Solar energy offers considerable advantages over conventional energy systems by nullifying flaws in those systems long considered to be unchangeable. Solar power for home energy production has its flaws, too, which are outlined in another article, but they're dwarfed by the advantages listed below.
![]() Adjustable steel columns, also known as screw jacks and beam jacks, are hollow steel posts designed to provide structural support. An attached threaded adjustment mechanism is used to adjust the height of the post. A few facts about adjustable steel columns:
Inspectors will not be able to identify paint as rust-inhibitive. In dry climates where rust is not as much of a problem, rust-inhibitive paint may not be necessary. Visible signs of rust constitute a potential defect.
“Acid rain,” like “global warming,” is a phenomenon whose very existence is disputed by some. In fact, evidence of acid rain has been observed in industrialized cities around the world since the mid-1800s. “Acid rain” describes the mixture of wet and dry deposits from the atmosphere which contain high amounts of nitric and sulfuric acids that result from both natural and man-made emissions. Its effects on structures and homes are very real. Inspectors can learn more about acid rain and its destructive signs on metal and stone components of the exteriors of homes.
Acid rain is formed when the chemical precursors of nitric and sulfuric acids -- sulfur dioxide (SO2) and nitrogen oxide (NOx), respectively -- combine with natural sources of acidic particles, such as volcanoes and decaying vegetation. When this mixture reacts with oxygen, water and other chemicals (including pollutants such as carbon dioxide), the result is acid rain, which can be carried by rain, and even snow, frost, fog and mist, which, in turn, runs off into soil and groundwater. According to the EPA, about two-thirds of all SO2 and one-quarter of the NOx emissions in the atmosphere in the U.S. result from power plants that burn fossil fuels (primarily coal), as well as vehicles and agricultural equipment that rely on gasoline. It is fair to say that any industrialized region with power plants that burn fossil fuels will show some wear on its surrounding structures from acid rain. But buildings in arid regions are at greater risk because of dry deposition, in which acidic pollutants are present in gases, smoke and dust, which tend to stick to buildings, cars and other structures. When it rains or snows, the subsequent wet deposition of nitric and sulfuric acids becomes even more acidic, which then washes into the soil and aquifers. The more obvious impacts of acid rain can be seen on particular types of stone, such as limestone and marble buildings, monuments, statues and headstones. The weathering pits and canyons can obliterate the lettering and features of such structures to a brutal degree, depending on the type of stone and other environmental conditions. Acid rain can also corrode bronze and other metals, such as nickel, zinc, copper, and carbon-steel, as evidenced by streaks and discoloration on bridges and other metal structures, such as many commercial buildings. Not all buildings or structures suffer the effects of acid rain. How big of a threat it is can be determined by the chemical makeup and interactions of a building's materials. Limestone and marble, which, historically, were used widely because of their availability and workability by artisans, are especially susceptible because they are composed of calcite, or calcium carbonate, which acidic chemicals can dissolve easily. To observe this first-hand, drop a piece of blackboard chalk into a glass of vinegar. Drop another piece of chalk into a glass of water. The next morning, you’ll see the alarming difference. Modern buildings tend to use granite, which is composed of silicate minerals, such as quartz and feldspar. Silicate minerals resist acidic attacks from the atmosphere. Sandstone, another silica material, is also resistant. Stainless steel and aluminum tend to hold up better. But all minerals, including those found in paint and road overlay, are affected, to some degree. Because of the switchover in the use of certain building materials in the post-Industrial Era, historic buildings, more so than modern ones, tend to show the destructive outcome of acid rain since we first began burning fossil fuels for energy. London’s Westminster Abbey, the Colosseum in Rome, and India’s Taj Mahal all show signs of degradation brought on by atmospheric nitric and sulfuric acids. Plant life and wildlife are also affected. The pH -- or alkalinity and acidity -- of lake water, for example, tends to re-stabilize and maintain equilibrium when contaminated by acid rain. However, soil and trees can become irreparably harmed when their pH is disturbed to the extent that their natural abilities to compensate for chemical fluctuations in the environment are thwarted. Soil contains naturally occurring mercury and aluminum, which are normally poisonous for plant life. But plants can survive when the nutrient base of the soil remains healthy, giving them a strong buffering capacity. Acid rain, however, destroys the environmental balance, and these naturally occurring chemical threats suddenly become fatal. The plants' "immune systems," made stronger by the surrounding soil, become compromised. The plants and trees may die a slow death due to nutrient starvation, oxygen deprivation, injured leaves that cannot recover, and/or their bark will become