Post on 23-Feb-2017
As provided by: Timothy C. Johnson
Ballard Condos Site Visit for Work Proposal by Belltown Coatings
Membrane Damage
We looked at one location where
water has worked its way beneath
the membrane at the second level
outer concrete deck. Following
picture is between drain and outer
wall.
27 September 2012
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Water Blister
It appears water became trapped
under the membrane between the
drain and the deck-to-wall
transition, and eventually cracked
the membrane open. Water was
present under membrane at time of
site visit.
27 September 2012
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Probable Source
Wrought iron planter support near
water blister appears to have
punctured through membrane,
creating path for introduction of
water beneath membrane.
27 September 2012
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Closer View
Manager said there were 3 or 4
similar locations of membrane
damage at other parts of the
second level outer concrete deck,
but we only looked at this one,
because other locations would
require going through occupied
units, and we had not made prior
arrangements. Other locations
could have similar causes, or
something else. We could propose
limited scope repairs at these
damaged locations, and we could
make arrangements to view the
other locations to see the nature of
the problem at those locations.
27 September 2012
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Cracked Membrane
Water appears to have followed
unprotected vertical cold joint cast
into parapet wall at inside corner
down to structural and likely
additional over-cast sloped or
cricketed topping slab, behind and
under waterproofing membrane.
27 September 2012
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Substantial Crack
Membrane has cracked open along
ridge line or screeded high point of
probable topping slab cast over
structural slab. If this location
marks cold joint of two separate
pours of topping slab to screed from
this line to nearby drains, then
differential movement between
these two separately poured
sections of the topping slab could
easily crack open the membrane at
this location, and allow water to
travel down through the topping
slab sections, and eventually to the
drains in the structural slab, causing
efflorescence around them, etc.
27 September 2012
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Closer View
This crack through the membrane
along the ridge line of the topping
slab is immediately adjacent to the
unprotected vertical cold joint in
the outer parapet wall, and the
latter has almost undoubtedly
contributed to the severity of this
situation. Scope of repair should
address both problems. Last phots
in this report depict the parapet
wall cold joint, which should be
capped and protected.
27 September 2012
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Additional Cracks
Other smaller cracks spin off the
main one at the crest of the
screeded high point or ridge line in
the topping slab. These tend to be
less severe, but should be
addressed as well. Affected area is
therefore potentially several feet
wide, and eight or ten feet across
the deck width.
27 September 2012
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Parapet Blown Out
This crack in the parapet is not the
actual unprotected cold joint, but
likely marks where water has
followed rebar down into the
concrete and then with freeze-thaw
cycles has blown out the concrete
vertically on this face. This damage
aligns exactly with the long, main
crack in the concrete deck
waterproofing previously depicted
in the above photos. This vertical
area could also be sealed with a
PMMA patch, etc.
27 September 2012
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Conditions Below Crack
As expected, water has worked its
way down through the topping slab,
travelled along the structural slab,
and then worked its way around the
drain bodies nearby, particularly
this one, nearest the unprotected
parapet cold joint above.
27 September 2012
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Efflorescence on Walls
Evidence of water travel also
appears at cold joint between rising
vertical cast concrete wall and
structural concrete deck above,
possibly from same source. Or
water stop could be missing at this
part of this cold joint, etc.
27 September 2012
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Water around Drain
Another view of evidence of water
attacking drain body from the
outside, i.e., from the upper surface
of the structural slab, beneath the
topping slab.
27 September 2012
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Inside Corner
This location aligns with the open
cold joint in the cast parapet wall
one floor above, and this type of
water presence reportedly carries
down another level at the same
location, to the interior of the main
electrical vault. Hence some of the
interest in shutting down the source
or sources of this water travel.
27 September 2012
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Same Location
Evidence of water travel carries
pretty much all the way down the
wall, at this level. It would seem
that in order for water to get from
the parapet cold joint to here, or
from the nearby drain bodies to
here, it would have to travel along
the underside of the structural slab,
or through cracks in same, which, if
they exist, could be concealed by
the rigid insulation covering the
underside of the slab at this location
(see above photo). If such cracks
exist, they could comprise a serious
structural issue.
