by Nick Gromicko, CMI® and Kenton Shepard

Central humidifier
Humidifiers are devices that humidify air so that building occupants are comfortable. Central humidifiers are hard-wired into a house’s plumbing and forced-air heating systems.

What is humidity? 

Humidity refers to the amount of moisture in the air. “Relative humidity” signifies the amount of moisture in the air relative to the maximum amount of water the air can contain before it becomes saturated. This maximum moisture count is related to air temperature in that the hotter the air is, the more moisture it can hold. For instance, if indoor air temperature drops, relative humidity will increase.

How do central air humidifiers work?

Central air humidifiers are integrated into the forced-air heating system so that they humidify air while it is being heated. The water that is used by the device is pumped automatically into the humidifier from household plumbing, unlike portable humidifiers, which require the user to periodically supply water to the device. Humidifiers are available in various designs, each of which turns liquid water into water vapor, which is then vented into the house at an adjustable rate.

Why humidify air?

Certain airborne pathogens, such as those that cause the flu, circulate easier in dry air than in moist air. Moist air also seems to soothe irritated, inflamed airways. For someone with a cold and thick nasal secretions, a humidifier can help thin out the secretions and make breathing easier.

Indoor air that is too dry can also cause the following problems:

  • damage to musical instruments, such as pianos, guitars and violins;
  • dry skin;
  • peeling wallpaper;
  • static electricity, which can damage sensitive electrical equipment, cause hair to stick up, and can be painful or annoying; and
  • cracks in wood furniture, floors, cabinets and paint.

Central Humidifier Dangers

Humidifiers can cause various diseases. The young, elderly and infirm may be particularly at risk to contamination from airborne pollutants, such as bacteria and fungi. These can grow in humidifiers and get into the air by way of the vapor where it can be breathed in. Some of the more common diseases and pathogens transmitted by humidifiers are:

  • Legionnaires’ Disease. Health problems caused by this disease range from flu-like symptoms to serious infections. This problem is generally more prevalent with portable humidifiers because they draw standing water from a tank in which bacteria and fungi can grow;
  • thermophilic actinomycetes. These bacteria thrive at temperatures of 113° to 140° F and can cause hypersensitivity pneumonitis, which is an inflammation of the lungs; and
  • “humidifier fever,” which is a mysterious and short-lived, flu-like illness marked by fever, headache, chills and malaise, but without prominent pulmonary symptoms. It normally subsides within 24 hours without residual effects.

Other problems associated with humidifiers include:

  • accumulation of white dust from minerals in the water. These minerals may be released in the mist from the humidifier and settle as fine white dust that may be small enough to enter the lungs. The health effects of this dust depend on the types and amounts of dissolved minerals. It is unclear whether these minerals cause any serious health problems;
  • moisture damage due to condensation. Condensed water from over-humidified air will appear on the interior surfaces of windows and other relatively cool surfaces. Excessive moisture on windows can damage windowpanes and walls, but a more serious issue is caused when moisture collects on the inner surfaces of exterior walls. Moisture there can ruin insulation and rot the wall, and cause peeling, cracking or blistering of the paint; and
  • accumulation of mold. This organic substance grows readily in moist environments, such as a home moistened by an over-worked humidifier. Mold can be hazardous to people with compromised immune systems.

Designs and MaintenanceHumidistat

  • drum-type humidifier:  has a rotating spongy surface that absorbs water from a tray. Air from the central heating system blows through the sponge, vaporizing the absorbed water. The drum type requires care and maintenance because mold and impurities can collect in the water tray. According to some manufacturers’ instructions, this tray should be rinsed annually, although it usually helps to clean it several times per heating season.
  • flow-through or “trickle” humidifier:  a higher quality though more expensive unit than the drum-type, which allows fresh water to trickle into an aluminum panel. Air blows through the panel and forces the water to evaporate into the air stream. Excess water exits the panel into a drain tube. This design requires little maintenance because the draining water has a “self-cleaning” effect and, unlike the drum-type humidifier, there is no stagnant water.

Other tips that InterNACHI inspectors can pass on to their clients:

  • If equipped with a damper, it should be closed in the summer and opened in the winter. The damper may appear as a knob that can be set to “summer” or “winter” setting, or it may be a piece of metal that can be inserted to cover the duct opening.
  • The humidifier is controlled by a humidistat, which must be adjusted daily. Some new models do this automatically, although most require daily attention from building occupants. The humidistat should contain a chart that can be used to identify the proper setting based on the outdoor temperature. If this adjustment is not performed, condensation will likely collect on cool surfaces and potentially lead to mold or wood rot. Many homeowners do not know that this calibration is necessary.
  • The furnace might need to be checked for rust. Some humidifiers are installed inside the plenum of the furnace, which can be damaged by rust if the humidifier leaks.
  • Central humidifiers may have a solid core that should be replaced each year. The manufacturer’s instructions should be consulted regarding this replacement.
In summary, central humidifiers are used to humidify air to make it more comfortable, but they can cause health problems and building damage if they are not properly maintained.  This article is from InterNACHI and can be found at https://www.nachi.org/central-humidifiers.htm.

