RECREATIONAL EAGLE CENTER METAL ROOF ASSESSMENT AND SOLUTION

Transcription

1 RECREATIONAL EAGLE CENTER METAL ROOF ASSESSMENT AND SOLUTION Recreational Eagle Center (00550) La Crosse, WI DSF Project No. 07H1E SEG Project No Prepared for Division of State Facilities 101 E. Wilson Street, 7 th Floor P.O. Box 7866 Madison, WI Prepared by Russell P. Mohns, P.E. Dan Dinjer Specialty Engineering Group, LLC 6214 Putnam Rd. Madison, WI May 2, 2008

2 Table of Contents Introduction 1 Existing Construction 2 Conclusions 6 Solution 6 Appendix Site Map

3 Introduction The Recreational Eagle Center (REC), UW-La Crosse building number 00550, was designed by SDS Architects. Market and Johnson was the buildings General Contractor. The Building was opened circa The purpose of this report is to assess the condition of the metal roof areas on the Recreational Eagle Center main complex and to provide a solution to correct any existing deficiencies associated with the metal roof system. Assessments of the flat roof areas, Child Care facility located to the east and the connecting link are not part of this assessment. The University has previously assigned an alpha code for the individual roof areas. This assessment will refer to the individual roof areas using this code. The aerial view shown below provides the alpha code associated with the individual roof areas. Roof Areas included in this assessment are G, I, K, M and N. Also included in this report are the effects that rain and drifting and sliding snow and/or ice have on adjacent roof areas and grade levels. The investigation included visual observations of the interior and exterior. Historical data was provided by the Owner through means of interviews. Building plans were available for review. L K F M J G N I H Aerial View of Recreational Eagle Center 1

4 Existing Construction and Conditions According to the original plans, the existing roof assemblies on all five (5) roof areas consist of the following components: Pre-formed, pre-finished standing seam roof panel. Panel seams consist of a separate prefinished metal snap cap having an integral gasket to provide the weather tight seal. Asphalt saturated underlayment felt Steel deck, structurally sloped at 3 inches per foot, spray on fireproofing on underside Vented attic space Perforated steel soffit along eaves provide ventilation intake; Exhaust ventilation on all areas except G and N is provided by gravity pod vents. It is assumed that exhaust ventilation of G is provided under the large sheet metal flashing at the top of the cone. This can not be verified without destructive testing. Fiberglass insulation Polyethylene vapor retarder Gypsum board Typical Eave Detail Original Drawings Typical Wall Detail Original Drawings View of Soffit Vent End View of Snap Cap with Gasket 2

5 K North Elevation Roof Area K Moisture intrusion into the aerobics room Roof Panel snap caps loose Fascia panel snap caps loose and missing Moisture run-off onto grade creates problems along foundation line Bent pipe penetration as the result of snow slides Snow slides block emergency exit doors N I South Elevation Roof Area I Roof Panel snap caps loose Fascia panel snap caps loose and missing Missing exhaust vents (assumed to be wind related damage) Snow build-up on the lower flat roof causes moisture intrusion along the flashing Roof Area N Roof Panel snap caps loose Fascia panel snap caps loose and missing Snow/ice slides at west access doors are a problem No thru-wall flashing or weep holes in masonry wall between windows. A thru-wall flashing and weep holes are present above the windows. 3

6 G M East Elevation West Elevation Roof Area G Roof Panel snap caps loose Fascia panel snap caps loose and missing No thru-wall flashing or weeps in masonry wall along stepped counter flashing Snow and ice slides onto lower flat roof areas builds-up against windows creating moisture intrusion of the wall and flat roof areas Roof Area M Roof Panel snap caps loose Fascia panel snap caps loose and missing Previous damage to exhaust vents Snow and ice slides off roof blocking access doors It was noted that the masonry wall sealant joints are deteriorated with adhesive and cohesive failures. Typical Photographs Typical View of Vented Attic Area Missing Snap Cap 4

7 Typical Missing Attic Vent Damaged Pipe Penetration From Snow Slide Improperly Installed Pipe Flashing No Thru-Wall Flashing or Weep Holes Above Stepped Counter Flashing Weep Holes and Thru-Wall Flashing Along Window Head No Weep Holes Above Roof Apron Flashing No Thru-Wall Flashing or Weep Holes Above Stepped Counter Flashing 5

8 Conclusion Moisture intrusion of the Roof Areas with metal panels is a result of deteriorated snap cap gaskets that provide the weather tight seal. In addition to the deteriorated gaskets, snow and ice lifts the snap caps and deform the panels not allowing the cap gaskets to provide a weather tight seal. Fiberglass insulation is assumed to be wet due to the amount of moisture intrusion. Deteriorated sealant joints and the lack of thru-wall flashings and weep holes do not appear to be causing moisture intrusion of the interior. Replacement of the roof panel system and the inclusion of a snow retention system will not substantially alleviate the build up of snow on lower flat roof areas. Replacement of the roof panel system will not alleviate the problems at grade level associated with water run-off. The inclusion of a gutter and downspout system was examined but, it was determined that the problems created by as well as the maintenance associated with a gutter drainage system would not be a long-term benefit. Solution The following solution is proposed for the existing metal roof portions of the Recreational Eagle Center The existing metal roof system on the five (5) individual areas should be replaced with a standing seam metal roof system that has a crimped type seam or cap. All areas should be replaced at the same time. Replacement of roof areas over an extended timeframe will result in roof panels not having the same color due to color variations between paint lots and weathering of the in place panels. Portions of the existing structural deck should be lifted and the existing fiberglass insulation and underlying gypsum board be observed with wet/deteriorated sections removed and replaced. A snow retention system should be installed along portions of the roof over egress and ingress locations and areas with lower roof areas Penetrations should be reinforced to resist sliding snow and ice Estimate of probable construction cost: Roof Area G 6500 SF X $ 30/SF = $195,000 Roof Area I 4700 SF X $ 20/SF = $ 94,000 Roof Area K 7300 SF X $ 20/SF = $146,000 Roof Area M 2700 SF X $ 30/SF = $ 81,000 Roof Area N 2500 SF X $ 20/SF = $ 50,000 Total $566,000 6

9 Additionally it is recommended that the following work be accomplished: An assessment of the masonry sealants and thru-wall flashings should be made to determine what additional work is required prior to the application of the new roof system. An assessment of the surrounding landscape should be made to determine if grading elevations can be changed and/or if drainage tile should be installed around the building perimeter to alleviate damage to the lower portion of the masonry walls A structural assessment should be made of the lower roof areas that experience snow accumulations to ensure that they are structurally capable of supporting the excess amounts of snow. 7

10 Appendix

11 Specialty Engineering Group LLC REC Metal Roof Assessment and Solution Site Map