Att_07_Assessment_Report_10-04-2019.pdf

CONDITIONS ASSESSMENT

REPORT

Big Sky, MT | Fort Collins, CO | Tel 206-549-2149 | morrisonhershfield.com

TO: Dennis Johnson and Matt Morgan, A&E ACTION BY: Project Team

FROM: Jack Pearson & Kelly Sabrowsky, MH PROJECT No.: 190470900

RE: Yellowstone National Park Laurel Dormitory Rehab DATE: 2019-10-04

Team, MH is issuing this document as the full conditions assessment report that includes the previously issued crawlspace memo information, additional assessments, and recommendations for the whole building.

1 Background

Morrison Hershfield (MH) was retained by A&E to assist in conducting a conditions assessment report on the Laurel Dormitory located in Yellowstone National Park, Wyoming. The objective of the investigation was to attempt to determine the cause of the reported issues and work toward a plan for resolution. Our understanding is that the primary issues center around elevated moisture content, microbial growth, and material degradation in wall and floor assemblies.

Consequently, the National Park Service has requested recommendations for resolution specific to the crawlspace and rehabilitation of the building enclosure as a whole.

2 Assessment Methods

The initial on-site investigation was completed on August 26th, 2019 by Jack Pearson and

Kelly Sabrowsky of Morrison Hershfield. Dennis Johnson and Kate Geer of A&E and Kip

Weeda of Associated Construction Engineering (ACE) were present for the assessment.

The fieldwork included visual and infrared review of exterior and interior elements of the

Laurel Dormitory including the crawlspace, first and second levels, vertical walls, attic, and roof. Hygrothermal data loggers (temperature and relative humidity) were placed at multiple exterior, interior, and crawlspace locations to attempt to gain an understanding of the interactions, if any, between the different environments. A follow up on-site investigation was performed on September 9th, 2019 by Jack Pearson and Kelly Sabrowsky. The data loggers were collected and additional visual observation of the building was performed.

3 Assessment of Current Conditions

The following sections outline the observations from the assessment of the building enclosure. Current conditions were evaluated from past reports provided by A&E, field assessment, and analysis of data collected by hygrothermal data loggers. Each section contains a description of the specific review, general findings, and imagery with captions showing specific findings.

3.1 Crawlspace

MH observed the condition inside the crawlspace and specific findings were as follows:

1. The existence of a geothermal feature beneath and adjacent to Laurel Dormitory was noted to be a source of significant heat and humidity into the crawlspace. There was no vapor retarder installed on-grade within the crawlspace, nor was there any barrier to heat, air, or moisture vapor between the crawlspace and interior spaces above.

2. Multiple plumbing leaks were noted in the crawlspace that provided another source of moisture and moisture vapor due to evaporation. Corrosion was noted on the majority of non-galvanized plumbing components presenting a risk of further plumbing leaks and resultant issues.

3. The third observed source of moisture into the crawlspace was bulk water leaks from at/below grade through foundation wall cracks, penetrations, and block-outs. This water intrusion was contributing to elevated humidity levels within the space, peeling/bubbling paint off of the interior side of foundation walls, and causing structural damage to posts and framing. It was noted that damage to structural posts has been previously identified and repaired in some places but missed in others.

Painted wood had held up better against the moisture than unpainted.

4. The alcove at the inside corner of the building appeared to be an area of water accumulation that was entering the crawlspace on all sides. It appeared that some of the water intrusion was the result of water flowing off the above roof with significant force causing it to splash up and enter through foundation block outs and cracks.

5. Active ventilation installed on the north elevation had a positive impact in the vicinity of the fan, but was inadequately sized and distributed to be effective throughout the entirety of the space. The ventilation is deactivated in the winter, resulting in the space only being passively ventilated for a large portion of the year through incompletely screened block-outs in the foundation walls. The passive ventilation system was frequently blocked with insulation boards and placed at a level that would be blocked by snow drifts.