by Nick Gromicko, CMI® and Kenton Shepard

Arc-fault circuit interrupters (AFCIs) are special types of electrical receptacles or outlets and circuit breakers designed to detect and respond to potentially dangerous electrical arcs in home branch wiring.
How do they work?
AFCIs function by monitoring the electrical waveform and promptly opening (interrupting) the circuit they serve if they detect changes in the wave pattern that are characteristic of a dangerous arc. They also must be capable of distinguishing safe, normal arcs, such as those created when a switch is turned on or a plug is pulled from a receptacle, from arcs that can cause fires. An AFCI can detect, recognize, and respond to very small changes in wave pattern.
What is an arc?
When an electric current crosses an air gap from an energized component to a grounded component, it produces a glowing plasma discharge known as an arc. For example, a bolt of lightening is a very large, powerful arc that crosses an atmospheric gap from an electrically charged cloud to the ground or another cloud. Just as lightning can cause fires, arcs produced by domestic wiring are capable of producing high levels of heat that can ignite their surroundings and lead to structure fires.
According to statistics from the National Fire Protection Agency for the year 2005, electrical fires damaged approximately 20,900 homes, killed 500 people, and cost $862 million in property damage. Although short-circuits and overloads account for many of these fires, arcs are responsible for the majority and are undetectable by traditional (non-AFCI) circuit breakers.
Where are arcs likely to form?
Arcs can form where wires are improperly installed or when insulation becomes damaged. In older homes, wire insulation tends to crystallize as it ages, becoming brittle and prone to cracking and chipping. Damaged insulation exposes the current-carrying wire to its surroundings, increasing the chances that an arc may occur.
Situations in which arcs may be created:

  • electrical cords damaged by vacuum cleaners or trapped beneath furniture or doors.
  • damage to wire insulation from nails or screws driven through walls.
  • appliance cords damaged by heat, natural aging, kinking, impact or over-extension.
  • spillage of liquid.
  • loose connections in outlets, switches and light fixtures.
Where are AFCIs required?
Locations in which AFCIs are required depend on the building codes adopted by their jurisdiction.
The 2006 International Residential Code (IRC) requires that AFCIs be installed within bedrooms in the following manner:

E3802.12 Arc-Fault Protection of Bedroom Outlets. All branch circuits that supply120-volt, single-phase, 15- and 20-amp outlets installed in bedrooms shall be protected by a combination-type or branch/feeder-type arc-fault circuit interrupter installed to provide protection of the entire branch circuit.

Exception: The location of the arc-fault circuit interrupter shall be permitted to be at other than the origination of the branch circuit, provided that:
  1. The arc-fault circuit interrupter is installed within 6 feet of the branch circuit overcurrent device as measured along the branch circuit conductors, and
  2. The circuit conductors between the branch circuit overcurrent device and the arc-fault circuit interrupter are installed in a metal raceway or a cable with metallic sheath.
The National Electrical Code (NEC) offers the following guidelines concerning AFCI placement within bedrooms:
Dwelling Units. All 120-volt, single phase, 15- and 20-ampere branch circuits supplying outlets installed in dwelling unit in family rooms, dining rooms, living rooms, parlors, libraries, dens, sun rooms, recreation rooms, closets, hallways, or similar rooms or areas shall be protected by a listed arc-fault circuit interrupter, combination-type installed to provide protection of the branch circuit.
Home inspectors should refrain from quoting exact code in their reports. A plaintiff’s attorney might suggest that code quotation means that the inspector was performing a code inspection and is therefore responsible for identifying all code violations in the home.  Some jurisdictions do not yet require their implementation in locations where they can be helpful.
What types of AFCIs are available?
AFCIs are available as circuit breakers for installation in the electrical distribution panel.

Nuisance Tripping

An AFCI might activate in situations that are not dangerous and create needless power shortages. This can be particularly annoying when an AFCI stalls power to a freezer or refrigerator, allowing its contents to spoil. There are a few procedures an electrical contractor can perform in order to reduce potential “nuisance tripping,” such as:
  • Check that the load power wire, panel neutral wire and load neutral wire are properly connected.
  • Check wiring to ensure that there are no shared neutral connections.
  • Check the junction box and fixture connections to ensure that the neutral conductor does not contact a grounded conductor.
Arc Faults vs. Ground Faults
It is important to distinguish AFCI devices from Ground Fault Circuit Interrupter (GFCI) devices. GFCIs detect ground faults, which occur when current leaks from a hot (ungrounded) conductor to a grounded object as a result of a short-circuit. This situation can be hazardous when a person unintentionally becomes the current’s path to the ground. GFCIs function by constantly monitoring the current flow between hot and neutral (grounding) conductors, and activate when they sense a difference of 5 milliamps or more. Thus, GFCIs are intended to prevent personal injury due to electric shock, while AFCIs prevent personal injury and property damage due to structure fires.
In summary, AFCIs are designed to detect small arcs of electricity before they have a chance to lead to a structure fire.  This article is from InterNACHI and can be found at https://www.nachi.org/arc-fault-circuit-interrupters.htm.

by Nick Gromicko, CMI®

Synthetic Stucco

Synthetic stucco is quite different from historic stucco.  Historic stucco is basically a plaster made with water, sand and lime.  While the composition of stucco has changed over time, it has always been applied wet over a brick, stone or wood surface to form the visible outside layer of a wall.

