Diagrams showing possible penetrations in the south facing concrete wall--joints at floor and roof levels, previous louvers, and beam pockets.
Diagrams showing possible penetrations in the south facing concrete wall--joints at floor and roof levels, previous louvers, and beam pockets.
The blue arrows point to locations of concern in the photos that follow.
The blue arrows point to locations of concern in the photos that follow.
Evidence of moisture penetration at SW corner of machine room, in upper part of photo. 

Note also the blocked up louver at the bottom
Evidence of moisture penetration at SW corner of machine room, in upper part of photo.

Note also the blocked up louver at the bottom
Detail of previous photo, showing evidence of moisture penetration at SW corner of machine room.
Detail of previous photo, showing evidence of moisture penetration at SW corner of machine room.
Evidence of moisture penetration at base of blocked up louvers.
Evidence of moisture penetration at base of blocked up louvers.
A normal reading shows surface dry.
A normal reading shows surface dry.
A light rain and the reading changes to "moist" even though the wall still feels dry.
A light rain and the reading changes to "moist" even though the wall still feels dry.
A light rain and the reading changes to "moist" even though the wall still feels dry.
A light rain and the reading changes to "moist" even though the wall still feels dry.
Penetrations through the concrete wall on the south side, but not necessarily points of moisture intrusion.
Penetrations through the concrete wall on the south side, but not necessarily points of moisture intrusion.
Jeff's photo annotated

Note that second beam pocket was located in the next photo
Jeff's photo annotated

Note that second beam pocket was located in the next photo
Penetrations through the concrete wall on the south side, but not necessarily points of moisture intrusion.
Penetrations through the concrete wall on the south side, but not necessarily points of moisture intrusion.
Likely sources of moisture intrusion on the south side
Likely sources of moisture intrusion on the south side
Similar conditions at the East Tower with highly-visible joint at bottom of 12" slab
Similar conditions at the East Tower with highly-visible joint at bottom of 12" slab
Penthouse plans
Penthouse plans
Beam pocket detail


This detail is cut north-south, reversed from the next section
[This is cut south-north at South Tower]
Beam pocket detail


This detail is cut north-south, reversed from the next section
[This is cut south-north at South Tower]
Penthouse south-north section


Shows beam locations

[This is cut north-south at South Tower]
Penthouse south-north section


Shows beam locations

[This is cut north-south at South Tower]
Penthouse west-east section


Note tapered slab that directs rain to roof drain in northwest corner.
Penthouse west-east section


Note tapered slab that directs rain to roof drain in northwest corner.
Diagram of recessed areas at tower. But these do not appear at the penthouse, which was constructed in a different manner.
Diagram of recessed areas at tower. But these do not appear at the penthouse, which was constructed in a different manner.
This 60s aerial photo, of HW and HE, shows dark shapes in the penthouse south walls, which proved to be exhaust louvers over elevators 1 and 2 [HW] and 4 and 5 [HE], but which have been filled in with concrete block.
See diagram at top.
This 60s aerial photo, of HW and HE, shows dark shapes in the penthouse south walls, which proved to be exhaust louvers over elevators 1 and 2 [HW] and 4 and 5 [HE], but which have been filled in with concrete block.
See diagram at top.
The penthouse at South Tower shows potential problems at the roof line. See detail that follows for location.

[The louver locations do not appear in this photo, due to the low angle.]
The penthouse at South Tower shows potential problems at the roof line. See detail that follows for location.

[The louver locations do not appear in this photo, due to the low angle.]
Parapet detail above penthouse roof


This joint is visible in the South Tower photo to the left and may indicate a problem.
Parapet detail above penthouse roof


This joint is visible in the South Tower photo to the left and may indicate a problem.
The South Tower discovered similar issues. These three images document the north facing penthouse wall and the machine room interior.
The South Tower discovered similar issues. These three images document the north facing penthouse wall and the machine room interior.
South Tower: machine room interior.
South Tower: machine room interior.
South Tower: machine room interior.
South Tower: machine room interior.
These four images document the south facing penthouse wall and the other space interior.
These four images document the south facing penthouse wall and the other space interior.
South Tower: other space interior.
South Tower: other space interior.
South Tower: other space interior.
South Tower: other space interior.
South Tower: other space interior.
South Tower: other space interior.

Use the Zoom buttons in slideshow mode to see these images as big as you need.

Although there is no standing water or puddling, yet, at the HW [unlike at the HE] there is clear evidence of moisture penetration, even after only a light rainfall.

The first two images--elevation and sections--indicate the various locations moisture could seep through the south facing wall. The blue arrows locate the 10 photos that follow.

Additional resources are provided below to better explain how the penthouse is constructed. Note the abandoned louvers at both HW and HE, and presumably the South Tower.

Note that HE and the South Tower show evidence of similar areas of moisture penetration. [South Tower photos added 2-16-2022.]

HW moisture concerns at the elevator penthouse