Review of the commercial rehabilitation project for the Hubbard House Carriage House improvements. 

ISG on behalf of the City of Mankato. 

The applicant is requesting the review of needed venting to the outside of the structure to accommodate the new floor installation. 

ISG was engaged by Claudia Hicks on behalf of the City of Mankato to complete a visual structural inspection and recommendation on the site located at 606 S Broad Street, Mankato, MN 56001.

The evaluation was prompted due to ice damns forming at the eaves of the roof throughout winter. The city proposed isolating the floor of the attic space and adding attic ventilation to reduce the amount of snow melt on the roof.

It is recommended by ISG that, in order to add insulation to the attic floor and ventilate the roof, the City of Mankato shall reduce the attic floor live load to 20 psf.

Next Steps: 

Based on report findings and the existing structural accommodations, next steps would include:

1. Confirm ability to reduce overall storage in the attic to allow for added floor construction and remain within the allowed live load.
2.  Remove all items from the attic to allow for the installation of 2x6 wood framing on top of the current floor and infill space between framing with insulation. Install a vapor barrier below the insulation and new wood flooring on top of the framing over the top of the insulation.
3.  Add a door and enclosure at the top of the stairs to fully enclose and separate the attic from the space below.
4. Remove any through-floor venting and seal any penetrations between floors.
5. Remove any existing cavity insulation and vapor barriers from the roof framing.

This scope of work will reduce the conditioned space to only the first floor. The attic will not be conditioned and will be the same temperature and humidity as the exterior environment. Any storage that may take place in the attic after this scope should be able to withstand yearly temperature and humidity swings.