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Chimneys are among the heaviest and most structurally vulnerable of all exterior components of a building. Accidents caused by their collapse can lead to death. A collapse can also cause costly structural damage to the building and its surroundings. Inspection, maintenance and preparedness are critical safeguards against chimney collapse.Wind and other elements may cause an already weakened chimney to collapse. An elderly man in Britain was crushed by a wind-toppled chimney as it fell from the roof of the managed-care facility where he lived. This case is, unfortunately, fairly unremarkable, as such accidents occur often for a variety of reasons -- from weathering and wind, to falling tree limbs and poor design.
Chimneys collapse by the hundreds during major earthquakes, typically snapping at the roofline. More than half of the homes in Washington State inspected by the Federal Emergency Management Agency (FEMA) following the Nisqually Earthquake in 2001 sustained chimney damage. Chimney collapses were widely reported following the massive-magnitude 7.1 earthquake that struck New Zealand in September 2010. Earthquake damage and injuries can be caused, in large part, by bricks and stones as they fall from chimneys onto vehicles, structures and people. These collapses happen suddenly and without warning. Collapses can also cause implosion-type destruction as the chimney makes its way through the roof and attic, demolishing part of the living space and injuring occupants below. For these reasons, it is crucial that chimneys, especially in seismically active regions, be inspected periodically for signs of weakening. Following an earthquake, it is even more vital that chimneys be inspected for indications of imminent or future collapse. Chimneys should be inspected for the following defects:
The following additional precautions may be taken:
In addition to collapse hazards, leaning chimneys can also make using the fireplace dangerous. Hearth cracks, side cracks in the fireplace, openings around the fireplace, and chimney damage all present the risk that sparks or smoke will enter the living space or building cavities. Check for evidence of fireplace movement. Following an earthquake, homeowners should have their chimney inspected before using the fireplace. Commercial chimney collapses are rare, but they deserve mention due to the devastation they cause. In one terrible incident in central India, more than 100 workers were killed when a 900-foot (275-meter) tall chimney collapsed on a construction site. One of the worst construction site disasters in recent history, the collapse was blamed on heavy rain. While safety standards are generally more stringent outside of India, commercial chimneys everywhere require inspection. In summary, chimneys should be inspected to prevent deadly, expensive collapses. by Nick Gromicko, CMI®
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The following items are essential tools, but this list is by no means exhaustive. Feel free to ask an InterNACHI inspector during your next inspection about other tools that you might find useful.
1. Plunger A clogged sink or toilet is one of the most inconvenient household problems that you will face. With a plunger on hand, however, you can usually remedy these plumbing issues relatively quickly. It is best to have two plungers -- one for the sink and one for the toilet. 2. Combination Wrench SetOne end of a combination wrench set is open and the other end is a closed loop. Nuts and bolts are manufactured in standard and metric sizes, and because both varieties are widely used, you’ll need both sets of wrenches. For the most control and leverage, always pull the wrench toward you, instead of pushing on it. Also, avoid over-tightening. 3. Slip-Joint PliersUse slip-joint pliers to grab hold of a nail, a nut, a bolt, and much more. These types of pliers are versatile because of the jaws, which feature both flat and curved areas for gripping many types of objects. There is also a built-in slip-joint, which allows the user to quickly adjust the jaw size to suit most tasks. 