Synthetic stucco is foamboard and fiberglass mesh attached to a wall that is covered with a polymer-based material which is then textured to look like historic stucco.  It is technically known as an exterior insulation and finish system, or EIFS.  It has been in use in Europe since the 1950s, and in the U.S. since the late ‘60s.  It is often used on wood-framed houses.
Why is water damage a concern?
Any building material used on the exterior of residential homes will allow water or water vapor that finds its way inside to eventually escape back to the atmosphere.  EIFS itself, however, blocks the movement of water and water vapor – it does not “breathe.”  This, coupled with interior vapor barriers that are often required by building code, can lead to prolonged moisture intrusion and, eventually, rotting of materials.
Water can find its way inside through any cracks that have developed, or through any areas where the EIFS is jointed with a different material, such as door and window frames, or at the roof.  If the EIFS continues below ground level, any cracks or openings in the finish will allow moisture, as well as wood-destroying organisms, such as termites, inside.  When prolonged moisture intrusion of the wood behind the EIFS reaches 30%, rotting will occur.

Has water damage occurred or is it likely to occur? 

A preliminary visual inspection may reveal if water damage is actively occurring, as well as whether it is likely to occur due to improperly installed synthetic stucco. There have been many reported cases of EIFS manufacturer installation instructions not being followed correctly by builders, leading to problems.  It’s a good idea for inspectors to understand some of the methods of installation so that they can check some likely areas of moisture intrusion.

A few places to start visual inspection include:

  • ground contact:  EIFS should not continue down a wall into the ground.  It should terminate no less than 6 inches from finished ground level.  The bottom lip of the EIFS should also be properly wrapped and sealed;
  • roof flashing:  Kickout flashing should be installed where the EIFS meets the roofline.  If this is missing, there is a good possibility that water is entering the wall cavity.  Check for any areas that feel soft or are discolored;
  • joints around windows and doors:  Check caulking joints around windows and doors to make sure that there are no cracks, even small ones.  If wood on window or door frames feels soft, or it is discolored, water may have entered the wall assembly around the frame; and
  • areas of cracking or bulging:  If there are cracks in the EIFS itself, moisture will be able to infiltrate the wall assembly and cause rotting.  Bulges can indicate that coatings are delaminating or detaching from the polystyrene board.  These would be causes for concern.

Inspection for Moisture Intrusion

If a visual inspection reveals any evidence of damage, or that the EIFS has been installed incorrectly, further inspection may be in order.  An inspection for moisture intrusion consists of inserting a small probe through the outer wall into the frame area to determine the moisture content of the cavity.  The probe will leave holes about 1/8-inch in diameter, which can be sealed afterward.  The moisture readings can be gathered from typical problem areas, such as around windows and doors, roof eaves, near decks, and so on.  Once a more precise estimate of damage is obtained, options for repair can be evaluated by the homeowner.  These may include anything from additional caulking and sealing to removal and replacement of synthetic stucco sections.  Therefore, it is best to catch any possibility of water damage to EIFS at the earliest stage possible, before any lingering moisture has had time to cause rotting.
This article is from InterNACHI and can be found at https://www.nachi.org/water-damage-eifs.htm.

by Nick Gromicko, CMI® and Margaret Aey

A window well is semi-circular excavation that surrounds a basement window. It is typically constructed from a solid barrier made from corrugated galvanized metal, masonry, plastic or pressure-treated wood.

Window wells are usually installed for the following purposes:
  • emergency egress. If the window serves a living area — as opposed to an unfinished basement with exposed utilities (see our article on Non-Conforming Bedrooms) — emergency escape at a minimum of two locations is required. Window wells allow windows to be used by escaping occupants and emergency crews attempting to enter the house;
  • to prevent moisture damage to basement windows that are at or below grade. The window wells keep the soil away from openings in the foundation walls while still allowing proper grading and drainage away from the house; and
  • to allow sunlight into a below-grade room that would otherwise require artificial lighting.

Window Well Covers

Window wells are often covered to prevent injuries and falls, as well as to discourage small children,pets and wild animals from entering the wells and becoming injured and trapped. For instance, a deer fawn made news in Bountiful, Utah, after it was recovered safely after falling down a 12-foot-deep uncovered window well.   Although not required, window well covers are especially important if the space around the ground level opening is along a walkway or near a children’s play area.

Regarding their strength and operability, the 2007 edition of the International Code Council (ICC), Section 3.4, states that window well covers shall support “a minimum live load of 40 pounds per square foot. The cover shall be operable from within the window well without the use of tools or special knowledge, and shall require no more than 30 pounds of force to fully open.” These requirements ensure that an average-size adult would be able to pass through the window well safely during an emergency evacuation.

