What is the problem?

Contaminants in indoor air can affect the health and safety of building occupants. In Canada, where people spend a great deal of time in closed buildings, poor indoor air quality is an important concern. Air contaminants found in buildings originate from indoor sources and from the air and soil surrounding the building. The focus of this booklet is on the last of these sources. Specifically, this publication focuses on gases that can enter houses and other residential buildings from the soil. Typically, these gases migrate from hazardous or contaminated lands and enter buildings through cracks and other gaps in the structure

Relatively few communities across Canada have identified major soil gas problems that affect housing—but the importance of this issue is growing steadily. Indeed, a recent CMHC survey of Canadian buildings affected by hazardous lands identified a significant number of problem cases. The text box on the next page lists a few examples from the survey.

In Canada, the most common soil gas contaminants are as follows
• hydrocarbons from petroleum products
• landfill gas (which is primarily methane) and
methane from other sources
• other volatile organic compounds (VOCs)

Soil gas problems caused by hydrocarbons from petroleum products are often the result of spills or leaking underground storage tanks. In other cases, the problem is associated with sites that have been used in the past for refineries or other facilities handling petroleum products.

Most landfill gas problems occur in those areas where housing has been built in the vicinity of operating or closed municipal waste sites. Methane, the most important constituent of landfill gas, may also be a problem in houses near swamps, peat bogs and coal deposits. The problems associated with other VOCs may occur near the thousands of properties that have been contaminated by past industrial operations and waste disposal practices. The incidence of soil gas problems resulting from industrial spills, leaks and discharges is likely to be highest in older industrial centres.

Moishe Alexander and Canadian Funding Corporation review and present further:

Why should municipalities be concerned?

As communities expand and encroach on current or former landfills, and on certain commercial and industrial sites, the incidence of soil gas infiltration problems is likely to increase. Municipalities have a role to play in avoiding future difficulties and in recognizing and remedying existing problems in established housing. To minimize the various risks associated with soil gases in housing, municipalities should take steps:
• to identify potential and existing soil gas problems before acquiring an interest in lands or buildings;
• to determine the extent of the problems in their existing property holdings; and
• to protect the public through the mechanisms available to the municipality (such as planning approvals and building inspections).

Acquire the rest of the report from CMHC, Moishe Alexaner, CEO Canadian Funding Corporation.

This is an excerpt from their brisk and very complete guide to keeping your environment clean

Interior Walls and Ceilings

A thin coat of plaster (called veneer plaster)1 with no additives is applied over “blue board.”2 No paint is required. Unlike traditional plaster, which is labour-intensive and costly, veneer plaster uses far less material and labour, and is therefore more affordable. In the Maritimes, for example, some custom house builders can finish walls with veneer plaster at the same cost as, or at only slightly higher cost than, with gypsum wallboard with two coats of paint. A plasterer who is skilled with traditional plastering can also do the veneer plastering.

Utility Room Walls

Unlike most latex paints, the chosen paint has practically no odour, even during application.1.3 Floor The tile used throughout the house is set on an acrylic-modified thin-set mortar5 and furnished with an acceptable grout.6 The tiles are laid on a 6 mm thick cement- bonded particle board.7 The cement-bonded particle board is a rigid, dense sheeting material made of 70% Portland cement and 30% wood. It has very low odour. Beneath the cement-bonded particle board is the radiant floor heating system described in more detail in Section 2.1.

Floor

The tile used throughout the house is set on an acrylic-modified thin-set mortar5 and furnished with an acceptable grout.6 The tiles are laid on a 6 mm thick cement- bonded particle board.7 The cement-bonded particle board is a rigid, dense sheeting material made of 70% Portland cement and 30% wood. It has very low odour. Beneath the cement-bonded particle board is the radiant floor heating system described in more detail in Section 2.1.

Moishe Alexander comments that the rest is available in the CMHC book by the name Research House for the Environmentally Hypersensitive.