4. Adjustable WrenchAdjustable wrenches are somewhat awkward to use and can damage a bolt or nut if they are not handled properly. However, adjustable wrenches are ideal for situations where you need two wrenches of the same size. Screw the jaws all the way closed to avoid damaging the bolt or nut. 5. Caulking Gun Caulking is the process of sealing up cracks and gaps in various structures and certain types of piping. Caulking can provide noise mitigation and thermal insulation, and control water penetration. Caulk should be applied only to areas that are clean and dry. 6. Flashlight None of the tools in this list is of any use if you cannot visually inspect the situation. The problem, and solution, are apparent only with a good flashlight. A traditional two-battery flashlight is usually sufficient, as larger flashlights may be too unwieldy. 7. Tape Measure Measuring house projects requires a tape measure -- not a ruler or a yardstick. Tape measures come in many lengths, although 25 feet is best. Measure everything at least twice to ensure accuracy. 8. Hacksaw A hacksaw is useful for cutting metal objects, such as pipes, bolts and brackets. Hacksaws look thin and flimsy, but they’ll easily cut through even the hardest of metals. Blades are replaceable, so focus your purchase on a quality hacksaw frame. 9. Torpedo Level Only a level can be used to determine if something, such as a shelf, appliance or picture, is correctly oriented. The torpedo-style level is unique because it not only shows when an object is perfectly horizontal or vertical, but it also has a gauge that shows when an object is at a 45-degree angle. The bubble in the viewfinder must be exactly in the middle -- not merely close. 10. Safety Glasses / Goggles For all tasks involving a hammer or a power tool, you should always wear safety glasses or goggles. They should also be worn while you mix chemicals. 11. Claw Hammer A good hammer is one of the most important tools you can own. Use it to drive and remove nails, to pry wood loose from the house, and in combination with other tools. They come in a variety of sizes, although a 16-ounce hammer is the best all-purpose choice. 12. Screwdriver Set It is best to have four screwdrivers: a small and large version of both a flathead and a Phillips-head screwdriver. Electrical screwdrivers are sometimes convenient, but they're no substitute. Manual screwdrivers can reach into more places and they are less likely to damage the screw. 13. Wire Cutters Wire cutters are pliers designed to cut wires and small nails. The side-cutting style (unlike the stronger end-cutting style) is handy, but not strong enough to cut small nails. 14. Respirator / Safety Mask While paints and other coatings are now manufactured to be less toxic (and lead-free) than in previous decades, most still contain dangerous chemicals, which is why you should wear a mask to avoid accidentally inhaling. A mask should also be worn when working in dusty and dirty environments. Disposable masks usually come in packs of 10 and should be thrown away after use. Full and half-face respirators can be used to prevent the inhalation of very fine particles that ordinary facemasks will not stop. 15. Duct Tape This tape is extremely strong and adaptable. Originally, it was widely used to make temporary repairs to many types of military equipment. Today, it’s one of the key items specified for home emergency kits because it is water-resistant and extremely sticky. by Nick Gromicko, CMI® and Ben Gromicko 1/23/2022 0 Comments BackdraftingBackdrafting 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. by Nick Gromicko, CMI® and Kenton Shepard 1/6/2022 0 Comments Defrost Cycle of a Heat PumpAccording to the InterNACHI Residential Standards of Practice, a home inspection is a non-invasive, visual examination of a residential dwelling that is designed to identify observed material defects within specific components of that dwelling. Part of the home inspection includes the inspection, identification and description of the heating system, which includes heat pumps.
