A17_Building Envelope Report.pdf

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Malmstrom AFB Dormitory 742 Enclosure Condition Assessment Preliminary Report

October 07, 2024 WJE No. 2023.8052.0

PREPARED FOR:

Page Southerland Page 1100 Louisiana Street, Suite One Houston, Texas 77002

PREPARED BY:

Wiss, Janney, Elstner Associates, Inc.

8000 Regency Parkway, Suite 410 Cary, North Carolina 27518

984.345.0630 tel

October 07, 2024 WJE No. 2023.8052.0

PREPARED FOR:

1100 Louisiana Street, Suite One Houston, Texas 77002

PREPARED BY:

Wiss, Janney, Elstner Associates, Inc.

8000 Regency Parkway, Suite 410 Cary, North Carolina 27518

984.345.0630 tel

Amy D Gelsone, AIA, NCARB, CIT, LEED AP Senior Associate

WJE No. 2023.8052.0 | OCTOBER 07, 2024

CONTENTS

Introduction Document Review Construction Documents Observations Interior Observations Exterior Observations Discussion Exterior Doors Windows Exterior Cladding Roof Closing Appendix A – Field Observation Diagrams

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INTRODUCTION

On behalf of the Malmstrom AFB 341st Contracting Squadron, Page Southerland Page (Page) requested that Wiss, Janney, Elstner Associates, Inc. (WJE) visually assess the existing enclosure systems at Dormitory 742 at Malmstrom Air Force Base, Montana.

Dormitory 742 is a three-story building, with a basement level mechanical room, currently including 26,900sf of twenty-six shared residential suites with shared lounges, offices, laundry, and storage.

The construction appears to generally consist of concrete framing with exterior wall concrete masonry unit (CMU) block infill. Though one drawing set calls for stucco over new CMU infill and the other set refers to existing exterior insulation finish system (EIFS), we believe the current condition may be a combination of the two. The 1996 set indicates that inboard of the CMU is an air cavity, felt, stud framing with foil-faced insulation, and interior gypsum wallboard. The windows are aluminum clad double-hung and the exterior doors are primarily hollow metal framed with some aluminum entry doors. Per the 1996 set, a standing seam metal roof was installed on framing added to the concrete deck of the original roof.

We understood from the Scope of Work (SOW) document that the exterior walls of the building were to be evaluated to determine whether any repair work is needed and the doors and windows are to be replaced. As described in the SOW, the existing gutters and downspouts are to be replaced. We understand that water intrusion is reported at the basement mechanical room.

Page requested that WJE assist in their evaluation by performing an assessment of visible existing conditions and developing recommendations for the items outlined in the SOW. To date, we have conducted document review and limited visual surveys. No exploratory openings or performance testing has been requested or provided. This preliminary report summarizes WJE’s observations thus far.

DOCUMENT REVIEW

Page provided WJE with documents for our review related to the reported enclosure issues. These documents include a set of as-built drawings titled “Renovate Dormitory 742” by Space Command, dated July 17, 1996 and a set of drawings again titled “Renovate Dormitory 742” by Space Command, dated April 11, 2008. WJE conducted a limited review of the provided documents as they relate to enclosure systems.

Brief comments regarding the content of these documents are provided below.

Construction Documents

The 1996 elevations call for stucco (Figure 1) while the 2008 ones refer to existing EIFS (Figure 2).

The addition of the standing seam metal roof over new framing on top of the existing concrete roof deck is described in the 1996 drawing set, as indicated in the building section on Plate A5.1 (Figure 3).

The eave detail indicates an internal gutter and partially internal downspout (Figure 4).

The typical window head detail from 1996 shows the window frame recessed inward from the surrounding construction with stud infill above the head (Figure 5) while the corresponding sill detail shows the existing sill construction to protrude beyond the rest of the window surround (Figure 6).

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Civil drawings from the 2008 set indicate reworking of the flatwork next to the west entry door (Figure 7), with the enlarged detail showing a grate in the same flatwork/location that extends to the threshold (Figure 8).

Figure 1. South elevation describing “stucco” over new CMU infill at west stair surround on Plate A4.1 of 1996 set

Figure 2. South elevation describing painting of existing “EIFS” on Plate A2.0 of 2008 set

Figure 3. Building section showing new roof framing system above existing deck on Plate A5.1 of 1996 set

Figure 4. New eave detail 3/A5.1 of 1996 set showing partially concealed downspout

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Figure 5. Detail 7/A2.2 of 1996 set showing windows recessed from exterior surround with infill above

Figure 6. Detail 7/A2.2 of 1996 set showing existing sill construction proud of remaining surround

Figure 7. Sheet C1.0 from 2008 set showing replacement of flatwork at west entry

Figure 8. Enlarged plan of flatwork replacement showing grate extended to door threshold

OBSERVATIONS

WJE personnel Amy D Gelsone, AIA and Daniel Chavez visited the site on May 7, 2024, with Amy Gelsone returning on May 9, 2024. The following sections present a summary of WJE’s observations of the exposed conditions during these visits.

