I'm looking for some ideas on where a leak problem might be in our house
(mostly because I'm not sure about how concrete block walls are
constructed). We have a block house in FL built in 2001 (well, block up
to the bottom of the roof line then wood sheathing covered in stucco on
the gable ends of the house).
* The Problem:
One of the windows on that wall was leaking water from above it. This
happened once before, but only in the same circumstance -- when we have
a tropical storm and wind-driven rain is driven at this side of the
house. The wall is very tall there as the peak of the roof is straight
up from this window (there's about 10 more feet of flat wall abovce this
* My Diagnosis (so far):
Anyway, we noticed water dripping in though a hole in the sheetrock used
to mount a vertical blind rail. In order to diagnose it better, we
removed sheetrock above the window to see the source. The window has a
pre-cast lentil above it spanning the window and block all around it.
There is at least one course of block above the lentil that I can see (I
only removed enough sheetrock to see the start of the leak. Some fo the
mortar joints had small holes (approx 1/8") that seemed to be where the
water was seeking its way inside.
Looking at the lentil, it has blocks on top of it and there is mortar
between the sides of each block and under each block (between the block
and lentil). During heavy wind-blown rain against that wall, water is
"streaming" from the vertical mortar seams between the blocks above the
lentil, and seeping through the horizontal mortar seams between the
lentil and the block above it. The problem here is that once it gets
onto the house side of the block it gets the sheetrock wet, etc.
We also went into the attic and looked at the roof and wall above this
window -- nothing. Everything is dry as a bone during the middle of the
storm while the window is dripping. I can't see the top of the lentil
from the attic, though, There appears to be some horizontal wood down
the wall above the lentil blocking it's view. But everything I can see
as far down the wall as I can see is all dry, as well as the roof and
* What about this?
On the exterior wall where this window is we can see some type of
horizontal "joint" that stretches the width of the house, about 8 feet
up. We think it's either some type of expansion joint or perhaps a weep
screed, but I've not heard of weep screeps up that high. In any event,
It seem that this joint might allow enough water to enter behind the
stucco and (somehow) into the block, but we can't be sure. There must
be a lot of water pooling in the hollow block above the lentil because
it is dripping at a very fast pace. If you wipe it away it starts
streaming again immediately. I event tried squishing rubber silicone
sealant onto the holes in the mortar (from the inside) just to
temporarily plug the entry point, but the water seeped either through it
or around it and still came in at the same pace. It must be a lot of
water in there!
We looked for stucco cracks and saw a few "hairline" (at best) cracks
running vertically above the "joint" for about 3 ft. in length, but I
wasn't sure that such a fine hairline crack would let enough water in to
let it get inside the block and drip out like a fast-dripping faucet.
I was half-temped to drill into the block above the lentil just to see
if it drains out and see how much water is in there, but I won't dare
for fear of making the problem worse! <g>
Can anyone think of what might cause this much water to get inside the
block such that it is seeping into the house through the mortar? I've
heard it's normal for some water to get behind the stucco, but I thought
it was supposed to run down the outside of a water barrier and then out
the weep screed (which I thought was at the bottom of the wall). Is it
normal for water to get inside the conrete blocks that make up the wall?
If so where should this water go when it hits a solid lentil? I'd
greatly appreciate any ideas anyone might have as to why something like
this might happen.