The inspector is required to inspect the heating systems using normal operating controls, and describe the energy source and heating method. The inspector’s report shall describe and identify, in written format, the inspected heating system, and shall identify material defects observed. In order to perform an inspection according to the Standards of Practice, an inspector must apply the knowledge of what he/she understands about the different types of residential heating systems. To inspect and identify a particular heating system, describe its heating method, and identify any material defects observed, an inspector should be able to explain and discuss with their client:
Here, we cover some fundamentals of a particular heating system called a heat pump using non-invasive, visual-only inspection techniques. We also discuss its defrost cycle. It is up to the inspector’s judgment as to how detailed the inspection and report will be. For example, the inspector is not required to determine the capacity or BTU of the inspected heating system, but many inspectors record that detailed information in their reports. How it Operates When a heat pump is operating in the heating mode or heat cycle, the outdoor air is relatively cool and the outdoor coil acts as an evaporator. Under certain conditions of temperature and relative humidity, frost might form on the surface of the outdoor coil. The layer of frost will interfere with the operation of the heat pump by making the pump work harder and, therefore, inefficiently. The frost must be removed. A heat pump has a cycle called a defrost cycle, which removes the frost from the outdoor coil. A heat pump unit will defrost regularly when frost conditions occur. The defrost cycle should be long enough to melt the ice, and short enough to be energy-efficient. In the defrost cycle, the heat pump is automatically operated in reverse, for a moment, in the cooling cycle. This action temporarily warms up the outdoor coil and melts the frost from the coil. In this defrost cycle, the outdoor fan is prevented from turning on when the heat pump switches over, and the temperature rise of the outdoor coil is accelerated and increased. The heat pump will operate in the defrost cycle until the outdoor coil temperature reaches around 57° F. The time it takes to melt and remove accumulated frost from an outdoor coil will vary, depending on the amount of frost and the internal timing device of the system. Interior Heating Element During this defrost cycle with older heat pumps, the indoor unit might be operating with the fan blowing cool air. To prevent cool air from being produced and distributed inside the house, an electric heating element can be installed and engaged at the same time as the defrost cycle. In defrost mode, this heating element will automatically turn on, or the interior blower fan will turn off. The heating component is wired up to the second stage of a two-stage thermostat. The Typical Cycle The components that make up the defrost cycle system includes a thermostat, timer and a relay. There is a special thermostat or sensor of the defrost cycle system, often referred to as the frost thermostat. It is located on the bottom of the outdoor coil where it can detect the temperature of the coil. When the outdoor coil temperature drops to around 32° F, the thermostat closes the circuit and makes the system respond. This causes an internal timer to start. Many heat pumps have a generic timer that energizes the defrost relays at certain intervals of time. Some generic timers will energize the defrost cycle every 30, 60 and 90 minutes. The defrost relays turn on the compressor, switch the reversing valve of the heat pump, turn on the interior electric heating element, and stop the fan at the outdoor coil from spinning. The unit is now in the defrost cycle. The unit remains in the defrost cycle (or cooling cycle) until the thermostat on the bottom of the outdoor coil senses that the outdoor coil temperature has reached about 57° F. At that temperature, the outdoor coil should be free of frost. The frost thermostat opens the circuit, stops the timer, then the defrost cycle stops, the internal heater turns off, the valve reverses, and the unit returns to the heating cycle. A typical defrost cycle might run from 30 seconds to a few minutes. The defrost cycles should repeat regularly at timed intervals. An inspector should not observe a rapid cycling of the defrost operation. In summary, certain conditions can force a heat pump into a defrost cycle (or cooling cycle) where the fan in the outdoor coil is stopped, the indoor fan is stopped or electric heat is turned on, the frost melts and is removed from the outdoor coils. When the frost thermostat is satisfied or a certain pre-set time period elapses, the outdoor fan comes back on, and the heat pump goes back into the heating cycle. One problem of many older heat pump systems is that the unit will operate in the defrost cycle regardless of whether ice is present. On these systems, if it’s cold outside, the defrost cycle might turn on when it is not needed. If the defrost cycle is not functioning properly, the outdoor coil will appear like a big block of ice, making the unit non-functional. Damage could result if the heat pump operates without a functional, normal-operating defrost cycle. Causes of Frost There are many reasons why an inspector might find frost and ice stuck on an outdoor coil of a heat pump that is not properly defrosting. The cause of the frost and ice problem may include:
The Best Techniques There are three cycles of a heat pump: heating, cooling and defrost cycles. We learned about the defrost cycle of a heat pump. According to the InterNACHI Standards of Practice, the inspector is required to inspect the heating systems using normal operating controls and describe the heating method. The inspector’s report shall describe and identify, in written format, the inspected heating system, and shall identify material defects observed. To learn how to properly inspect a heat pump system using the best non-invasive, visual-only inspection techniques as required by the Standards of Practice, an inspector should be professionally trained. by Nick Gromicko, CMI® and Ben Gromicko |
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