Basements - With Groundwater Leakage

Detail ID
4.0402.5
Topic
Conditioned Subspaces
SubTopic
Walls
Desired Outcome

Continuous, contiguous, 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 and is not water absorbent

Fire safe and hydrophobic insulation selected

  • SF
  • MF
Specification Objective

Install a continuous drainage plane at the interior surface of the exterior basement wall or leave an airspace of at least 1/2" between insulated wall assembly and foundation wall from the top of the wall to a drainage field at the bottom of the wall or sub-slab that drains to outdoors

If foundation is rough (i.e., rubble, stone), install a waterproof membrane to which insulation will adhere

Remove bulk moisture from interior surface of basement wall

  • SF
  • MF
Specification Objective

Install insulation to prescribed R-value in a continuous boundary around the entire perimeter of foundation wall from top of band joist to floor, in contact with any waterproof membrane that exists at the foundation wall

Contiguous and continuous thermal barrier

  • 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 and if subslab drainage is installed, termite treatment will be performed

Allow for termite detection

  • SF
  • MF
Specification Objective

Attach rigid or batt insulation with mechanical fasteners or other means that has a minimum service life of 20 years

Insulation remains in place

  • SF
  • MF
Specification Objective

Install a continuous air barrier between the foundation and the interior of the basement that spans from the slab to the subfloor above

Seal all seams, joints, connections, etc. of insulation on the conditioned side or create an airtight wall assembly on the conditioned side of the insulation

Continuous air barrier on heated side of assembly

  • SF
  • MF
Specification Objective

Separate all foam products from living space with a thermal barrier material (e.g., 1/2" gypsum wallboard) as specified by applicable building code

If space is used only for the service of utilities, foam will be separated from the space using a suitable ignition barrier covering or coating according to manufacturer's specifications

If space is used for storage or occupancy, spray foam will be separated from the space using a thermal barrier material (e.g., 1/2" gypsum wallboard) as specified by applicable building code and manufacturer specifications

If code requirements are unclear, consult local code officials for clarification

Minimize ignition and combustion potential

  • SF
  • MF
Specification Objective

Do not install a vapor retarder layer on either side of the wall (e.g., vinyl wallpaper, polyethylene, latex paint)

Allow wall to dry to the interior

  • 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