stucco wall moisture leak

I realize that a properly constructed 3-coat stucco wall will have a weep screed
at the bottom to allow moisture to escape from the wall.

In my case, the builder put in an alcove into the rear exterior stucco wall of the
Casita. It is about 18 in deep, 8 ft wide and 8ft tall with an arch. Above the arch
it just goes up to the roof. There is a small soffit overhanging the wall, but it
doesn’t provide much protection from rain. There is no gutter there.

You probably need to see photos. I have them, just don’t know if I can post them.

Evidence points to water leaking into the house from the alcove under the wall where
the 3-coat stucco wall meets the slab. The exterior is painted with elastomeric paint.
(Sherin-Williams) The water gets under the wall and 2x4 stud base plate. You can see
a 3-4 inch stain on the interior side of the OSB sheathing. The water damage is at the
bottom of the interior drywall and molding. There was a little mold above the baseboard
in the closet which backs up to the alcove. The carpet in there just had a little water
stain, no mold. There is a shower on the other side of the closet interior wall and
at first I though that was the main culprit, but after taking out the drywall and
shower, I don’t think so. The drywall behind the three sided solid surface shower
panels was fine as was the insulation behind it. The shower plumbing isn’t leaking.
(Single Delta T13020) I capped the shower pipe and turn it on and there are no
leaks in the copper plumbing. There is just the stain on the exterior OSB about
3-4 inches above the 2x4 stud wall base plate. It’s all along that exterior wall.

The shower pan/drain is another issue. When they framed in the 36x36 shower stall,
the PVC pipe that came up through the slab did not line up with the fiberglass
shower pan, so I think they just jack hammered out a 8x12 inch square around the
2-in drain pipe and put in two 12 degree bends to get the pipe to line up with the
shower pan. The drain wasn’t secured very well to the shower and the pan had mold
spots on the bottom of it. However, the 8x12 inch hole around the pipe is about 8
inches deep. and down to soil/gravel. Yes, water was probably leaking around the
pan shower drain, but I do not think it was the source of water that ran along the
exterior wall and damaged the drywall. The plumber didn’t leave enough pipe extending
up to the shower pan to properly seal the shower drain on the pipe with the rubber
bushing. It had silicone all over it and the drain was not attached properly to the
bottom of the pan. I am fixing the shower drain pipe and will fill it in with concrete.

Okay, back to the exterior wall. Water could have gotten in from rain. There is a
questionable roof design there Where the Casita roof meets the breezeway, (That is yet
another project) but I didn’t see evidence of any water entry above the base plates.

Confession: I had a 3-gal pond bio-filter sitting in the alcove. (TetraPond PF1)
It could have leaked, or overflowed. I had a dog that liked to mess with the hoses
a number of years ago. I haven’t seen a puddle of water in the alcove recently.
It was probably the pond filter hoses. I have moved filter out to below the alcove
on the ground. The slab that makes up the alcove is about 8 inches above the ground
and about 5 inches from an in-ground pond. It is one of those 125 gallon plastic
dog-bone ponds.

Question: How do I best solve this moisture problem in the alcove? The wall has no
weep sceed. It just meets the slab with no gap. It may have been caulked at one time.
The house was built in 2001.

  1. Should I cut the stucco up an 3/4 inch or so being careful not to cut the tar paper
    underneath and not over the stud base plate? Then seal the baseplate to the slab, then
    use a concrete resurface product to grade the slab in the alcove away from the wall?
    That seems like the most sensible solution, but more work.

(Actually, removing the alcove and making it a wall would probably be the best
solution, but I can’t do that.)

  1. Or use the “Remedial Treatment for a Missing Weep Screed” found at:
    (Good information, but I think it assumes the vertical wall can drip down outside
    of the slab.

  2. Do #1 cutting the wall up high enough to put in a weep screed. Not sure thare is
    much advantage in doing that.

  3. Simply reseal the bottom of the wall to the slab with silicone/sealer. I do not
    like this because I would still still have the problem of moisture not being able
    to escape as it should. I guess I can repaint the wall with the Elastomeric paint
    and maybe use some of the rubber seal spray inside and out, but that seems like a
    short term patch.

  4. Remove the alcove and make it a flat wall that overhangs the slab with a proper
    weep screed. Yeah, but I cannot afford to reframe that house. Of course, I would
    get more closet space!

Sorry for the long post, thanks for reading all this.

Put the photos on something like Photobucket and post the link.

You also seem to have more than the common knowledge about the building trades.

Recommend to contact a qualified home inspector, or contractor, in your area, experienced in stucco application.

Yes, I need some help figuring out what is the best thing to do
to fix this. I’ll look for an inspector. Or should I be looking for a
contractor with stucco experience… maybe from the local NARI?

Here are some photos for the curious.