by Nick Gromicko and Kenton Shepard ![]() Backdrafting is the reverse flow of gas in the flues of fuel-fired appliances that results in the intrusion of combustion byproducts into the living space. Many fuel-fired water heaters and boilers use household air and lack an induced draft, which makes them especially vulnerable to backdrafting when indoor air pressure becomes unusually low. Inspectors should try to spot evidence of backdrafting in homes. How does backdrafting happen? Fuel-fired water heaters, boilers, wall heaters, and furnaces are designed to exhaust the byproducts of combustion to the outdoors through a flue. These hot gases rise through the flue and exit the home because they are not as dense as indoor air. The pressure differential that allows for the release of combustion gases can be overcome by unusually low indoor air pressure caused by a high rate of expulsion of air into the outdoors through exhaust fans, fireplaces and dryers. When this happens, combustion gases can be sucked back into the house and may potentially harm or kill building occupants. Improperly configured flues or flue blockages can also cause backdrafting. How can InterNACHI inspectors test for backdrafting?
In summary, inspectors should try to spot evidence of backdrafting. Craftsman Home Inspections llc is a home inspection company proudly serving the Aurora CO and Denver CO Metro Areas. If you are looking for a Home Inspector in Aurora or Denver, please give us a call at 720-593-0383 or check us out online at CraftsmanColorado.com or simply schedule your home inspection below.
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by Nick Gromicko ![]() Attic pull-down ladders, also called attic pull-down stairways, are collapsible ladders that are permanently attached to the attic floor. Occupants can use these ladders to access their atticswithout being required to carry a portable ladder. Common Defects Homeowners, not professional carpenters, usually install attic pull-down ladders. Evidence of this distinction can be observed in consistently shoddy and dangerous work that rarely meets safety standards. Some of the more common defective conditions observed by inspectors include:
Relevant Codes The 2009 edition of the International Building Code (IBC) and the 2006 edition of the International Residential Code (IRC) offer guidelines regarding attic access, although not specifically pull-down ladders. Still, the information might be of some interest to inspectors. 2009 IBC (Commercial Construction): 1209.2 Attic Spaces. An opening not less than 20 inches by 30 inches (559 mm by 762 mm) shall be provided to any attic area having a clear height of over 30 inches (762 mm). A 30-inch (762 mm) minimum clear headroom in the attic space shall be provided at or above the access opening. 2006 IRC (Residential Construction): R807.1 Attic Access. Buildings with combustible ceiling or roof construction shall have an attic access opening to attic areas that exceed 30 square feet (2.8m squared) and have a vertical height of 30 inches (762 mm) or more. The rough-framed opening shall not be less than 22 inches by 30 inches, and shall be located in a hallway or readily accessible location. A 30-inch (762 mm) minimum unobstructed headroom in the attic space shall be provided at some point above the access opening. Tips that inspectors can pass on to their clients:
Craftsman Home Inspections llc is a home inspection company proudly serving the Aurora CO and Denver CO Metro Areas. If you are looking for a Home Inspector in Aurora or Denver, please give us a call at 720-593-0383 or check us out online at CraftsmanColorado.com or simply schedule your home inspection below.
SCHEDULE INSPECTION by Nick Gromicko and Kenton Shepard ![]() Backflow is the reversal of the normal and intended direction of water flow in a water system. Devices and assemblies known as backflow preventers are installed to prevent backflow, which can contaminate potable water supplies. Why is backflow a problem? Backflow is a potential problem in a water system because it can spread contaminated water back through a distribution system. For example, backflow at uncontrolled cross connections (cross-connections are any actual or potential connection between the public water supply and a source of contamination or pollution) can allow pollutants or contaminants to enter the potable water system. Sickness can result from ingesting water that has been contaminated due to backflow. Backflow may occur under the following two conditions: back-pressure: Back-pressure is the reverse from normal flow direction within a piping system as the result of the downstream pressure being higher than the supply pressure. This reduction in supply pressure occurs whenever the amount of water being used exceeds the amount of water being supplied (such as during water-line flushing, fire-fighting, or breaks in water mains). back-siphonage: Back-siphonage is the reverse from normal flow direction within a piping system that is caused by negative pressure in the supply piping (i.e., the reversal of normal flow in a system caused by a vacuum or partial vacuum within the water supply piping). Back-siphonage can occur when there is a high velocity in a pipe line, when there is a line repair or break that is lower than a service point, or when there is lowered main pressure due to high-water withdrawal rate (such as during fire-fighting or water-main flushing). Atmospheric Vacuum Breakers Backflow prevention for residences is most commonly accomplished through the use of atmospheric vacuum breakers (AVBs). AVBs operate by allowing the entry of air into a pipe so that a siphon cannot form. AVBs are bent at 90 degrees and are usually composed of brass. Compared with backflow preventer assembles, AVBs are small, simple and inexpensive devices that require little maintenance or testing. They have long life spans and are suitable for residential purposes such as sprinkler systems. InterNACHI inspectors can check for the following:
Types of Backflow Preventer Assemblies Some types of assemblies are common in commercial and agricultural applications but are rare for residential uses. The appropriate type of backflow preventer for any given application will depend on the degree of potential hazard. The primary types of backflow preventers appropriate for use at municipalities and utilities are:
Requirements for Testers and Inspectors A number of organizations, such as the American Water Works Association (AWWA) and the American Backflow Prevention Association (ABPA) offer certification courses designed to train professionals to test backflow preventers. Requirements for training vary by jurisdiction. Inspection of backflow preventers requires knowledge of installation requirements, although inspectors are not required to become certified. In summary, backflow preventers are designed to prevent the reverse flow of water in a potable water system. They come in a number of different types, each of which is suited for different purposes. Craftsman Home Inspections llc is a home inspection company proudly serving the Aurora CO and Denver CO Metro Areas. If you are looking for a Home Inspector in Aurora or Denver, please give us a call at 720-593-0383 or check us out online at CraftsmanColorado.com or simply schedule your home inspection below.
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