Interior Observations

The following are interior observations of readily visible components from WJE’s above referenced visits.

Exterior Doors. We observed daylight below the south central double doors from the interior (Figure 9).

From the exterior of the same location, we noted that the fin was missing from the sweep mounted to the door exterior and the parge coat applied to the sidewalk below the sidelight was cracked (Figure 10). We noted surface corrosion at the base of the astragal (Figure 11), despite continuous weatherstripping gasket across the head (Figure 12). Similar surface corrosion was also noted along the latch side of one of the doors.

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At the west entry door, we noted active water intrusion during a rain event at a somewhat central portion of the threshold (Figure 13) along with fastener corrosion. From the exterior of the same location we observed that the water appeared to simply overtop the threshold (Figure 14). stemming from the concrete flatwork. A walk-off grate was located approximately 18 inches from the threshold.

Figure 9. Daylight visible from beneath south central exterior doors

Figure 10. Cracked parge below sidelight and missing sweep fin

Figure 11. Surface corrosion at base of astragal Figure 12. Brush gasket continuous across astragal

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Figure 13. Water intrusion at west entry door; fastener corrosion

Figure 14. Water overtopping the threshold

Windows. From our interior survey of the units made available to us, we noted many of the same issues among the windows. Screens were typically missing or severely damaged (Figure 15). Gaskets were severely deteriorated, missing, or delaminating (Figure 16 through Figure 18). We also noted that a number of windows do not operate properly, often failing to engage the locking mechanism at the upper sash and often sliding down from the top (Figure 19). In some cases the sashes were out of plumb (Figure 20), making it difficult to fully close them.

Figure 15. Severely damaged screen Figure 16. Gasket heavily deteriorated

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Figure 17. Gasket severely deteriorated and portions missing

Figure 18. Gasket delaminating

Figure 19. Upper sash sliding down from closed position Figure 20. Sash not plumb within window frame

Third Floor Ceiling Leaks and Attic. We noted evidence of two leaks through the ceiling on the third floor. In Room 323 the stained ceiling tile (Figure 21) was removed to reveal staining emanating from cracks/voids through the concrete deck above (Figure 22). In Room 326, staining was visible down the wall (Figure 23) and could be traced to what appeared to be a capped penetration through the deck above (Figure 24).

In the attic space, we evaluated the locations corresponding to the leaks noted below. With active rain at the time of our review, we were able to trace the leak above Room 323 to a panel clip for the standing seam metal roof (Figure 25). In the attic space above 326, we could not readily identify any moisture;

however, we noted a concealed downspout in the approximate location of the staining observed below (Figure 26). We noted that another concealed downspout pipe was broken (Figure 27), and there was a finding of typical displaced insulation with these concealed downspout locations.

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We noted other pipes in the attic space communicating between the standing seam metal panel roof above and through the original concrete roof deck, some exhibiting staining (Figure 28). It was unclear whether this staining was all from pipe adhesive or if water leakage also contributes. Unlike in Dormitory 735, no liner system was installed on the underside of the standing seam metal panel roof (Figure 29), and the vent through roofs appeared to be sealed only from above (Figure 30).

Figure 21. Ceiling stain in 323 Figure 22. Staining stemming from deck above stained ceiling tile

Figure 23. Staining down wall of 326 Figure 24. Staining traced to abandoned penetration through deck above

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Figure 25. Source of water intrusion identified above 323 Figure 26. Concealed downspout near staining in 326 and displaced insulation

Figure 27. Broken concealed downspout and displaced insulation

Figure 28. Staining on pipe extending through attic

Figure 29. Overview of support structure for standing seam metal roof

Figure 30. Vent through roof only sealed from above with boot

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Exterior Observations

The following are exterior observations of the readily visible components from WJE’s above referenced site visits.

Exterior Cladding. The CMU substrate behind the cladding systems was apparent at some locations during our visit, in part due to the recent wetting and differential drying at the body of the block relative to the mortar joints (Figure 31) and due to excessive and widespread cracking in the cladding systems at the CMU mortar joints (Figure 32). A vertical crack at the change in substrate between CMU backup and exposed split-faced block returns at outside building corners (Figure 33) was typically visible. Step cracks were also noted near windows (Figure 34), building corners, and in the field of wall. Cracks in the cladding coating were often observed at window surrounds (Figure 34). At portions near the east and west ends of the building, the visible cracking was generally concentrated in horizontal bands that appeared to correspond to floor lines, with notably few instances of other cracks here (Figure 35). Peeling of the outermost exterior finish coating and cracking extending through multiple layers of coating was noted on skyward facing sills viewed from the ground level (Figure 36).