6. The foundation wall was variably cracked in numerous locations suggesting that there may be concerns about structural settlement beyond typical cracking of cast-in-place concrete walls.

7. Evidence of significant pest intrusion through the foundation walls was noted at penetrations and incomplete screens installed at block-outs.

8. The fire riser penetrated the crawlspace ceiling without any air or moisture-vapor seal. This and other unsealed penetrations to the interior, occupied space above provided opportunities for air and vapor flow into the enclosed and occupied space.

Figure 1. Infrared image showing thermal bridging at foundation wall below stairs indicating that the crawl space is hot relative to the rest of the building

Figure 2. Corresponding visible light image to Figure 1

Figure 3. Infrared image showing thermal bridging at foundation wall indicating that the crawl space is hot relative to the rest of the building

Figure 4. Corresponding visible light image to Figure 3

Figure 5. View inside the crawlspace showing no barriers against heat, air, or moisture vapor transfer between exterior or occupied spaces

Figure 6. Sump in crawlspace with a significant amount of bulk water

Figure 7. Plumbing leaks occurring from open pipe Figure 8. Location below plumbing leak in Figure 7 where moisture has accumulated

Figure 9. Corrosion of fasteners

Figure 10. Corrosion of pipes

Figure 11. Corrosion visible on active plumbing. Figure 12. Foundation wall with what appeared to be microbial growth previously identified by an industrial hygienist

Figure 13. Post in crawlspace near an alcove wall that was significantly deteriorated

Figure 14. Crawlspace walls with paint peeling and bubbling from moisture intrusion and high humidity

Figure 15. Unpainted wood sheathing showed degradation and what appeared to be microbial as compared to painted wood sheathing that appeared to be exhibit fewer issues

Figure 16. Wood ceiling of crawlspace showed degradation, corroded fasteners, and pipes

Figure 17. Location showing evidence of consistent and significant bulk water intrusion

Figure 18. Image showing same location as Figure 17 after a recent rain storm and increased bulk water was observed

Figure 19. Alcove in elbow of the building where moisture appeared to accumulate from both roof and site drainage

Figure 20. Standing water in alcove that showed evidence of draining into the crawlspace and corresponded to the location of water intrusion and structural degradation in Figures 13, 17, and 18.

Figure 21. Existing active ventilation system Figure 22. Example of foundation block out filled with insulation and evidence of cracking in foundation walls

Figure 23. Noted crack in foundation walls Figure 24. Evidence of pest intrusion into the crawlspace

Figure 25. Pipe penetration into first floor with no air or water tight seal

Figure 26. Fire riser penetrating the first floor with no air or water tight seal

3.2 Above Grade Walls

MH reviewed the overall conditions of the above grade, exterior walls and two invasive openings to understand conditions inside the walls. Specific findings were as follows:

1. The majority of exterior shingles appeared to be in serviceable condition.

2. MH noted through a limited invasive investigation that the weather resistive barrier

(WRB) installed on the building appeared to be Tyvek. MH understood from these openings that the Tyvek was installed as a water drainage plane but was not properly detailed at penetrations, fenestrations, and openings. Removing a section of an exterior window sill confirmed that no membrane had wrapped into the opening or provided an air or water seal to the window. Daylight was observed around penetrations through attic walls indicating penetrations were unsealed in that location. MH understands that leaks at penetrations, fenestrations and openings are widespread throughout the building contributing to material degradation and microbial growth. It was noted that the

WRB was not sealed to the foundation which was contributing to moisture intrusion and opportunities for pest intrusion.

3. The condition of the exterior sheathing was observed at the interior invasive opening and in the crawlspace. It is a diagonally applied soft wood lath that appeared to be in serviceable condition.

4. The interior insulation was noted to be a kraft paper-faced fiberglass batt that was degraded and contaminated with what appeared to be dirt and dust from air leakage.

The batt did not fill the stud cavity resulting in discontinuous insulation and vapor retarder which significantly reduces the effectiveness of controlling heat and moisture.

