Closed Crawlspace - Non-Foam Insulation

Detail ID
4.0402.1
Topic
Conditioned Subspaces
SubTopic
Walls
Desired Outcome

Continuous, contiguous, pest and moisture resistant, and safe thermal boundary that prevents air movement @ 50 Pascals

SF Single Family Site-Built Housing
MH Manufactured Housing
MF Multifamily Housing

Specifications

  • SF
  • MF
Specification Objective

Verify that installation area is free of:

active water leaks, fuel leaks (i.e., gas, oil, propane), and pest intrusions

energized or undammed knob and tube wiring

uncovered electrical junctions

improperly terminated devices (ventilation fans, dryers, plumbing stacks, condensate lines, combustion appliance flues/chimneys, etc.)

unshielded high-temperature devices (non-IC rated recessed lights, chimneys, flues, vents, etc.) unless they are zero clearance devices

insulation escape openings

Verify that installation area:

is intact, able to support insulation weight, and air sealed

has a sealed class I vapor retarder installed over all bare earth

has all bulk sources of moisture directed away from the subspace walls (i.e. gutters, flashing, grading, drainage)

Ensure space can be safely insulated

  • SF
  • MF
Specification Objective

Select insulation that:

has a flame spread/smoke development index of 25/450 or less when tested in accordance with ASTM E 84 or UL 723

is, or include a facing that is, a class II vapor retarder

is non-absorbent

Select fire safe and moisture resistant materials

  • SF
  • MF
Specification Objective

Select sealants that:

are compatible with their intended surfaces

allow for differential expansion and contraction between dissimilar materials

meet the requirements of the applicable fire safety code (e.g., thermal or ignition barriers)

are low volatile organic compound (VOC) sealants for use inside the pressure boundary that meet independent testing and verification protocols

Select safe and effective sealants

  • SF
  • MF
Specification Objective

Ensure wall vapor retarder will lap underneath the ground vapor retarder connection to the foundation wall

Remove any incomplete or unsealed vapor barrier from the foundation wall

Keep bulk water below vapor retarder and prevent condensation

  • SF
  • MF
Specification Objective

Install insulation to prescribed R-value in full contact with the foundation wall from ceiling to floor with vapor retarder facing the conditioned space

Contiguous and continuous thermal barrier

  • SF
  • MF
Specification Objective

Mechanically attach insulation to foundation wall

Insulation remains in place

  • SF
  • MF
Specification Objective

Seal all seams, joints, connections, etc. of insulation and vapor retarder layer with compatible sealant (i.e., tape, mastic, adhesive)

Seal ground vapor retarder to the insulation vapor retarder with the foundation vapor retarder lapped under the ground vapor retarder

Airtight insulation

  • SF
  • MF
Specification Objective

If termite pressure exists, maintain a 3" inspection gap from the top of the insulation to the bottom of any wood

Allow for termite detection

  • SF
  • MF
Specification Objective

Post a dated receipt signed by the installer that minimally includes: Installed insulation type, coverage area, installed thickness, and installed R-value

Comply with 16 CFR 460.17 and document contract compliance

View Sub-Topic:
Walls