IAQ Implications of Maine’s Updated Building Code

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A builders and homeowners guide…

Contributed by Christine Crocker, executive director, Maine Indoor Air Quality Council

The changes made by the Maine State Legislature this year will impact two key areas of air quality in home construction: ventilation and radon. Here’s a quick summary of these provisions and what builders and homeowners should know.

1.The ASHRAE 62.2 Ventilation Standard and the ASTM Radon Standard are now mandatory for all new Maine homes.

Before the recent changes, application of the ventilation standard for minimum ventilation and the radon standard for “building radon out” of new homes were voluntary.

2. What is the ventilation standard and what does it cover?

The 62.2 Standard, “Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings” is published by the American Society of Heating, Refrigeration and Air Conditioning Engineers. It applies to single-family homes and multi-family structures of three stories or fewer above grade, including manufactured and modular homes.  Many of the standard’s core provisions are already common modern building practices today.

Core provisions of the standard:

  • Local exhaust of high pollutant areas: Kitchen — 100 cfm vented range hood, demand controlled; bathrooms (tub, shower, spa) — 50 cfm, demand controlled
  • Whole building ventilation for each dwelling unit achieved with a mechanical exhaust system, a supply system or combination of the two. The rate of ventilation must meet a minimum requirement, which is calculated using the square foot area of the dwelling and the number of bedrooms.
  • Minimize air movement from garages, crawlspaces, and attics to occupied spaces.
  • Instructions and labeling for ventilation devices.
  • Vented clothes dryers to the outdoors (except condensing dryers).
  • Adequate supply air to combustion appliances.
  • Sealed ventilation ductwork.
  • At least one installed carbon monoxide alarm in each dwelling unit.
  • Compliance with sound rating requirements for mechanical ventilation devices.

Until the Technical Codes Board updates Maine’s code, the 2013 version of the Standard is what will be applied in Maine. Downloadable and printed copies of the Standard can be purchased directly from ASHRAE Bookstore at www.ashrae.org.

3. What is the Radon Standard and What Does It Cover?

The E-1465 Radon Standard, Standard Practice for Radon Control Options for the Design and Construction of New Low-Rise Residential Buildings,” is published by the American Society of Testing & Materials.  This standard provides guidance for how to install both passive (without a fan) and active (with a fan) radon prevention system in a newly constructed home. The incorporation of this standard as a mandatory component of Maine’s code is huge for Maine homeowners: exposure to radon causes lung cancer, and one in three Maine homes is expected to have elevated levels.

Core provisions of the standard:

  • Proper materials (crushed rock, poly) for use under the slab
  • Proper placement of radon collection pipes under the slab
  • How to avoid practices that cause common system failures, such as when footings are poured on blasted rubble or when ground water control and radon control systems short circuit each other
  • Proper sealing of the pipe stub and any other foundation penetrations, such as sumps or utility pipes and water control pipes through footings
  • Placement and labeling of the radon vent stack from the pipe stub through the roof
  • Installation of a junction box and electrical preparation in the event the system needs to be activated (with a fan)
  • Radon in air test prior to occupancy
  • Activation (installation of a fan) of the system should the radon in air test determine the passive system isn’t reducing radon to acceptable levels.
  • A retest of the radon in air following system activation to ensure the system is reducing radon to acceptable levels.
  • Provide homeowner with documentation and operation instructions

Note:  Maine law allows contractors and homeowners to install the system and activate it at the point of new construction as long as the system was planned and designed prior to construction start. After completion, only homeowners themselves or contractors who are trained and registered by the Maine CDC can work on the system, with some limitations. Contact the Maine State Radon Section for more information.

Copies of the ASTM Standard can be purchased in PDF format at www.astm.org

For more information about healthy, energy-efficient homes, contact the Maine Indoor Air Quality Council at 207-626-8115.