5. The interior drywall was observed only in public spaces and MH noted evidence of deterioration in two locations. The project team reported previous significant degradation of drywall and microbial growth that had been remediated.

6. MH observed the most prominent settling of walls and windows in the common room, but noted further evidence of structural settling that could be impacting other walls.

7. It appeared that exterior stairways were free standing and did not penetrate the building walls.

Figure 27. West corner of the building showing overall condition of the building exterior

Figure 28. Southwest elevation showing overall condition of the building exterior

Figure 29. Invasive opening around window under northeast porch – note staining on exposed shingle from water draining off window sill

Figure 30. Tyvek noted to be installed to the walls but not adequately wrapped into the window opening to provide an air or water tight seal

Figure 31. Exterior wall penetration with no visible seal

Figure 32. Diagonal lath sheathing visible in the crawlspace

Figure 33. Overall view of window where invasive opening was cut

Figure 34. Invasive opening around jamb and sill of interior window

Figure 35. Insulation located in stud that was degraded and contaminated with what appeared to be dirt and dust

Figure 36. Insulation that did not fill the cavity

Figure 37. Cavity side of drywall showing evidence of microbial growth and deterioration

Figure 38. Exterior staircase at the southeast elevation that did not appear to penetrate the enclosure

3.3 Attic

MH reviewed the overall conditions of the attic and roof and specific findings were as follows:

1. The existing design of the attic and roof assemblies was neither a completely vented nor non-vented system. The current system would be expected to have significant issues, but there were significant air flow pathways provided at the roof to wall and wall penetration interfaces. This air flow appeared to have effectively provided venting for the attic and therefore prevented moisture vapor build up and condensation. Additionally, the building is unoccupied during the winter months so there is likely a limited moisture vapor source during that increased risk period except for what may be coming from the crawlspace.

2. The roof was not insulated. There was intermittent insulation on the top of the second floor ceiling that was installed incorrectly with the kraft paper-faced side on the top/cold side.

3. A vapor retarder was noted in minimal areas on top of the second floor, drywall ceiling but was not installed over the majority of the attic.

4. Evidence of a significance pest issue was noted and is likely related to the significant discontinuities in the enclosure providing an access opportunity.

Figure 39. Infrared image showing thermal bridging across the attic walls indicating the attic is hot compared to the rest of the building

Figure 40. Corresponding visible light image to Figure

Figure 41. Insulation installed intermittently in the attic Figure 42. Area with no insulation or vapor barrier and wall penetrations with visible daylight

Figure 43.Vapor barrier minimally installed in the attic Figure 44. Overall view of the attic

3.4 Roof

MH reviewed the overall conditions of the attic and roof and specific findings were as follows.

1. MH understands that the low sloped portion of the roof was recently replaced with a temporary system over the top of the original roof and there was no apparent evidence of recent roof leaks. The roof membrane was EPDM membrane that had been installed fairly well for the most part. Some detailing of the membrane was noted to be improper and ponding was an issue in numerous locations.

2. The membrane turned down over the top of the mansard roof with a termination bar which should provide reasonable water shedding performance but may not provide adequate protection from ice dams and wind driven rain.

3. The roof membrane was noted to be mechanically fastened with numerous fastener heads standing proud which presents a risk of puncture from foot traffic and ice buildup.

4. The mansard roof was noted to have surpassed its service life and was in need of replacement. The shingles had surpassed their usable life and were in need of removal and replacement. Daylight could be seen from underneath the roof in several locations.

Figure 45. Roof over building addition Figure 46. Roof over main building

Figure 47. Inadequate detailing of roof membrane Figure 48. Ponding occurring on roof surface

Figure 49. Termination bar used at low slope edge and shingles in poor condition on the mansard roof

Figure 50. Daylight visible under the mansard roof

3.5 Porches and Awnings

MH reviewed exterior porches on the northeast and southwest elevations for their integrity and interface with the building. Specific findings were as follows:

1. The northeast porch was noted to have significant structural degradation of materials that may warrant complete removal and replacement. It appeared that the issues being experienced in the crawlspace were a contributing factor to the significance of the issue.

