Mississippi Flats

building type: A Minnesota Condominium Association

Location: St. Paul, MN

Project Team: Gittleman Construction & Maintenance (GCM) – Construction & Hvac Divisions

GITTLEMAN EXPERTISE: General Contractor // Project Management // HVAC Replacement


The Mississippi Flats Condominium Building is a five-story building that consists of 93 Units. The condominium experienced water intrusion behind the siding.  During the project planning, it was determined that replacing obsolete HVAC units in conjunction with the façade replacement would effectively save the Association an estimated $7,500 per unit versus replacing the units one at a time over the course of the next 5-7 years.


Original façade construction consisted of a combination of Hardie Panel siding and corrugated metal panels. During pre-project investigation it was determined that the weather barrier installation behind the siding was deficient and was resulting in localized water intrusion at the following locations:

  • Balcony/Deck Doors
  • Penetrations (such as exhausts and receptacles)
  • Mechanical louvers of SkyMark units (vertical heating and cooling equipment)
  • Horizontal mullions of vinyl windows (at mullion flashings)


The façade repairs consisted of:

  • Removal of the existing Hardie Panel siding and select metal panel siding to expose the existing weather barrier. The existing siding system was replaced with corrugated metal paneling.
  • Partial removal of the existing weather barrier to expose and repair exterior sheathing and framing damages.
  • Removal and replacement of residential patio doors. Installation of the new doors incorporated rough opening flashings and insulation.
  • Repairs to window flashings at mullions.
  • Replacement of exhaust hoods and select fireplace exhaust hoods.
  • Partial removal and reinstallation of deck boards as required to install weather barrier and flashings (Example: Recessed balcony locations with membrane roofing present.)
  • Removal and reinstallation of the French railing on the courtyard elevation to allow for framing repairs. Reinstallation of railings also incorporated ledger flashings.


Original construction also consisted of the installation of SkyMark vertical heating and cooling units. This type of mechanical heating/cooling system was present at 81 homes. During pre-project investigation it was determined that the original installation of the wall sleeve was deficient and allowed air and vapor bypass to occur. During cold temperatures, this condition was susceptible to allowing condensation to form on the housing of the mechanical equipment and within the mechanical closet of each unit.  It was also determined that SkyMark was no longer producing replacement and repair parts – so once a unit reached the end of its useful life (i.e. in 5-7 years) the unit would need to be fully replaced.  However, replacement units in the marketplace require a different wall opening size.  To replace respective HVAC units in the course of time after completion of the façade project, would require cutting new openings in the new façade and that endeavor would cost as much or more than the cost of the new HVAC unit itself.  In the final analysis the Association decided to replace the HVAC units in concurrent fashion with the façade replacement project.

The mechanical equipment replacement consisted of:

  • Removal and replacement of 81 SkyMark units. These units were replaced with Magic- pak vertical heating and cooling units.
  • Installation of the new mechanical louver required modification of the existing rough opening. Modification generally consisted of widening the opening by reinforcing the header (beam) and relocating the jamb post.
  • Repairs to furnace closets finishes (Example: Laminate flooring and drywall) where damages were present.