Covers (like the ones pictured above and built by the author out of polycarbonate sheets and Unistrut®) also prevent the accumulation of twigs, grass, mulch and blowing snow that would obscure sunlight and complicate emergency escape through the well. Covers may be locked from the inside to prevent unwanted intrusion.  However, locks and fasteners must be fully functional to be certain that the cover can be easily lifted from the inside.

Window well covers, however, can block sunlight, ventilation and emergency egress, especially if they become covered in snow and ice. It is the homeowner’s responsibility to make sure that the cover is cleared of snow and has not been frozen shut from ice. No items, such as garden hoses, potted plants or tools, should be placed on top of window well covers. Note that covers that are locked from the inside to prevent unlawful entry will be inaccessible to fire crews and first responders.
Construction 
Window well covers should be constructed from sturdy, high-quality material, such as plastic or metal. A window well cover that is made from metal (typically, aluminum or steel) is referred to as a grate and is implemented to protect against intrusion. Since metal grate covers have small openings, sometimes a plastic cover is installed over the metal grate to further prevent leakage and debris from entering the window well. In either case, the cover must fit over the entire opening, so it’s common for them to be custom-fitted.
Additional safety concerns include the following:
  • size. According to the 2006 edition of the International Residential Code (IRC), Section R310:

    The minimum horizontal area of the window well shall be 9 square feet, with a minimum horizontal projection and width of 36 inches.

    Even if the well seems large enough for members of a particular household, it might be a tight fit for a fully equipped firefighter;

  • structural damage to the barrier. Hydrostatic pressure and freeze-thaw cycles can exert a great deal of pressure on window wells and, over time, cause masonry to bend or crack. Check for:
    • spalling, bowing, cracking or leaning in concrete; 
    • cracking or bowing in plastic;
    • rust, bowing or rupture in metal; and
    • insect damage or cracks in wood.
  • improper drainage. Waterlogged window wells can easily leak through a window into the basement, especially following a heavy rain. Water intrusion can cause a variety of undesirable conditions, such as mold growth, wood decay, corrosion and insect damage. Check for a lack of sufficient cleaning and maintenance both in the window well and elsewhere. Homeowners should first make sure that gutters and downspouts are clear of debris, which can force water to overflow from the gutters and collect in the window well and other low areas. Dirt and debris should also be collected from the well. A qualified professional may be required to correct structural sources of drainage issues, such as soil erosion, insufficient or settled drainage stone, or the pulling away from the foundation of the barrier; and
  • lack of a ladder. The 2006 IRC, Section 310.2, states:

    Window wells with a vertical depth greater than 44 inches shall be equipped with a permanently affixed ladder or steps usable with the window in the fully open position.

Additional Tips for Homeowners

  • Window well covers can be screened or barred to provide pest-free ventilation.
  • Teach children to avoid window wells, even if they are covered and appear sturdy.
  • Practice exiting the window, window well and window cover so that any previously unnoticed obstacles can be removed. Repair or replace any equipment that does not function properly.
  • Speak with your local building department if you are unsure whether a window well is required in your home. Your jurisdiction may mandate special size restrictions.
  • Metal window wells can have rolled edges for safety against cuts.
  • Consult with your InterNACHI® inspector if you have additional concerns surrounding window wells, covers, moisture problems and emergency egress.
In summary, window wells are installed to allow emergency egress and to protect windows from damp soil, but improper installation and maintenance can lead to moisture damage and safety hazards, especially in an emergency.  Additionally, window well covers can be installed over window well openings to eliminate the risk of children, animals, and pedestrians from falling into the window well excavation.  This article is from InterNACHI and can be found at https://www.nachi.org/window-well-inspection.htm.

by Nick Gromicko, CMI®

 

Carbon monoxide (CO) is a colorless, odorless, poisonous gas that forms from incomplete combustion of fuels, such as natural or liquefied petroleum gas, oil, wood or coal.

Facts and Figures

  • 480 U.S. residents died between 2001 and 2003 from non-fire-related carbon-monoxide poisoning.
  • Most CO exposures occur during the winter months, especially in December (including 56 deaths, and 2,157 non-fatal exposures), and in January (including 69 deaths and 2,511 non-fatal exposures). The peak time of day for CO exposure is between 6 and 10 p.m.
  • Many experts believe that CO poisoning statistics understate the problem. Because the symptoms of CO poisoning mimic a range of common health ailments, it is likely that a large number of mild to mid-level exposures are never identified, diagnosed, or accounted for in any way in carbon monoxide statistics.
  • Out of all reported non-fire carbon-monoxide incidents, 89% or almost nine out of 10 of them take place in a home.

Physiology of Carbon Monoxide Poisoning

When CO is inhaled, it displaces the oxygen that would ordinarily bind with hemoglobin, a process the effectively suffocates the body. CO can poison slowly over a period of several hours, even in low concentrations. Sensitive organs, such as the brain, heart and lungs, suffer the most from a lack of oxygen.