At an isolated location of physical damage to the cladding, reinforcement mesh embedded in the cladding system was exposed to view (Figure 37). Other isolated incidents of damage included some blistering of the cladding system at a column (Figure 38) and on a wing wall (Figure 39). We also noted an instance of spalled split-face block (Figure 40).

Figure 31. Telegraphing of CMU wetting through cladding Figure 32. Cracks visible at CMU joints through cladding

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Figure 33. Cracks visible at CMU joints, particularly along vertical joint with split-faced block

Figure 34. Step cracks visible at CMU joints; cracks at sill-to-wall interface

Figure 35. Horizontal cracking along apparent floor lines at east and west ends

Figure 36. Peeling and cracking of coating extending through multiple layers on sky-facing sill

Figure 37. Damage revealing reinforcement mesh in cladding system

Figure 38. Blistering of cladding over column

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Figure 39. Blistering of cladding at wing wall Figure 40. Spall of split-faced block

Roof. We observed an instance of downspout strapping detached from the exterior wall (Figure 41) and noted that the downspouts at 742 appear to be tied into subsurface storm drainage. We also noted that the downspouts were fully visible from the exterior along with the gutters, some of which appeared to exhibit poor sloping (Figure 42). We also observed instances of standing water in the gutters (Figure 43).

The sealant at gutter joints was deteriorated and separating, and we noted at least one instance of separation between lapped metal ends at the exterior side of a gutter joint (Figure 44).

The fasteners generally appeared to be well secured and gasketed as viewed from nearby lift access (Figure 45). In attempting to locate the source of water intrusion above Room 323, we were not able to discern any distress near the standing seam clip that showed water intrusion below (Figure 46). At a panel near the east building end, we noted what appeared to be isolated buckling or possibly mechanical damage between roof panel seams (Figure 47).

Several of the flashing boots on the vents through roof had shifted and were no longer secured by the clamping ring in their original position. We observed sealant remaining on the pipe where the flashing boot would have originally terminated (Figure 48). On the lower roofs, we noted several instances of what appeared to be exposed insulation at the low roof interface with the upper roof eave, capping of at least one vent through roof on the lower roofs, and a noticeable difference in color between the roof metal of the lower roofs and the upper roof system (Figure 49). We also observed a bent vent through roof on a lower roof (Figure 50) but could not closely access it with the aerial lift to determine the effect on its flashing condition due to site obstacles.

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Figure 41. Downspout strapping detached Figure 42. Downspout and gutter fully visible from exterior; some sloping of gutter away from downspout

Figure 43. Standing water in gutter adjacent to downspout opening

Figure 44. Deteriorated sealant and separation at gutter joint

Figure 45. Fasteners generally well secured and gasketed Figure 46. No apparent distress above 323

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Figure 47. Isolated buckling or damage to roof panels Figure 48. Flashing boot and clamping ring have fallen from the line of initial installation

Figure 49. Exposed insulation; capped vent pipe; color differentiation of lower panels from upper roof

Figure 50. Bent roof vent

DISCUSSION

At this time, we believe additional investigation would be prudent and is recommended to further understand and assess existing system performance and promote success of the renovation efforts already planned for this project. We believe additional information is needed in particular related to detailing of the window replacement and adjacent construction, the vents through roof, some of which are capped, and abandoned concealed downspouts, one of which may be related to an ongoing leak in Room 326.

Exterior Doors

The south central entry doors appear capable of allowing air and water exchange, despite being under a covered canopy, due to missing fins at the sweeps and seemingly inadequate gasketing allowing the development of corrosion at the astragal and its anchor plate. It is unclear whether the cracked parge coat at the base of the sidelights is problematic from a weather management standpoint; however, the lack of

WJE No. 2023.8052.0 | OCTOBER 07, 2024 Page 14 any visible sealant at the termination of the threshold accessory indicates this condition is not weathertight.

The flatwork repair described in the 2008 drawing set does not appear to have provided positive drainage of rain away from the west entry door, and indeed water was observed to bypass the threshold at that location. The fasteners securing the threshold are also corroded and the bulb gaskets of the weatherstripping are damaged.

We expect that installation of new thresholds and weatherstripping with the doors can resolve most of the water intrusion through the exterior doors. The south central doors may benefit from the repair of the parge coat under the sidelights and improved sealing.

We did not sufficiently evaluate the issues contributing to reported water intrusion at the basement level mechanical room but will work with Page to understand and address the concerns there.