2. It was noted that the northeast awning appeared to have the same temporary EDPM roofing membrane as the low slope roof of the main building.

Figure 51. Southwest porch Figure 52. Northeast porch

Figure 53. Northeast porch roof at wall interface with what appeared to be EDPM membrane

Figure 54. Evidence of northeast porch stair settling and previous repairs to mitigate

Figure 55. Structural degradation of the northeast porch including the floor sloping toward the building

Figure 56. Structural degradation of northeast porch

Figure 57. Crawlspace access beneath the northeast porch

Figure 58. Crawlspace beneath the porch and connection to the main building crawlspace

3.6 Hygrothermal Data Loggers

MH placed a total of nine hygrothermal data loggers on the exterior of the building, inside the crawlspace, and in the occupied spaces. The data loggers recorded time, ambient temperature, and relative humidity for a two week period. MH analyzed the data to better understand the condition of the each space as well as relationships that were occurring between spaces.

Appendix 1 includes the floor plans of Laurel Dormitory taken from A&E’s Historic Structures

Report Draft with the locations of the data loggers labeled and data graphs corresponding to the specific findings below.

1. Daily maximum and minimum temperatures corresponded to opposite maximum and minimums in relative humidity which is a function of the temperature. Maximum temperatures occurred when the late afternoon sun was facing the elevation where the exterior data logger was placed.

2. The exterior data logger recorded an elevated relative humidity from precipitation that occurred on site and was confirmed by past weather data. The elevated relative humidity also occurred in the crawlspace and occupied spaces. Changes in temperature and relative humidity of the exterior environment correspond to similar changes in the interior of the building which suggests that the existing enclosure does not provide adequate separation from exterior conditions.

3. Five of the data loggers were placed around the crawlspace and each had different average temperature and relative humidity readings confirming the belief that hygrothermal conditions were not evenly distributed throughout the space. The majority of data from the crawlspace indicated that the temperature and relative humidity were consistently elevated compared to exterior conditions.

4. The data logger that was placed closest to the crawlspace active ventilation showed readings that were more similar to exterior conditions, with a wider range in temperature and relative humidity. This indicates that the existing ventilation has a mitigating effect on the hygrothermal conditions but it is not providing adequate ventilation to the entire crawlspace.

5. The relative humidity of the crawlspace was on average higher in the addition wing likely due its location outside the range of active ventilation. It is also approximately closer to the visible thermal feature toward the west.

6. The area with the highest temperature measured was toward the end of the main wing and corresponded to higher temperatures in the above lobby and second floor areas.

This location also corresponded to the previously recorded areas of damage and reported microbial growth on the IAQ field drawings. The lobby had a higher temperature than the second floor suggesting that the occupied space was being heated from the crawlspace below.

4 Discussion & Recommendations

Based on the review of the exterior and interior conditions of the Laurel Dorm crawlspace, MH has prepared recommendations for future actions and consolidated them into the list below.

4.1 Crawlspace

In summary, MH believes that the issues within the crawlspace and its interactions with the building above are due to the multiple sources of heat and moisture from below and above grade. The condition is further exacerbated by the lack of conditioning of the building in the winter. The current situation is untenable and is in need of remediation. The significant moisture load into the crawlspace is damaging the building in multiple ways including:

structural damage from wetting and drying cycles causing rot, corrosion of fasteners and plumbing, microbial growth (noted during our investigation and previously confirmed by an industrial hygenist) occurring at and above the floor assembly, and conditions conducive to condensation.

In order to address the issues, MH recommends a multifaceted approach to minimize the buildup of moisture in the space and provide a means of tempering the space to minimize risks.