High concentrations of carbon monoxide can kill in less than five minutes. At low concentrations, it will require a longer period of time to affect the body. Exceeding the EPA concentration of 9 parts per million (ppm) for more than eight hours may have adverse health affects. The limit of CO exposure for healthy workers, as prescribed by the U.S. Occupational Health and Safety Administration, is 50 ppm.

Potential Sources of Carbon Monoxide

Any fuel-burning appliances which are malfunctioning or improperly installed can be a source of CO, such as:

  • furnaces;
  • stoves and ovens;
  • water heaters;
  • dryers;
  • room and space heaters;
  • fireplaces and wood stoves;
  • charcoal grills;
  • automobiles;
  • clogged chimneys or flues;
  • space heaters;
  • power tools that run on fuel;
  • gas and charcoal grills;
  • certain types of swimming pool heaters; and
  • boat engines.

PPM   % CO
in air 
Health Effects in Healthy Adults  Source/Comments 
0 0% no effects; this is the normal level in a properly operating heating appliance  
35 0.0035% maximum allowable workplace exposure limit for an eight-hour work shift The National Institute for Occupational Safety and Health (NIOSH)
50 0.005% maximum allowable workplace exposure limit for an eight-hour work shift               OSHA
100 0.01% slight headache, fatigue, shortness of breath,
errors in judgment
125 0.0125%   workplace alarm must sound (OSHA)
200 0.02% headache, fatigue,
nausea, dizziness
400 0.04% severe headache, fatigue, nausea, dizziness, confusion; can be life-threatening after three hours of exposure evacuate area immediately
800 0.08% convulsions, loss of consciousness;
death within three hours
evacuate area immediately
12,000 1.2% nearly instant death

CO Detector Placement
CO detectors can monitor exposure levels, but do not place them:

  • directly above or beside fuel-burning appliances, as appliances may emit a small amount of carbon monoxide upon start-up;
  • within 15 feet of heating and cooking appliances, or in or near very humid areas, such as bathrooms;
  • within 5 feet of kitchen stoves and ovens, or near areas locations where household chemicals and bleach are stored (store such chemicals away from bathrooms and kitchens, whenever possible);
  • in garages, kitchens, furnace rooms, or in any extremely dusty, dirty, humid, or greasy areas;
  • in direct sunlight, or in areas subjected to temperature extremes. These include unconditioned crawlspaces, unfinished attics, un-insulated or poorly insulated ceilings, and porches;
  • in turbulent air near ceiling fans, heat vents, air conditioners, fresh-air returns, or open windows. Blowing air may prevent carbon monoxide from reaching the CO sensors.

Do place CO detectors:

  • within 10 feet of each bedroom door and near all sleeping areas, where it can wake sleepers. The Consumer Product Safety Commission (CPSC) and Underwriters Laboratories (UL) recommend that every home have at least one carbon monoxide detector for each floor of the home, and within hearing range of each sleeping area;
  • on every floor of your home, including the basement (source:  International Association of Fire Chiefs/IAFC);
  • near or over any attached garage. Carbon monoxide detectors are affected by excessive humidity and by close proximity to gas stoves (source:  City of New York);
  • near, but not directly above, combustion appliances, such as furnaces, water heaters, and fireplaces, and in the garage (source:  UL); and
  • on the ceiling in the same room as permanently installed fuel-burning appliances, and centrally located on every habitable level, and in every HVAC zone of the building (source:  National Fire Protection Association 720). This rule applies to commercial buildings.

In North America, some national, state and local municipalities require installation of CO detectors in new and existing homes, as well as commercial businesses, among them:  Illinois, Massachusetts, Minnesota, New Jersey, Vermont and New York City, and the Canadian province of Ontario. Installers are encouraged to check with their local municipality to determine what specific requirements have been enacted in their jurisdiction.

How can I prevent CO poisoning?

  • Purchase and install carbon monoxide detectors with labels showing that they meet the requirements of the new UL standard 2034 or Comprehensive Safety Analysis 6.19 safety standards.
  • Make sure appliances are installed and operated according to the manufacturer’s instructions and local building codes. Have the heating system professionally inspected by an InterNACHI inspector and serviced annually to ensure proper operation. The inspector should also check chimneys and flues for blockages, corrosion, partial and complete disconnections, and loose connections.
  • Never service fuel-burning appliances without the proper knowledge, skill and tools. Always refer to the owner’s manual when performing minor adjustments and when servicing fuel-burning equipment.
  • Never operate a portable generator or any other gasoline engine-powered tool either in or near an enclosed space, such as a garage, house or other building. Even with open doors and windows, these spaces can trap CO and allow it to quickly build to lethal levels.
  • Never use portable fuel-burning camping equipment inside a home, garage, vehicle or tent unless it is specifically designed for use in an enclosed space and provides instructions for safe use in an enclosed area.
  • Never burn charcoal inside a home, garage, vehicle or tent.
  • Never leave a car running in an attached garage, even with the garage door open.
  • Never use gas appliances, such as ranges, ovens or clothes dryers to heat your home.
  • Never operate un-vented fuel-burning appliances in any room where people are sleeping.
  • During home renovations, ensure that appliance vents and chimneys are not blocked by tarps or debris. Make sure appliances are in proper working order when renovations are complete.
  • Do not place generators in the garage or close to the home. People lose power in their homes and get so excited about using their gas-powered generator that they don’t pay attention to where it is placed. The owner’s manual should explain how far the generator should be from the home.
  • Clean the chimney. Open the hatch at the bottom of the chimney to remove the ashes.  Hire a chimney sweep annually.
  • Check vents. Regularly inspect your home’s external vents to ensure they are not obscured by debris, dirt or snow.