27 September 2012
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Upper Wood Decks
We then looked at one of the
southern exposure upper wood
decks. Cracks have developed in the
coatings on many of these decks, as
well. The manager was thinking
that as many as 50 decks could be
affected by this condition.
27 September 2012
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Closer View
Cracks through the coatings appear
to be somewhat random in size and
direction, and no likely cause for
most of them was readily apparent,
at the time of this site visit.
27 September 2012
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Midpoint Lateral Crack
Many of these southern decks
appear to have a larger crack
running from the center of the glass
slider to the outer edge of the deck,
which could correspond to a seam
in the underlying plywood. Deck
also appears to be crowned at this
location, so that water will flow left
and right from this line, as well as
out to outer edge.
27 September 2012
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Overview of Main Crack
Here is an example of such a crack
through the membrane. These
decks were all recently coated, a
few years back (2007 or 2008, if I
remember correctly), but those
taking the most weather seem to be
failing systemically, usually with
cracks like this one.
27 September 2012
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Another View
I had suggested that repairs only at
the cracked areas might not be
possible or productive, nor likely
aesthetically pleasing, and that
therefore affected decks would
most likely need to be completely
recoated, likely with new
reinforcement at cracked areas.
27 September 2012
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Similar
Decks vary in size and configuration,
but probably average about 8 x 12
or 8 x 15, sometimes with extra jogs
or bends around vertical rising
columns, etc.
27 September 2012
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Crack at slider
As mentioned above, main center
crack seems to follow possible high
joist beneath sheathing, or possibly
seam in plywood, and returns
basically all the way back to the
deck slider.
27 September 2012
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Scope
Manager wasn’t sure exactly how
many decks are affected, and I
believe he was thinking about
putting out an inquiry flyer to get
feedback from the homeowners
about their individual deck
conditions, etc. He may have more
exact info, by now, regarding scope,
number and size and shape of decks
needing repair coatings, etc. We
were only able to look at one deck
closely, because again we did not
have prior arranged permission to
enter other units, but we could see
several others from this deck that
seemed to evidence similar
problems.
27 September 2012
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Concrete Deck
Here is an overview shot of the
concrete deck area above the
drains with all the efflorescence
down in the parking garage, where
the crack through the membrane
runs across the deck from left to
right on this side of the depicted
drain.
27 September 2012
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Concrete Damage
Closer view shows overview of
vertical concrete damage probably
related to water following rebar or
other path down into wall and then
blowing the wall out by freezing,
etc.
27 September 2012
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Closer View
Note that this damage seems to
provide the most likely path behind
the installed membrane below
(fluid-applied deck-to-wall flashing
has blown off wall and has air or
water behind it, at this location),
and as indicated earlier in this
report, aligns with main lateral
crack through membrane at this
concrete deck level.
27 September 2012
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Actual Cold Joint
On the other face of this same cast
inside corner you can see the actual
cold joint between successive pours
in the constructed concrete parapet
wall.
27 September 2012
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Plan View
Same unprotected cold joint, as
viewed from directly above. It
seems likely that water entering
here has helped to create blowout
to the right, below.
27 September 2012
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Repair Scope
Scope of repair should include a
well bonded cap over this area,
possibly extending out onto either
leg of the top of this wall about a
foot, and turned down the sides,
probably utilizing an excellent
primer and a PMMA fabric-
reinforced field constructed boot or
saddle over the entire area.
27 September 2012
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Cold Joint
This construction joint also extends
down the outside face of this angle
change in the cast concrete parapet
wall. This vertical area could also be
sealed, and definitely ought to be,
even though the top face is
obviously the most critical.
27 September 2012
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Cost Saving Options
I mentioned PMMA, as a possible
excellent long-term fix for this
problem, but I thought if well
primed, a high quality peel-and-
stick flexible flashing material or
self-adhering membrane like Ice and
Water Shield or Vycor could also
work, if covered by a one-piece
soldered or welded stainless steel or
galvanized coping metal saddle or
boot. The manager was also
thinking about attempting repairs at
this location himself. I believe this is
the key, or lynch-pin, for all of the
problems below it, all the way down
two levels to the electrical vault
below.