1. In order to reduce the moisture ingress from grade, MH recommends the installation of a vapor retarder over the entire floor area of the crawlspace (recommend Stego

Wrap 20 mil vapor retarder with manufacturer tape, accessories, and terminations including a termination bar on the foundation wall). Ideally this should be installed over an even, continuous substrate. Ballast is recommended to be placed on top of the vapor retarder to protect and hold it in place, as well as protect it from damage during maintenance access. The vapor retarder should be terminated to the perimeter of the space as well as any penetrations in the floor. Provide locked access to this area to limit traffic over the exposed vapor retarder.

2. MH recommends removing the leaking and corroded plumbing components, replacing with new plumbing and coating to prevent future corrosion. Existing pipes deemed not to need replacement could also be cleaned and then coated with a protective product.

3. To address the moisture sources at the foundation wall, MH recommends two possible approaches. The best performing option is to install a waterproof membrane on the foundation walls as far down as possible with protective drain mat and drain rock at the depth of waterproofing. This option would require the foundation wall to be filled at all cracks, waterproofed, and covered with soil or cladding. MH recommends injecting cracks with a waterproof grout (De Neef) from

Grace Construction Products (GCP). The waterproofing system recommended is

GCP Bituthene 3000/4000, or GCP Procor Composite Waterproofing. An alternate approach would allow the foundation to be left exposed and would consist of filling all cracks in the foundation wall and installing a water-resistant coating on the exterior. The recommended water-resistant product would be GE SilShield Optic, which is a clear silicone, air and water barrier that is not completely invisible but adds only minimal visible luster. Because it is a barrier system, this would be a maintenance item that would need period review to ensure long-term performance.

4. MH recommends addition of free draining gravel and plumbed perimeter drainage for the building perimeter. The most effective drainage would be located at the bottom of foundation wall, or as far down as possible with the limitations on permitted excavation. Landscaping and grading should be designed to drain water away from the building.

5. MH recommends an additional drainage approach for the alcove at the inside corner of the building. After waterproofing the foundation walls to the extent and depth possible, MH recommends installing plastic (preferably the same vapor retarder recommended in item 1, above) and drainage at the depth of waterproofing with gravel and concrete drain “tub” over the top. This system would interface with the foundation wall perimeter drain. Bulk water that is present in the alcove appears to partially come from roof run off and MH recommends it be mitigated with gutters on the alcove roofs.

6. Liquid water intrusion should be further mitigated by providing an interface between the weather resistive barrier on the building walls and the foundation with a kickout flashing at the base of the shingle cladding. This will provide continuity and drainage of the wall system out and away from the foundation.

7. Given the apparent effectiveness of the current active ventilation in a limited area of the crawlspace, MH recommends a whole-crawlspace active ventilation system that engages with the existing block outs in the foundation but day lights at a level above where snow drifts build up in the winter. A secondary option would be to fill the passive block outs in the foundation, include them in the foundation wall waterproofing, and find another way to actively duct the space with a designed fresh air intake.

8. In order to compartmentalize the crawlspace and cut off its interaction with the building above, MH recommends installing a medium-density, closed cell spray foam insulation (recommend Icynene Proseal, Johns Manville Corebond, Bayseal

CCX, or similar) at a minimum thickness of 3" on the ceiling of crawlspace. This will be particularly important at penetrations through the floor. MH also recommends conducting WUFI analysis to determine the most effective and efficient spray foam depth.

9. MH recommends keeping the building above the crawlspace at or above 50 F in the winter (minimum). There may be opportunities to use existing geothermal heat sources beneath the building plumbed and pumped into the building radiator system to accomplish this. If this approach is not implemented, MH recommends an active ventilation system for the two floors above grade to keep the humidity levels and stagnant air to a minimum, which will further reduce risk of condensation and material degradation.

10. In order to confirm the effectiveness of any and all remedial measures taken, MH recommends permanent hygrothermal conditions monitoring in the crawlspace and the floors above to confirm the approaches are effective and to identify issues if and when they occur.