In summary, carbon monoxide is a dangerous poison that can be created by various household appliances. CO detectors must be placed strategically throughout the home or business in order to alert occupants of high levels of the gas.  This article is from InterNACHI and can be found at https://www.nachi.org/carbon-monoxide.htm.

Schedule your home inspection with Red Horse Home Inspection.  Follow us on Facebook and Instagram.

by Nick Gromicko, CMI®

Anti-scald valves, also known as tempering valves and mixing valves, mix cold water in with outgoing hot water so that the hot water that leaves a fixture is not hot enough to scald a person. Anti-scald valves are used to regulate water temperature in buildings

Facts and Figures

  • Scalds account for 20% of all burns.
  • More than 2,000 American children are scalded each year, mostly in the bathroom and kitchen.
  • Scalding and other types of burns require costly and expensive hospital stays, often involving skin grafts and plastic surgery.
  • Scalding may lead to additional injuries, such as falls and heart attacks, especially among the elderly.
  • Water that is 160º F can cause scalding in 0.5 seconds.

Unwanted temperature fluctuations are an annoyance and a safety hazard. When a toilet is flushed, for instance, cold water flows into the toilet’s tank and lowers the pressure in the cold-water pipes. If someone is taking a shower, they will suddenly feel the water become hotter as less cold water is available to the shower valve. By the same principle, the shower water will become colder when someone in the house uses the hot-water faucet. This condition is exacerbated by plumbing that’s clogged, narrow, or installed in showers equipped with low-flow or multiple showerheads. A sudden burst of hot water can cause serious burns, particularly in young children, who have thinner skin than adults. Also, a startling thermal shock – hot or cold – may cause a person to fall in the shower as he or she scrambles on the slippery surface to adjust the water temperature. The elderly and physically challenged are at particular risk.

Anti-scald valves mitigate this danger by maintaining water temperature at a safe level, even as pressures fluctuate in water supply lines. They look similar to ordinary shower and tub valves and are equipped with a special diaphragm or piston mechanism that immediately balances the pressure of the hot- and cold-water inputs, limiting one or the other to keep the temperature within a range of several degrees. As a side effect, the use of an anti-scald valve increases the amount of available hot water, as it is drawn more slowly from the water heater. Inspectors and homeowners may want to check with the authority having jurisdiction (AHJ) to see if these safety measures are required in new construction in their area.

Installation of anti-scald valves is typically simple and inexpensive. Most models are installed in the hot-water line and require a cold-water feed. They also require a swing check valve on the cold-water feed line to prevent hot water from entering the cold-water system. They may be installed at the water heater to safeguard the plumbing for the whole building, or only at specific fixtures.

The actual temperature of the water that comes out of the fixture may be somewhat different than the target temperature set on the anti-scald valve. Such irregularities may be due to long, uninsulated plumbing lines or defects in the valve itself. Users may fine-tune the valve with a rotating mechanism that will allow the water to become hotter or colder, depending on which way it’s turned. Homeowners may contact an InterNACHI inspector or a qualified plumber if they have further questions or concerns.

In summary, anti-scald valves are used to reduce water temperature fluctuations that may otherwise inconvenience or harm unsuspecting building occupants.  This article is from InterNACHI and can be found at https://www.nachi.org/anti-scald-valve.htm.

Schedule your home inspection with Red Horse Home Inspection.  Follow us on Facebook and Instagram.

by Nick Gromicko, CMI® and Kenton Shepard
Between approximately 1965 and 1973, single-strand (solid) aluminum wiring was sometimes substituted for copper branch-circuit wiring in residential electrical systemsAluminum and copper wiring, with each metal clearly identifiable by its color due to the sudden escalating price of copper. After a decade of use by homeowners and electricians, inherent weaknesses were discovered in the metal that lead to its disuse as a branch wiring material. Aluminum will become defective faster than copper due to certain qualities inherent in the metal. Neglected connections in outlets, switches and light fixtures containing aluminum wiring become increasingly dangerous over time. Poor connections cause wiring to overheat, creating a potential fire hazard. In addition, the presence of single-strand aluminum wiring may void a home’s insurance policies. Inspectors may instruct their clients to talk with their insurance agents about whether the presence of aluminum wiring in their home is a hazard, a defect, and a problem that requires changes to their policy language.
According to the InterNACHI Home Inspection Standards of Practice, a home inspector is required to report upon single-strand, solid conductor aluminum branch-circuit wiring, if observed by the home inspector.
Facts and Figures 
 
