By Barry Stone
Dear Barry,
In a recent column, you stated that the drainpipe for a water heater must terminate at the exterior of a building, even when the water heater is installed in a garage. As a building inspector, I should point out that the code section which says the drain shall extend to the outside of the building is followed by the sentence that reads, "Such drains may terminate at other approved locations." Many building departments, as a matter of policy, use the latter sentence to allow the drain to terminate at the garage floor. Draining to the garage floor is an accepted practice within the building industry because garage walls are elevated above the slab and because garage floors are sloped to promote drainage toward the driveway.
-- Larry
Dear Larry,
Thank you for reopening this topic of hot controversy among building inspectors. As you know, there is no shortage of divergent opinions among building officials and inspectors. Given the many generalities in the code, it sometimes seems that we could debate endlessly the number of angels who can dance on the head of a pin. But getting back to water heater drain pipes:
The code defines itself as a minimum standard. Therefore, the prescription to terminate an overflow pipe at the exterior of a building can be regarded as a minimum requirement. The implied intent of this standard is to prevent water damage to the interior of the building and to its contents. The code statement "such drains may terminate at other approved locations" should be understood in the light of this minimum standard and its intent.
Other approved locations should be those which likewise prevent water damage. Examples of other approved locations, therefore, should be standpipes, laundry sinks, floor drains, and the like.
The fact that a garage slab is sloped for drainage is overruled by the storage of personal property typically found on garage floors. Such storage commonly includes wood furniture, boxes of books, clothing, and sundry valuables and nearly-valuables, all subject to costly damage if exposed to water. On the safety side of the issue, rust damage could occur to the bottoms of stored metal containers such as cans of thinner and other combustible fluids.
Owing to these considerations, I am still persuaded that exterior termination of the overflow pipe is the more practical solution. This, of course, is my opinion, and building departments are free to interpret the code differently. But there remain, in my view, practical reasons for not terminating an overflow pipe at the floor of a garage.
Copyright 2001-2006 Barry Stone. Distributed by Inman News Features
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