4.2 Above Grade Walls

MH believes that the deterioration and reported microbial growth issues occurring in the building walls are a combination of the crawlspace issues discussed previously, further moisture intrusion from the enclosure not being air or water tight, and the building remaining unconditioned through the winter.

In order to address these issues, there are multiple approaches with varying performance and risk that could be executed. The recommendations are tiered out starting with the best performing and lowest risk option. All approaches address the wall issues holistically and any partial implementation of these options may reduce the likelihood of some of the issues but would may not adequately address all of them.

Tier 1: For the best performance and lowest risk, MH recommends the following steps. Remove all shingles and trim cladding, remove the existing WRB, and remove all windows and doors.

Sheathing upgrades should be provided as necessary for structural integrity. MH recommends confirming with structural engineering that the existing sheathing provides adequate shear values and could be left in place with necessary repairs. Install a new, fully adhered, air and water barrier that is detailed into openings to permit interfacing with rebuilt or new fenestrations and other penetrations for mechanical, electrical, and plumbing (MEP). Reinstall windows and doors with continuous air and water tight detailing at all openings and to all adjacent assemblies. MH recommends replacing existing windows and doors, but we understand the historical significance of preserving the originals. Reinstall existing cladding if possible or as desired for aesthetics. From the interior, remove drywall and insulation. Clean as necessary to provide a suitable substrate for installation of spray foam at a minimum depth of three inches.

The spray foam will provide thermal, air, and vapor control as well as the necessary support for the new air and water barrier at the discontinuous diagonal lath sheathing. Replace the interior drywall to finish the new wall assembly. To prevent future degradation of the wall, the building should be conditioned through the winter or at a minimum be actively ventilated.

Tier 2: The next approach would permit the building to remain in operation during construction and should provide a similar performance to Tier 1 with minimal reduction in ideal performance due to the non-typical approach to installing the subcomponents. All exterior components would be removed as above with the addition of the sheathing. The spray foam would be installed from the exterior full depth into the stud cavities with careful attention to detail around the interfaces and transitions. This allows the interior drywall to remain in place. The spray foam should be shaved smooth to the outside. The assembly would then continue as above with the installation of continuous sheathing, a new air water barrier, and reinstallation of windows, doors, and cladding. It should be noted that this option may complicate the continuity of the air and vapor barrier system that would be installed.

Tier 3: This approach should provide cost savings but performance of the system will be reduced. Remove cladding and trim, existing WRB, windows, and doors. A cost saving alternative to spray foam would be to install a vapor retarder faced, mineral fiber insulation into the stud cavity from either the interior or exterior. The diagonal lath sheathing would be removed to provide continuous support to the adhered WRB and reinstalled over the insulation. Install a new, fully adhered air/water barrier and reinstall windows and doors as described in Tier 1. Note that this option may reduce the effectiveness of the air and vapor control due to the inherent discontinuities of paper-faced cavity insulation and the lack of intimate contact between the vapor control layer and the air barrier on the exterior.

Tier 4: The last approach would replace the wall system in kind with some improvements in performance over the existing condition but presents some constructability and performance risks. It would follow the same steps as Tier 3 but imploy a mechanically fastened, sheet applied

AWB that would not necessitate continuous sheathing. It should be noted that this type of AWB provides an opportunity for interior air to flow behind and inflate it when the building is pressurized. This presents a risk of condensation despite the AWB being permeable. The existing sheathing could then be left in place if it is structurally sound and if the vapor retarder faced mineral fiber insulation is installed from the interior.

4.3 Attic and Roof

Attic issues appeared to have a relatively minimal contribution to bulk water and moisture intrusion and resultant whole building issues, but should still be addressed. Our recommendations are tiered out starting with the best performing and lowest risk option.

Tier 1: MH recommends installing intentional venting in the attic designed per industry standard.