  • On April, 28, 1974, two people were killed in a house fire in Hampton Bays, New York. Fire officials determined that the fire was caused by a faulty aluminum wire connection at an outlet.
  • According to the Consumer Product Safety Commission (CPSC), “Homes wired with aluminum wire manufactured before 1972 [‘old technology’ aluminum wire] are 55 times more likely to have one or more connections reach “Fire Hazard Conditions” than is a home wired with copper.”
Aluminum as a Metal

Aluminum possesses certain qualities that, compared with copper, make it an undesirable material as an electrical conductor. These qualities all lead to loose connections, where fire hazards become likely. These qualities are as follows:

  • higher electrical resistance. Aluminum has a high resistance to electrical current flow, which means that, given the same amperage, aluminum conductors must be of a larger diameter than would be required by copper conductors.
  • less ductile. Aluminum will fatigue and break down more readily when subjected to bending and other forms of abuse than copper, which is more ductile. Fatigue will cause the wire to break down internally and will increasingly resist electrical current, leading to a buildup of excessive heat.
  • galvanic corrosion.  In the presence of moisture, aluminum will undergo galvanic corrosion when it comes into contact with certain dissimilar metals.
  • oxidation. Exposure to oxygen in the air causes deterioration to the outer surface of the wire. This process is called oxidation. Aluminum wire is more easily oxidized than copper wire, and the compound formed by this process – aluminum oxide – is less conductive than copper oxide. As time passes, oxidation can deteriorate connections and present a fire hazard.
  • greater malleability. Aluminum is soft and malleable, meaning it is highly sensitive to compression. After a screw has been over-tightened on aluminum wiring, for instance, the wire will continue to deform or “flow” even after the tightening has ceased. This deformation will create a loose connection and increase electrical resistance in that location.
  • greater thermal expansion and contraction. Even more than copper, aluminum expands and contracts with changes in temperature. Over time, this process will cause connections between the wire and the device to degrade. For this reason, aluminum wires should never be inserted into the “stab,” “bayonet” or “push-in” type terminations found on the back of many light switches and outlets.
  • excessive vibration. Electrical current vibrates as it passes through wiring. This vibration is more extreme in aluminum than it is in copper, and, as time passes, it can cause connections to loosen.

Identifying Aluminum Wiring

  • Aluminum wires are the color of aluminum and are easily discernible from copper and other metals.
  • Since the early 1970s, wiring-device binding terminals for use with aluminum wire have been marked CO/ALR, which stands for “copper/aluminum revised.”
  • Look for the word “aluminum” or the initials “AL” on the plastic wire jacket. Where wiring is visible, such as in the attic or electrical panel, inspectors can look for printed or embossed letters on the plastic wire jacket. Aluminum wire may have the word “aluminum,” or a specific brand name, such as “Kaiser Aluminum,” marked on the wire jacket. Where labels are hard to read, a light can be shined along the length of the wire.
  • When was the house built? Homes built or expanded between 1965 and 1973 are more likely to have aluminum wiring than houses built before or after those years.

Options for Correction

Aluminum wiring should be evaluated by a qualified electrician who is experienced in evaluating and correcting aluminum wiring problems. Not all licensed electricians are properly trained to deal with defective aluminum wiring. The CPSC recommends the following two methods for correction for aluminum wiring:

  • Rewire the home with copper wire. While this is the most effective method, rewiring is expensive and impractical, in most cases.
  • Use copalum crimps. The crimp connector repair consists of attaching a piece of copper wire to the existing aluminum wire branch circuit with a specially designed metal sleeve and powered crimping tool. This special connector can be properly installed only with the matching AMP tool. An insulating sleeve is placed around the crimp connector to complete the repair. Although effective, they are expensive (typically around $50 per outlet, switch or light fixture).

Although not recommended by the CPSC as methods of permanent repair for defective aluminum wiring, the following methods may be considered:

  • application of anti-oxidant paste. This method can be used for wires that are multi-stranded or wires that are too large to be effectively crimped.
  • pigtailing. This method involves attaching a short piece of copper wire to the aluminum wire with a twist-on connector. the copper wire is connected to the switch, wall outlet or other termination device. This method is only effective if the connections between the aluminum wires and the copper pigtails are extremely reliable. Pigtailing with some types of connectors, even though Underwriters Laboratories might presently list them for the application, can lead to increasing the hazard. Also, beware that pigtailing will increase the number of connections, all of which must be maintained. Aluminum Wiring Repair (AWR), Inc., of Aurora, Colorado, advises that pigtailing can be useful as a temporary repair or in isolated applications, such as the installation of a ceiling fan.
  • CO/ALR connections. According to the CPSC, these devices cannot be used for all parts of the wiring system, such as ceiling-mounted light fixtures or permanently wired appliances and, as such, CO/ALR connections cannot constitute a complete repair. Also, according to AWR, these connections often loosen over time.
  • alumiconn. Although AWR believes this method may be an effective temporary fix, they are wary that it has little history, and that they are larger than copper crimps and are often incorrectly applied.
  • Replace certain failure-prone types of devices and connections with others that are more compatible with aluminum wire.
  • Remove the ignitable materials from the vicinity of the connections.

