02-385-110 Me. Code R. § 2-13

Current through 2024-51, December 18, 2024

Section 385-110-2-13 - Radon Mitigation Preparation Standard

1. Purpose and Scope

The purpose of this standard is to provide a reasonable code for manufacturer-installed vent piping and electrical supply boxes within the envelope of a state-certified modular home to facilitate future, on site completion of the radon mitigation system should such a system be required either by code or by the consumer. This standard is based on Appendix F: Radon Control Methods of the IRC, a nationally recognized code, that will apply to all state-certified modular homes that are installed in Maine. This standard sets forth design and construction requirements relating to preparation for radon mitigation in state-certified modular homes.

2. Compliance; Limited Waiver of Compliance

State-certified modular homes must comply with the provisions of this Section. The executive director may waive compliance with the radon standard contained in subsection 4 in the limited circumstances described in subsection 4(I).

3. Materials and Equipment

Materials and equipment must be identified in a manner that will allow a determination of their compliance with the provisions of this subsection. (2009 IRC, N1101.3) Materials and equipment used to conform to the applicable provisions of this chapter must be installed in accordance with the manufacturer's installation instructions.

4. Radon Standard

A. Entry routes

Potential radon entry routes such as openings around bathtubs, showers, water closets, pipes, wires or other objects that penetrate the floor assemblies must be filled with a suitable sealant applied in accordance with the manufacturer's recommendations. (2009 IRC, AF103.4.1)

B. Vent pipe

The manufacturer must install a 3-inch-minimum diameter vent pipe up through the building floors at least 2 feet into the attic space and capped below the roof. The vent pipe must be installed such that the pipe can be extended by others at a later date and located at least 12 inches above the roof in a location at least 10 feet away from any window or other opening into the conditioned spaces of the building that is less than 2 feet below the exhaust point and 10 feet from any window or other opening in adjoining or adjacent buildings. (2009 IRC, AF103.5.3 and AF103.6.1)

C. Vent pipe drainage

All components of the 3-inch-minimum diameter vent pipe installed by the manufacturer up through the building floors and capped below the roof must provide for positive drainage. (2009 IRC, AF103.7)

D. Vent pipe accessibility

Radon vent pipes must be accessible for future fan installation through an attic or other area outside the habitable space. (2009 IRC, AF103.8) Any accessible space reserved for the radon fan must occupy an imaginary cylinder, standing on end, which is 24 inches or more in diameter, centered on the axis of the vent pipe, and extending a minimum vertical distance of 3 feet.

Exception:The radon vent pipe need not be accessible in an attic space where an approved roof-top electrical supply is provided for future use (2009 IRC, AF103.8), and where it is possible to mount the future fan above the roof.

E. Vent pipe identification

All exposed and visible interior radon vent pipes must be identified with at least one label on each floor and in accessible attics. The label shall read: "Vent Piping for Future Radon Reduction System." (2009 IRC, AF103.9)

F. Combination foundations

For homes designed to be placed on combination basement/crawl space foundations, the manufacturer may, but is not required to, install separate 3-inch-minimum diameter vent pipes for each type of foundation area up through the building floors and capped below the roof. (2009 IRC, AF103.10)

G. Power source

To provide for future installation of an active depressurization system, an electrical circuit terminated in an approved box must be installed by the manufacturer in the attic or other anticipated location of vent pipe fans. (2009 IRC, AF103.12) If the circuit is dedicated solely to vent pipe fans, the manufacturer must install in the living space of the home a visual indicator that the circuit is energized, or an alarm that the circuit is not energized. If the circuit is not dedicated solely to vent pipe fans, future installation of vent pipe fans must be taken into account when designing the circuit.

H. Testing

Vent pipesmust be tested at the manufacturing facility for tightness. Fully-assembled vent pipes must be field-tested by the dealer or installer unless the vent pipes were tested in a fully-assembled state at the manufacturing facility.

I. Waiver of Compliance With the Radon Standard

(1) A manufacturer may obtain a waiver of compliance with the radon standard contained in this subsection by demonstrating to the executive director of the board that the design or construction of a dwelling makes it infeasible, as set forth below, to install piping and/or electrical supply boxes within the envelope of a state-certified home to facilitate future, on site completion of the radon mitigation system should such a system be required by code or by the consumer. The waiver request must be made prior to acceptance of the plans by the manufacturer's board approved third-party inspection agency.

(2) In determining feasibility of compliance with the radon standard, the executive director shall consider as alternatives to a waiver the manufacturer's ability to achieve compliance through alternative construction techniques, use of different materials, or design change. The executive director may also consider other relevant factors, including cost of compliance, although cost of compliance alone is not a ground for obtaining a waiver. It is the intent of the board that waivers be sparingly granted.

(3) The executive director's denial of a waiver must be made in writing, must state the basis for the denial, and must inform the manufacturer of the time and manner in which an appeal to the board may be taken pursuant to Subchapter 6.

02-385 C.M.R. ch. 110, § 2-13