The attic should be vented with adequate pest occlusion screens regardless of the cold roof system chosen. Remove all existing insulation and vapor barrier products in the attic assembly, temporarily remove the existing catwalk, and install spray foam over the entire second floor ceiling surface. Ensure all wall penetrations and interfaces to the mansard roof and building walls are detailed to prevent air and water penetration and pest intrusion.

Tier 2: Another approach that may have reduced performance would be to recommend the same ventilation and pest protection as Tier 1, but use an alternative approach to insulation and vapor control. Remove all insulation and vapor barrier products then install new floor sheathing over the entire attic area and cut tightly to any second floor ceiling penetrations. Install a sheet poly or PVA primer continuously out to the exterior wall sheathing. Then provide Extruded

Polystyrene (XPS) insulation across the ceiling.

4.4 Roof

Roof issues appeared to have a relatively minimal contribution to bulk water and moisture intrusion and resultant whole building issues, but should still be addressed. Our recommendations are tiered out starting with the best performing and lowest risk option.

Tier 1: Remove both the temporary and original mansard and low slope roof assemblies. MH recommends the mansard roof be resheathed as necessary and then covered with fully adhered

GCP ice and water shield (IWS) underlayment. If any copper flashing will be used, GCP Ultra underlayment must be installed. MH understands the historic nature of the structure may require the installation of cedar shakes as opposed to longer lasting composite shakes. Cedar shakes are workable with a proper coating and the understanding that the life span may be limited. Two layers of IWS could be installed if cedar shakes are used to prolong the life of the roof. If a

Class A fire roof is desired, MH recommends an additional layer of underlayment with fire resistive qualities.

The new underlayment on the mansard roof should transition up onto the low slope roof area to permit a water tight interface with a new roof membrane (which would lap down onto the top of the mansard roof transition). MH recommends that the low slope roof area be re-sloped to provide positive drainage either out onto the mansard roof or to plumbed roof drains designed and provided for the roof area. Draining the large low slope roof area to heat traced, plumbed drains may reduce the amount of water and ice on the mansard roof which may prolong the life span. For the low slope roof area MH recommends a two ply SBS modified bitumen roof membrane manufactured by Soprema or Siplast.

Tier 2: A lower cost approach would follow all the same recommends as Tier 1 but using a fully adhered, single ply, PVC roofing membrane for the low slope roof section. Note that this system would not be as resilient when compared to a two ply SBS system.

4.5 Porches and Awnings

MH recommends that each porch be stripped, reroofed, and integrated with the new AWB and cladding systems on the building. There are a variety of options for re-roofing the awnings and the desired aesthetic may drive recommendations for the performance aspects including but not limited to standing seam metal roofing, single ply membrane, or shingles. MH recommends the crawlspace beneath the porch be either closed and cut off from the main crawlspace and made fully open to the exterior or fully incorporated into the enclosed, improved crawlspace as outlined above.

Please let us know if there are any questions or wish for further discussion.

Thank you, Kelly Sabrowsky Jack Pearson, CBST

Building Science Consultant Principal, Building Science Consultant

Morrison Hershfield - Minneapolis Morrison Hershfield - Mountain

U.S. Buildings Consultation Group U.S. Buildings Consultation Group

5 Appendix

5.1 Laurel Dormitory Floor Plans

Figure 59. Crawlspace plan with data logger label and placement

Figure 60. First floor plan with data logger label and placement

Figure 61. Second floor plan with data logger label and placement

5.2 Hygrothermal Data Graphs

Figure 62. Relative humidity at exterior, interior, and various crawlspace locations (that increased with exterior precipitation)

Figure 63. Temperature for exterior and all crawlspace data loggers showing crawlspace temperature is consistent except near the active ventilation

Figure 64. Temperature and relative humidity in the crawlspace near the active ventilation compared to exterior conditions

Figure 65. Relative humidity in the addition wing recorded to be higher than other locations in the crawl space

Figure 66. Temperature of hottest recorded crawlspace areas compared to interior spaces