature but isn’t that exactly how most homeowners become aware of a situations, the hard way? You have really done us a service in this writeup Johnny and I’m sure I’m not the only homeowner who is thankful.
I had never heard of weep screed before seeing the title of your article(that’s what got my attention and caused me to read it in the first place) but after your excellent description of how it allows any water that might have got behind a stucco wall to escape, at least now I have a solid understanding of what it is intended to accomplish. It’s actually the word “weep” that got my attention. Do got know the origin of the phrase or why it is called weep screed?
Thank you much for such an informative article.
Thanks for the feedback.
I suspect that weep screed got its name from its ability to get a home or building to “weep” out the moisture that gets behind a stucco wall.
Of course, it might also keep homeowners from having to weep (i.e. let out moisture from the tear ducts) from expensive home repairs by not having one?
As to the problem of termites & other critters getting in through the weep screed, I keep a 3-4″ clearance of vegetation and mulch below the ledge and spray with Home Defense up under the screed twice a year. This has kept termites, spiders and ants out of the walls and the house for 27 years now.
Sound advice Cathy! Thanks for the feedback.
The holes in the Weep Screed are not drain holes. The Weep of any moisture primarily occurs over the edge of the triangle-shaped part of the Weep Screed itself. The holes on top are Keyholes for Stucco to key into before it cures and draws away from the Weep Edge, creating a pathway for moisture to escape. There are other products out there that are intended to be drainage planes with actual drain holes, but that is not how Weep Screed works. This info is available out there, but there are a lot of people who have this wrong! All of your other observations are correct, and when a Contractor seals, caulks, paints, or waterproofs over the gap just below the Stucco and above the Edge of the Weep Screed, then, yea – your wall is screwed. Beware of anyone suggesting a Waterproof system. Walls, just like people, sweat / or condense b/c of relative humidity caused by changes in temp, whether caused by A/C or Heating or just general weather cycles. This happens everywhere – think of a cold glass of water on a hot day that gets your hand wet. If you don’t believe me, then start wearing a waterproof drysuit with no airflow around, and you realize Waterproofing unless you’re in freezing water and you need the heat is a terrible idea.
Thanks for the feedback and setting me straight about the weep holes.