Thread: Gaps underneath stucco weep screed vertical drainage plane

Have a question and not certain that anyone can properly answer this. I have a few homes that we have notice a gap at the bottom of the weep screed.
Here is the scenario- Wood framed home with stucco installed at exterior of home. House is a production home with shear wall panels 1/2 plywood/osb installed at random locations(value engineering). The concrete is a post-tension desgin and the stem walls are perfectly straight. The stucco contractor used #7 7/8" weep screed at all locations of home that do not have shear panels. Where the home has shear panels the stucco contractor changed the weep screed to a #7 3/4" weep screed. By utilizing these two different sizes of weep screed the contractor was able to maintain a straight line of stucco on the wall. Wall is not wavy and it is entirely uniform.

Here is the problem--- by utilizing the different weep screeds the contractor did not account for the different sizes of the lower flanges on the weep screed. Now the entire section of the weep screen has a gap that is about 1/2" to 3/4" in thickness that allows for bugs to crawl up underneath and pests as well. It appears that all stucco weep screeds are built with both "V" sections of the flanges equal. There is no type of weep screed(that i know of) that has a "V-A" measurement and "V-B" measurement.

Please advise of the following. 1---Is there a manufacture that allows for different weep screed sizing (different v-section measurements) being utilized on the same wall construction with different flanges due to elevations in horizontal wall planes. It current appears that there is not. And in the current production environment not alot of effort has gone in to this type of construction design. 2-- Is there an alternative method to correcting this besides tearing into the wall or caulking it??

Please advise

Daniel Martinez


Thank you

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Short answer is yes, they do make a screed that reaches back 1/2" past the sheathing to the stem wall face. I don't know for sure who makes it. you could try Stockton, Amico, or Keen Products. We have been using it for several years.
As for a recommended fix, I'm not sure there is one, the reason for the screed in the first place is to allow drainage of moisture from the vapor barrier, so you don' want to caulk that up....it would be bad. Very bad. The older screeds had 1/4+ holes punched in the lower flange, so I'm not sure insect access was considered a problem they had to address.....oh, well.

Sounds like they are using control joint grounds instead of foundation weep screeds.

Go here: AMICO Metal Lath and Vinyl Bead Building Products > Products

and here: AMICO Metal Lath and Vinyl Bead Building Products > Stucco Foundation Weep Screed

no- they are using foundation weep screeds. The picture on the second link describes it the best. IF you look at the second picture on the second page. do not look at the top nailing flange, look at the lower section, the ground portion (sideways v). Every single manufacturer makes this section with equal lengths. if you look they set the shear panel so that it is flush with the stem. In Arizona we do not need to shear an entire house.(no hurricanes, mudslides,eathquakes or chupacabras). So only the value engineered sections of the home are sheared. So typically the bottom plate of the house is installed flush or on same vertical plane as the stem wall. when you have a section 4' or 8' etc. of shear panels that need to be installed they change the size of the weep screed to compensate for the protrusion in the wall and to make the exterior plane of the wall flush.

I know that this may only be an Arizona issue(due to heavily relaxed codes based on environmental conditions). Does anyone know how to fix this????

Thanks for the link it was actually very helpful

Daniel Martinez

I know that this may only be an Arizona issue(due to heavily relaxed codes based on environmental conditions). Does anyone know how to fix this????


Daniel Martinez[/QUOTE]

I have gotten results, for customer, from the builder [ they cut weep and over layed exitisting] by writing up, protect exposed wood from moisture- pest damage, or seal large gap to prevent scorpion, rodent entry.

50% chance the builder will correct it, sometimes higher if the lady customer presses the scorpion or rodent entry into home issue
From my exp the ROC will not enforce closing the gap.

If the customer is not succesful with that info, I recommend to the customer to fill the gap with steel wool.

What do you recommend for the rust stains that surely will develop later??
Sometimes you guys are too easy...

Originally Posted by John Carroll

What do you recommend for the rust stains that surely will develop later??
Sometimes you guys are too easy...

I agree, it's frustrating, especially in the 55 plus sub divisions where the little old ladys get together and talk.
The builder will seal, or reseal, around the freon lines with no questions asked, present an area with a larger gap that can only be seen with a mirrow, the heck with that, that's normal, we not required to seal there.

I found this original post from Daniel Martinez and I wanted to reply to it even though it is several months old. I would like to introduce to you a product on the market known as Universal Weep Screed.

