To insulate or not?

[Meadowbend99]

Small commercial project designed to look like a house on piers (trying to match another existing structure), however the foundation is a continuous grade beam on piers 2' deep with several interior beams all the way around with no penetrations. There is a wood flooring system sitting on top with less than 6" between the bottom of joists. It has been built without insulation. An energy inspector was checking insulation and did not know if it should be insulated or not. We are in zone 2 and not required to insulate slabs. There is confusion on how to classify the foundation for insulation purposes as it sits so close to the ground and is fully enclosed, but it has a wood flooring system. Since it is already built it would be pretty dramatic to try to add insulation now. Would vents to the underside help or cause issues?

 

[RLGA]

Zone 2 requires R-30 in framed floors (2018 IECC, Table C402.1.3) or a U-factor of 0.107 (Table C402.1.4). This is concealed space (like an attic) that should be ventilated per Section 1202.4 (2018 IBC).

 

[steveray]

How did a commercial building get built without plans detailing required insulation?


[A] 107.2.4 Exterior wall envelope. Construction documents for all buildings shall describe the exterior wall envelope in sufficient detail to determine compliance with this code.

C103.2 Information on construction documents. Construction documents shall be drawn to scale upon suitable material. Electronic media documents are permitted to be submitted where approved by the code official. Construction documents shall be of sufficient clarity to indicate the location, nature and extent of the work proposed, and show in sufficient detail pertinent data and features of the building, systems and equipment as herein governed. Details shall include, but are not limited to, the following as applicable: 1. Insulation materials and their R-values.

 

[Paul Sweet]

What code was it built under?

 

[Meadowbend99]

2015 IBC and 2015 IECC