Installing New Crawlspace Access

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), and

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

Select materials that:

adequately support applied load and are permanent air barriers,

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

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

pest-resistant materials that are rated for ground contact anywhere they are in contact with the exterior foundation walls, piers, or bare earth

Install steel wool or other pest-proof material as infill in gaps greater than 1/4" before sealing

Remove any material from the sealing area that will prevent full adhesion of the selected sealant

Access openings through the floor will be a minimum of 18" by 24" or as constrained by existing framing members

Openings through a perimeter wall will be not less than 16" by 24" or as constrained by existing framing members

When any portion of the through-wall access is below grade, an area way not less than 16" by 24" will be provided

Under-floor spaces containing appliances will be provided with an unobstructed access large enough to remove the largest appliance but not less than 30" high and 22" wide and no more than 20 feet away from the appliance measured along the center line of the passageway from the opening to the appliance

A level service space at least 30" deep and 30" wide will be present at the front or service side of the appliance

If the depth of the passageway or the service space exceeds 12" below the adjoining grade, the walls of the passageway will be lined with concrete or masonry extending 4" above the adjoining grade in accordance with Chapter 4 IRC

Apply a continuous seal at all seams, cracks, joints, penetrations, and connections of access framing while applying sufficient pressure to push sealant into any gaps or cracks and contact any backing or infill material required

Install weather stripping, gaskets, or equivalent to exterior access doors/hatches

Install a latch, clasp, handle or equivalent that securely fastens access door/hatch closed and is designed for an optional lock installation