4.1301.10 Above-Grade Exposed Floor, Joisted Assemblies

Topic: 
Floors
Subtopic: 
Accessible Floors
Desired Outcome: 
Maintain a consistent, protected, uniform thermal boundary Thermal boundary The separation between the interior and exterior environments of a building that slows heat flow between conditioned and unconditioned space to prescribed R-value
For supporting material, see Referenced Standards.
TitleSpecification(s)Objective(s)
4.1301.10a
Pre-inspection

Conduct pre-inspection in accordance with SWS 2.0100.4 Work Area Inspection and Stabilization

Gaps, cracks, and holes in fire separations located within the work area will be visually identified and incorporated into air sealing work scope, including those that span two conditioned or unconditioned spaces

Where drawings are available that identify specific fire-resistance ratings (i.e., 1 hour, 2 hour), materials and methods will be employed to preserve or restore such rating

Where drawings are unavailable or do not identify specific fire-resistance ratings, the fire-resistance rating of the assembly may be inferred from the current construction (i.e., single 5/8 sheetrock, concrete masonry unit), and materials and methods employed will be consistent with restoring or preserving such inferred fire-resistance rating

Repairs necessary to stabilize work areas and protect or preserve integrity of energy improvement will be completed before subject work begins

Repair moisture-related issues

Provide a safe and stable work environment

4.1301.10b
Preparation

Health and safety concerns will be addressed for occupants, workers, and repair materials in accordance with OSHA OSHA U.S. Occupational Safety and Health Administration, www.osha.gov standards ( OSHA OSHA U.S. Occupational Safety and Health Administration, www.osha.gov 1926, 1910)

Prepare and isolate the area in accordance with health and safety standards for the application and materials (e.g., extreme temperatures, lead, asbestos, carbon monoxide)

Work lighting, work platform, and adequate ventilation will be provided

Provide a safe working environment

Provide a safe indoor environmental quality working environment

Provide effective repair access

4.1301.10c
Subfloor preparation

Sealing between conditioned space and unconditioned space will be completed before insulating

Ensure airtight envelope Envelope The separation between the interior and exterior environments of a building that includes a combination of air and thermal barrier

Prevent leakage

4.1301.10d
Installation

Insulation will be installed to at least prescribed R-value

Insulation will be installed in contact with subfloor without gaps, voids, compressions, misalignments, or wind intrusions

If vapor retarders are used, they will be installed consistent with local climate/code requirements

Prevent potential fire chases

Provide effective R-value

Prevent excessive vapor migration into the floor assembly and/or conditioned space

4.1301.10e
Installation of batts or dense pack Dense pack The process of installing loose-fill insulation to reduce air flow and perform to a stated R-value

Insulation will completely fill the cavity space within the joists or trusses

Minimize sagging, gaps, and voids

4.1301.10f
Installation of rigid insulation

Rigid insulation will be mechanically fastened to the bottom of the subfloor or at the bottom of the joists or trusses

If attached at the bottom of the joists or trusses, rigid insulation will be attached at the exterior perimeter/band

Insulation will be installed either as in-fill or at the bottom of the joists. Where rigid insulation is installed between joists, the perimeter of each joist bay will be air sealed with appropriate sealants to prevent air bypasses around rigid insulation materials

Rigid foam plastics used as insulation will incorporate a thermal and ignition barrier Ignition barrier Any layer of material that protects another from catching fire due to heat or spark , as required by the building code

A continuous air barrier Air barrier The separation between the interior and exterior environments of a building that slows air flow to the point that no smoke movement is visible at 50 pascals of pressure difference across the boundary will be installed below the insulation and to the exterior

Minimize convective loops

Prevent freezing of plumbing pipes

Ensure air barrier Air barrier The separation between the interior and exterior environments of a building that slows air flow to the point that no smoke movement is visible at 50 pascals of pressure difference across the boundary is aligned with the insulation

4.130.10g
Installation of spray polyurethane foam ( SPF SPF Spray polyurethane foam )

SPF SPF Spray polyurethane foam will be applied to bottom side of subfloor between floor joists and all rim/band joists

Spray applied foam products will incorporate a thermal and ignition barrier Ignition barrier Any layer of material that protects another from catching fire due to heat or spark as required by the building code

Insulation will be installed by foam installers

Minimize convective loops

4.1301.10h
Installation, if mechanicals in joisted assemblies (applies to all insulation types)

All plumbing or mechanical ductwork will be enclosed within the insulated space and will have sufficient insulation on the exterior side

Prevent freezing of plumbing pipes

4.1301.10i
Secure batts

Batts will be secured with physical fasteners

Ensure insulation remains in contact with subfloor

4.1301.10j
Rigid protective barrier

A continuous rigid barrier, suitable to withstand weather, moisture, and pest contact, and with a fire-resistance rating equal to the resistance rating of the original floor assembly will be mechanically fastened to underside of floor assembly

Protect insulation

4.1301.10k
Property manager education
A dated receipt signed by the installer will be provided that includes:
  • Insulation type
  • Coverage area
  • R-value
  • Installed thickness and settled thickness (settled thickness required for loose-fill only)
  • Number of bags installed in accordance with manufacturer specifications (for loose-fill only)

Document job completion to contract specifications

Confirm amount of insulation installed

Comply with 16 CFR 460.17