Small Gas Leaks in Your Home
by Building Inspector and Indoor Air Specialist, Dan Schilling
© Copyright 2002 Residential Inspections LLC, All Rights Reserved
The Scope of the Problem
Many people heat their homes with natural or liquid propane (LP) gas and may have other gas operating appliances in their homes. It is typically the stated policy of gas utility companies that all gas leaks, whether large or small, should be repaired. However, many repairmen do not understand the health significance of smaller gas leaks indoors. They are primarily concerned about the risk of fires associated with larger leaks and are unconcerned if the gas cannot be smelled. Therefore smaller gas leaks which cannot be seen or smelled are commonly overlooked and left unrepaired.
Wouldn't I smell gas if it were leaking?
Combustible gas has an offensive odorant added to it to help us smell it when leaks occur. This works well with larger gas leaks but not with small leaks. This is why electronic gas analyzers should be used to detect leakage indoors. These sensitive instruments can not only pinpoint small leaks at their source, but can also reach into areas where we cannot or would not place our noses. Further, there are many problems with the “must smell” theory. For example, a home which had eight gas leaks occurring simultaneously, were not even smelled by those living in the home. There are several reasons for this: First, not everybody has equally good senses of smell. Secondly, there are people who have no sense of smell at all. Thirdly, the ability of humans to perceive a specific odor can be diminished or eliminated immediately after acclamation to that odor. This is why people cannot smell perfume or cologne immediately after applying it on themselves, yet people passing by that individual can smell it just fine. Fourthly, the offensive odorant put into gas tends to dissipate rapidly with small leaks, becoming virtually undetectable even for people who have a good sense of smell. Fifthly, and most important is the fact that small indoor gas leaks can severely affect the health of people and animals living indoors.
What are the symptoms of inhaling gas?
As with any other indoor air contaminant, some of the symptoms associated with gas inhalation may be identical to symptoms associated with other indoor air contaminants. This is why it is so important to pay attention to all possible air contamination sources. The symptoms that have been directly associated with gas inhalation can include headaches, easy bruising, memory loss, severe leg aches, abdominal pain, recurrent infections, nausea, flu-like symptoms, irritability, tiredness, fatigue, and depression.
What is the likelihood of gas leaks in my home?
Approximately 8 out of 10 homes inspected will have gas leakage in one or more locations. Some may only have one or two leaks while others may have six or eight. The majority of these gas leaks are small in nature and pose no immediate danger such as causing the house to explode like in a Hollywood movie, but these leaks are still present and they will be leaking gas continuously indoors, only to be inhaled by the occupants.
How do gas leaks start?
Gas leaks can remain from oversights during the installation of piping and appliances. More often, they occur from aged sealant at the pipe fittings or dried out grease inside of appliance operating valves. Leaks can also begin from valve handles which migrate loose or from pipes that have been bumped.
How do I get my home checked for leaks?
Some home inspectors offer gas leak detection as an ancillary service during home inspections. If you are already in your home, you can call a home inspector, plumber, heating contractor or the utility company to have your gas system inspected. Leakage checks should be performed with an electronic gas analyzer with the sensor adjusted to be as sensitive as possible. Checks should be performed at indoor gas meters, pressure relief valve, main shut off, pipeline fittings, appliance shut off valves, and operating controls. All gas burning appliances should be checked including kitchen ranges, clothes dryers, wall heaters, fireplaces, furnaces and water heaters.
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