Windows

To develop robust detailing for the planned window replacement, we recommend that at least one exploratory opening be conducted at the exterior window surround. Based on our review of the drawings, it appears that the current existing conditions may have some added construction, possibly EIFS, that is covering the stud infill shown in the drawings, bringing the head and jamb surrounds flush with the face of exterior cladding.

Exterior Cladding

Given the telegraphing CMU backup and incidental opening provided by an isolated area of mechanical damage, the cladding system appears to be a direct-applied stucco with reinforcement mesh that has been recoated several times. Direct-applied systems are barrier approaches to water management and depend on essentially perfect continuity of the exterior coating to resist water intrusion. The excessive and widespread cracking is therefore preventing the exterior walls from performing as intended. Additionally, though we only observed a couple of blistered areas and some sky-facing areas of peeling, the build-up of even vapor permeable coatings can with multiple layers reduce the vapor permeance and associated drying capacity for any moisture that does get into the wall system. We intend to work with Page to explore options for removing the existing coatings and restoring the cladding surface to a smooth substrate for a finish coating that can restore the weather barrier function of the direct-applied system.

Roof

We understand that replacement of gutters and downspouts is already planned, which would be intended to address the associated concerns about standing water in the inadequately sloped gutters, sealant deterioration and separation at gutter joints, and detachment of downspout strapping. Beyond further investigation of and addressing the two leak locations, if the aesthetic considerations such as the color difference between the upper and lower roof systems and the patch panels pieces are deemed acceptable, we anticipate primarily addressing the deteriorated flashing boots of the vents through roof.

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CLOSING

The findings included in this report were based on visual field observations and limited analysis as described above. We are not including conclusions or detailed recommendations at this time as our investigation is ongoing. WJE reserves the right to modify our findings should additional information become available or if we perform additional on-site observations and/or testing.

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CLOSING

The findings included in this report were based on visual field observations and limited analysis as described above. We are not including conclusions or detailed recommendations at this time as our investigation is ongoing. WJE reserves the right to modify our findings should additional information become available or if we perform additional on-site observations and/or testing.

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APPENDIX A – FIELD OBSERVATION DIAGRAMS

© Copyright 2017. ALL RIGHTS RESERVED. NO PART OF THIS DOCUMENT MAY BE REPRODUCED IN ANY FORM OR BY ANY MEANS WITHOUT PERMISSION FROM WISS, JANNEY, ELSTNER ASSOCIATES, INC. (WJE). WJE DISCLAIMS ANY RESPONSIBILITY FOR ITS UNAUTHORIZED USE.

Wiss, Janney, Elstner Associates, Inc.

WJE ENGINEERS

MATERIALS SCIENTISTS

ARCHITECTS

TEXAS REGISTERED ENGINEERING FIRM F-0093

TITLE: FIGURE No:

MALMSTROM AIRFORCE BASE DORMS 735 & 742 RENOVATION

MALSTROM AFB, MT NORTH & SOUTH

ELEVATION X#

WJE No. 2023.8052.0

SOUTH ELEVATION

NORTH ELEVATION

D1.1

C Surface Corrosion at Fenestration

KEYNOTE LEGEND

Damage in Cladding AssemblyB Aged Bulb Gasket in Fenestration System

Interior Observations: Exterior Observations:

S Active Water Intrusion at Bottom of Fenestration Assembly

General Distress in Cladding Material

Surface Corrosion Staining on Cladding

Loose/disengaged Downspout Bracket

C

S

B

N Non-Operable Fenestration Unit

N

W Moisture Staining in Ceiling

SCALE: 1/16" = 1'0"

N

NORTH

KEY PLAN

SOUTH

Delamination in Cladding Material

Distress typically consisting of the following:

- Peeling of finish coat on cladding material

- Joints in concrete masonry wall substrate telegraphing through cladding in the form of cracks

- Isolated blisters in cladding material

© Copyright 2017. ALL RIGHTS RESERVED. NO PART OF THIS DOCUMENT MAY BE REPRODUCED IN ANY FORM OR BY ANY MEANS WITHOUT PERMISSION FROM WISS, JANNEY, ELSTNER ASSOCIATES, INC. (WJE). WJE DISCLAIMS ANY RESPONSIBILITY FOR ITS UNAUTHORIZED USE.

Wiss, Janney, Elstner Associates, Inc.

WJE ENGINEERS

MATERIALS SCIENTISTS

ARCHITECTS

TEXAS REGISTERED ENGINEERING FIRM F-0093

TITLE: FIGURE No:

MALMSTROM AIRFORCE BASE DORMS 735 & 742 RENOVATION

MALSTROM AFB, MT EAST & WEST

ELEVATION X#

WJE No. 2023.8052.0

EAST ELEVATION WEST ELEVATION

D1.3

SCALE: 1/16" = 1'0"

KEY PLAN

EASTWEST

Damage at east wall near gridline 18