It is a vinyl product that was manufactured to address the problem that arises when the sheer panel is installed to the framing which is flush with the foundation. As you probably have found at times, the Weep Screed is then installed over the sheer panel only to leave the bottom of the sheer panel exposed or leave a gap between the weep screed's lower edge and the foundation itself.

The Universal Weep Screed accounts for such details by having a longer return flange at the base of the screed which allows it to rest against the foundation, thus overcoming the added thickness of the sheer panel.

Check out this website to view the product and see what I mean.

Flannery Inc.

Thanks, Bud

Hello,
I'm buying a house that was built in 1987 in Prescott, Arizona. It is in escrow and during this inspection period, my home inspector found that no weep screed was installed. I called the city planning office and they said this house was most likely built back when weep screed installation wasn't mandated; it was mostly a luxury. The house has passed all other inspections: Mold,termite infestation, etc. Should I be concerned? Does any one know what recourse do I have if the home passed inspection back in '87 and now it won't?

Originally Posted by rlstevens

I called the city planning office and they said this house was most likely built back when weep screed installation wasn't mandated; it was mostly a luxury. The house has passed all other inspections: Mold,termite infestation, etc. Should I be concerned?

First, to my knowledge, back in 1987 it was a requirement of the standard by which stucco was to be applied.

The city may not have been aware of it, but that is a different issue.

Does any one know what recourse do I have if the home passed inspection back in '87 and now it won't?

Your only recourse would be to either not buy it, have the seller correct it (at great expense), correct it yourself (same expense), or leave it and take as much credit from the seller as you can get - then make sure you write a seller disclosure to include with a future sale which discloses that issue to future prospective buyers so you will not have to pass the money on.

Should you be concerned?
- Yes, as it does not allow the wall system to drain properly.
- Not a lot if there is no evidence of leakage or seepage into the walls and no damage to the structural framing after this 20+ years - without destructive inspection (making holes in the interior walls) there is no way of knowing if the problem has raised its ugly head.
- Yes, that indicates that there may have been other things *not done* which should have been done with the stucco installation, such as only one layer of paper instead of two (the first layer is a bond breaker, the second is the drainage plane), using the wall sheathing as a drainage plane could cause the wall sheathing to decay and rot out.
- Not much as stated above if this has not happened, you would need the destructive inspection into the walls to find out.

If you had a good home inspector who spent the time, and had the knowledge, needed to look for the evidence of the problems which are created by lack of weep screed, then if no evidence was found, you may have lucked out.

Besides, your environment is mostly dry, compared to areas of the country where it rains a lot, and that in and of itself would reduce the damage simply by reducing the amount of rain on the walls.

The Metal Lath Handbook by Gary J. Maylon

Here's an article about weep screed's, building code's, etc. I'm not sure how accurate it is.

Originally Posted by Brandon Whitmore

Here's an article about weep screed's, building code's, etc. I'm not sure how accurate it is.

This is the part I see which is wrong: (see underlining and bold)

As mentioned earlier the foundation weep screed is the first accessory installed and should be placed over grade D building paper or a strip of building paper flashing. The second layer of building paper or the paper backed lath is then installed over the back flange of the screed to the top edge of the angular screed. In this way any moisture that makes its way through the cementitious membrane to the building paper will by way of gravity be drawn to the bottom of the wall and flow over the angular screed and exit via the drip screed. In this way we have several redundancies that will help to prevent moisture from penetrating the cementitious membrane and the weather barrier. We must keep moisture off of the sheathing and out of the wall cavity.

That first layer of paper or WRB is the drainage plane covering the sheathing behind it, and, as the drainage plane that first layer of WRB needs to lap *over* the weep screed, not be placed *under* the weep screed as stated above.

With the weep screed placed *over* the WRB (i.e., the WRB *under* the weep screed), there is no need for the weep screed, the water will try to work its way down behind the flange of the weep screed, mostly not working very well.

With the weep screed placed *under* the WRB (i.e., the WRB *over* the weep screed), the water draining down the drainage plane (the first layer of WRB) flow down and over the flange of the weep screed, exiting out the gap between the stucco and the angled cant of the weep screed as explained in that article. Also, as that article states, the holes in the weep screed (when there are holes in it, there are two types of weep screed - perforated with holes and non-perforated with no holes) are there to allow the stucco to be forced into and through the holes, keying the stucco to the weep screed angled cant.