damaged and vulnerable to mold, fungi and wood-destroying insects. When the environment is under continual attack by the deadly effects of acid rain, the odds of survival for other resident plant, animal and insect species diminish as the ecosystem is thrown out of its natural balance. On the flipside, NASA researchers recently discovered that one species of swampland bacteria's ability to produce methane -- a greenhouse gas that contributes to global warming -- is actually inhibited by acid rain. The EPA’s Acid Rain Program got underway in 1995 (after being enacted by Congress in 1990), which continues to seek to reduce SO2 and NOx emissions to below 1980 pollution levels. The program originally targeted coal-burning electricity plants, and has expanded to include other types of industry that burn coal, oil and gas, too. While the EPA touts some success in bringing down some polluters’ output by 40%, critics charge that because the program permits emission “allowance trading” among its participants, the larger industrial polluters simply pay the $2,000-per-ton fine for exceeding SO2 and NOx limits. The EPA, however, has embraced a market-friendly approach while shooting for overall target reductions. The primary problem with acid rain, of course, is that there is no way to contain it. It blows with the wind and is captured and carried by localized weather systems. Although the deterioration which acid rain causes may be slow, it is persistent. And until we shift our reliance on fossil fuels by using various types of green energy (wind, solar, etc.), we will continue to witness the destructive consequences in all aspects of our environment, both natural and man-made, for decades to come. Homeowners can mitigate the environmental effects of acid rain by modifying their purchasing and traveling habits, and by using building materials that are better able to withstand the corrosive effects of this modern scourge. Inspectors can become more familiar with the problems posed by acid rain by investigating the types of building materials used, and by contacting their local EPA representative for up-to-date statistics on pollution levels for their specific area. ![]() by Kenton Shepard During the inspection, I ran into a neighbor who told me that the roof of another garage, identical to the one pictured above two buildings down, had collapsed the previous winter under a snow load. So, I decided to keep my eyes wide open as I went through the garage. Some defects you have to search for, and some are pretty obvious. These first two defects were obvious from the doorway:
Trusses cannot be altered in any way without the approval of a structural engineer. When you see plywood gussets added at truss connections like these triangular gussets, then an alteration of some sort has obviously been made and you have to recommend evaluation by a structural engineer. So, that condition went into the report. Trusses are designed to bear loads at very specific points. Typical roof trusses should not touch any interior walls and should bear only on the exterior walls. The two trusses at the left of the above photo are bearing on an offset portion of the garage wall. A portion of the structural roof load was being transferred to the bottom chords of the trusses at a point at which they were not designed to support a load. Then I walked over and looked more closely at the connections where the trusses attached to the wall and found these problems:
These trusses would have best been supported by bearing directly on wall framing. The next best solution would be an engineer-designed ledger or engineer-specified hardware. And that may have been how they were originally built, but by the time I inspected them, 24-foot roof trusses were supported by joist hangers designed to support 2x4 joists. The hangers were fastened with four gold deck screws each. Gold deck screws are designed to resist withdrawal. Fasteners for metal connectors such as joist hangers are designed to resist shear. Withdrawal force is like the force which would be generated if you grabbed the head of a fastener with pliers and tried to pull it straight out. Shear force is what’s used if you take a pair of heavy-duty wire cutters and cut the fastener. Fasteners designed to resist withdrawal, such as deck screws, are weak in shear resistance. So, there were drastically undersized metal connectors fastened by badly under-strength fasteners. To make matters worse, the screws were fastened through drywall, which doesn’t support the shaft of the screw and degrades the connection even further. And, once I looked really closely, I found more truss alterations. The gangnail had been pried loose and the spikes which form the actual mechanical connection were destroyed. In their place were a couple of bent-over nails. This condition represented a terrific loss of strength and this roof, too, was a candidate for catastrophic structural failure. In summary, look carefully at connections for problems which may lead to structural issues, as some are more urgent than others. Be sure to call these out in your report. Also, all electrical receptacles in garages must be GFCI-protected, without exception. 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 Set One 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 Pliers Use 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 Wrench Adjustable 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. |
AuthorIowa Home inspections CategoriesArchives
March 2016
|