A better
foundation for comfort.

01 / CONTROL THE BOUNDARY

Less ground moisture.
A more controlled space.

A continuous sealed ground membrane reduces water vapor entering from the soil. Perimeter air sealing and insulation can reduce unwanted outdoor-air entry and heat loss. With the right water management and humidity plan, encapsulation can help protect floor framing and improve comfort above.

It is not a cure for active groundwater, leaking pipes, poor drainage, structural damage, or every indoor-air concern. Those conditions need their own correction. Results depend on the starting conditions and the completed system.

02 / BUILD A COMPLETE SCOPE

Six pieces to
talk through first.

1. Bulk water: drainage, leaks, standing water, and any sump or repair needs.
2. Ground vapor control: a durable continuous membrane, sealed seams and penetrations, and sealed perimeter attachment.
3. Thermal boundary: wall and rim insulation suited to the jurisdiction, assembly, and home type.
4. Air and humidity control: the required ventilation or conditioning approach, plus any supplemental dehumidification.
5. Fire protection: the foam’s required barrier or the exact tested exception for this use.
6. Access and ongoing care: service access, piers, drainage equipment, inspection needs, and a plan to monitor moisture.

03 / MICHIGAN RESIDENTIAL BASELINE

Yes, an unvented crawlspace
has a code pathway.

The adopted 2015 residential framework’s R408.3 pathway includes a continuous Class I vapor retarder over exposed soil. Seams overlap at least 6 inches and are sealed or taped; edges extend at least 6 inches up the stem wall and are attached and sealed.

The principal air-control options are continuous mechanical exhaust or a conditioned-air supply, each at 1 cfm per 50 square feet of crawlspace floor area, with the specified pathway to the common area and insulated perimeter walls. Existing-structure plenum arrangements have a separate listed path. The selected system also has to work with combustion appliances and the foam’s fire-protection conditions.

The 2015 text does not list a stand-alone dehumidifier as a substitute for these prescribed options. A dehumidifier may support humidity control; using a different compliance method requires approval of that alternative.

2015 IRC R408.3 and Michigan’s current code status. Confirm the applicable state amendments, permit requirements, and approved design with the building department.

04 / WISCONSIN IS A SEPARATE CHECK

Use the Wisconsin UDC,
not a copied Michigan checklist.

SPS 322.34 requires a continuous vapor retarder over exposed earth, with 6-inch sealed or taped overlaps and edges extending at least 6 inches up the foundation, attached and sealed to the wall or insulation. Remove decayable organic material first. Wall insulation is permanently fastened and covers the full wall height; frost protection can also matter.

Wisconsin’s UDC is not the Michigan-adopted IRC. Do not assume the Michigan 1-cfm-per-50-square-feet pathway is the Wisconsin rule. Confirm the moisture-control, mechanical, and foam-protection details for the actual project with its inspector.

Wisconsin’s foam-protection rule and the space’s connection to living areas also matter. We review any connection to living areas, heat sources, storage use, and the product’s approved assembly. The current rule, actual layout, product approval, and inspector review determine the required protection.

SPS 322.34 and 322.38; SPS 321.11. See Wisconsin county and insulation guidance.

05 / USE & AIR CONNECTIONS CHANGE THE ANSWER

When does the foam
need a covering?

Start with the required thermal barrier. A qualifying limited-access crawlspace may use a permitted ignition barrier or tested alternative, but the exception has conditions. Storage and regular occupancy change the analysis; so can open connections, air circulation to other parts of the house, appliances, and the access arrangement.

Heatlok HFO Pro’s tested no-prescriptive-ignition-barrier route has restrictions that include utility-service-only access, no storage, and no circulation of the crawlspace’s air to other building areas. Do not combine that exception automatically with a conditioned crawlspace that shares house air. A protective covering or a different approved assembly may be needed.

A stairway is a reason to examine access and use—not a universal rule by itself. Heat-producing equipment also requires a review of clearances and combustion air. The final fire-protection scope should be settled before installation, not left to guesswork after the foam is in place.

Source: HFO Pro ER-0565, §4.5. This product-specific route does not replace Wisconsin’s UDC or jurisdictional approval.