The the second layer of paper is installed or paper backed metal lath is installed, and it also goes over the weep screed over the first layer of WRB.

What holds the stucco in place at the weep screed?

Two things: 1) the lath is fastened to the wall and the stucco is keyed into the lath; 2) the stucco is keyed into the perforated weep screed - when perforated weep screed is used, otherwise it is just 1) which holds the stucco in place. That is okay because the only thing which holds the stucco in place on the rest of the wall is 1) anyway.

"7.1.3 Portland cement-based plaster shall be applied on
furred metal plaster base when the surface of solid backing
consists of gypsum board, gypsum plaster, wood, or rigid foam

board-type products."

I'm starting out with this quote from ASTM standard C-926, Standard Specification for Application of Portland Cement-Based Plaster to illustrate the reason that ASTM 1063 mentions wrb's only in passing and in only one paragraph at the end of the specification.
In The Beginning, plaster was always intended to be applied to a metal base (wood lath being employed only because metal was not readily available when JP and I were kids). It was always applied in a manner similar to old style brick veneer, with an air space between the structure and the plaster membrane. This space became, effectively, the drainage plane.

Modern techniques evolved to reduce this space, or eliminate it entirely, by adding a "membrane", (fancy name for a WRB) to direct inadvertent moisture away from the underlying structure (wood, usually), that tends to react poorly when exposed to excessive or prolonged moisture.

Properly applied plaster bases are indeed, quite watertight, in fact, it takes a great deal of sustained, wind driven rain, over many hours or days to get even a small amount of water to penetrate properly mixed, and densified cement and lime plaster. There are several test results posted on the web that testify to this capability.

Problem is not the plaster, but the MUCH cheaper window and door systems employed in modern (post 1960) construction. Back when the plaster was furred out away from the structure, WRB's were not required, and hence, their notable absence in both ASTM C-1063 and C-926. (Bond breakers are not even mentioned.)

Weep screeds have always been required to allow a gap for moisture to escape, and also to help ventilate the cavity between the plaster and the structure to promote a drier space. How do you ventilate a tight gap where the lath and paper is pressed up against the structure? Answer is, you can't. But it is MUCH cheaper to install than that clunky old metal furring...in the short run.

I hate to burst your bubble, but this single quote from C-926 negates anyone's claim to have installed lath according to C-1063 without furring the plaster off of the structure and providing a drainage cavity. WRB's are for scam artists and cheapskates, which is what this industry has become, sadly...

Sorry if this doesn't address the question, my only intent is to point out some long forgotten history related to the debate. Those who forget history are doomed to stumble along repeating it, or something like that...

Originally Posted by John Carroll

In The Beginning, plaster was always intended to be applied to a metal base (wood lath being employed only because metal was not readily available when JP and I were kids).

John,

But bronze was all the rage back then.

Very good post with excellent information.

You should look at what the guy on stuccoguru.com had to say about this situation (Click Below):

Remedial Treatment for Missing Weep Screed

WEEP SCREED INSTALLATION

Hope this helps.

Maybe I am misunderstanding the original post, but I believe the answer, short of originally placing the wall correctly in relation to the foundation edge, is this:

AMICO Metal Lath and Vinyl Bead Building Products > Stucco Weep Screed Extended Leg

test reply

Originally Posted by Doug Wolfe

test reply

DW: Test reply to test reply.

Originally Posted by A.D. Miller

Maybe I am misunderstanding the original post, but I believe the answer, short of originally placing the wall correctly in relation to the foundation edge, is this:

AMICO Metal Lath and Vinyl Bead Building Products > Stucco Weep Screed Extended Leg

All these extended leg products seem to make the "air gap" principle of the original design non-functional.

Originally Posted by Philip Ngai

All these extended leg products seem to make the "air gap" principle of the original design non-functional.

Could you direct me to information about the "air gap principle"?

Originally Posted by Bud Rutherford

Could you direct me to information about the "air gap principle"?

Drip Edge & Nosing
Installing Drip Edge on Utility Shed - Repainting Utility Shed

Also look up capillary action.

JEEZ, who are these nimwits...Neither of the last two posts addresses the original question. YES, there is a proper weep screed to address shear panels. It's called offset return sill screed and is quite common in this area. See the literature available from Superior, Amico or Keene.

By the way, A.D, was banned for a reason, he is a dumbass.