In summary, aluminum wiring can be a fire hazard due to inherent qualities of the metal. Inspectors should be capable of identifying this type of wiring. This article in from InterNACHI and can be found athttps://www.nachi.org/aluminum-wiring.htm.

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Log homes may be site-built or pre-cut in a factory for delivery to the site. Some log home manufacturers can also customize their designs. Before designing or purchasing a manufactured log

home, you need to consider the following factors for energy efficiency.

The R-Value of Wood
In a log home, the wood helps provide some insulation. Wood’s thermal resistance (or resistance to heat flow) is measured by its R-value. The higher the R-value, the more thermal resistance.
The R-value for wood ranges between 1.41 per inch (2.54 cm) for most softwoods, and 0.71 for most hardwoods. Ignoring the benefits of the thermal mass, a 6-inch (15.24 cm) thick log wall would have a clear-wall (a wall without windows or doors) R-value of just over 8.

Compared to a conventional wood stud wall (31 D2 inches [8.89 cm] insulation, sheathing, wallboard, a total of about R-14), the log wall is apparently a vastly inferior insulation system. Based only on this, log walls do not satisfy most building codes’ energy standards. However, to what extent a log building interacts with its surroundings depends greatly on the climate. Because of the log’s heat-storage capability, its large mass may cause the walls to behave considerably better in some climates than in others. Logs act like “thermal batteries” and can, under the right circumstances, store heat during the day and gradually release it at night. This generally increases the apparent R-value of a log by 0.1 per inch of thickness in mild, sunny climates that have a substantial temperature swing from day to night. Such climates generally exist in the Earth’s temperate zones between the 15th and 40th parallels.

Minimizing Air Leakage in Log Homes
Log homes are susceptible to developing air leaks. Air-dried logs are still about 15% to 20% water when the house is assembled or constructed. As the logs dry over the next few years, the logs shrink. The contraction and expansion of the logs open gaps between the logs, creating air leaks, which cause drafts and high heating requirements. To minimize air leakage, logs should be seasoned (dried in a protected space) for at least six months before construction begins. These are the best woods to use to avoid this problem, in order of effectiveness:

  • cedar;
  • spruce;
  • pine;
  • fir; and
  • larch.

Since most manufacturers and experienced builders know of these shrinkage and resulting air leakage problems, many will kiln-dry the logs prior to finish-shaping and installation. Some also recommend using plastic gaskets and caulking compounds to seal gaps. These seals require regular inspection and re-sealing when necessary. To be safe, always hire an InterNACHI inspector.

Controlling Moisture in Log Homes
Since trees absorb large amounts of water as they grow, the tree cells are also able to absorb water very readily after the wood has dried. For this reason, a log home is very hydroscopic—it can absorb water quickly. This promotes wood rot and insect infestation. It is strongly recommended that you protect the logs from any contact with any water or moisture. One moisture-control method is to use only waterproofed and insecticide-treated logs. Re-apply these treatments every few years for the life of the house. Generous roof overhangs, properly sized gutters and downspouts, and drainage plains around the house are also critical for moisture control.
Building Energy-Code Compliance for Log Homes
Because log homes don’t have conventional wood-stud walls and insulation, they often don’t satisfy most building codes’ energy standards—usually those involving required insulation R-values. However, several states—including Pennsylvania, Maine and South Carolina—have exempted log-walled homes from normal energy compliance regulations. Others states, such as Washington, have approved “prescriptive packages” for various sizes of logs, but these may or may not make sense in terms of energy efficiency. The American Society of Heating, Refrigerating and Air-Conditioning Engineers’ (ASHRAE) 90.2 standard contains a thermal mass provision that may make it easier to get approval in those states that base their codes on this standard. To find out the log building code standards for your state, contact your city or county building code officials. Your state energy office may be able to provide information on energy codes recommended or enforced in your state.
Building and Restoration of Log Cabins
 
Foundation 
The foundation of a log cabin is made of stone pillars. The stones provide a sturdy base to support the cabin and act as a barrier between the cabin and the earth. The stones may settle over time, and the foundation is carefully examined for damage and wear, and subsequently repaired during restoration.
Wall Construction
 

 The walls are made of logs, placed either vertically or horizontally, depending on the style and size of the cabin. The logs are notched at the corners to allow them to fit together. Corner-notching is a notable characteristic of log cabin construction because it provides stability by locking the log ends in place, enabling the logs to fit together in a secure manner. Many different methods of corner-notching exist, ranging from simple “saddle”-notching, to the common “V”-notching or “steeple”- notching, which get their name from the shape of the notch cut into the wood. These notching methods are marked by a cut into the wood that allows another cut piece of wood to fit together like a puzzle piece. Another commonly used technique, “square”-notching, differs in that the logs are secured with the addition of pegs or spikes.

The number of logs used per wall varies with the size of the cabin. The spaces between the logs are usually filled with a combination of materials in a process known as “chinking” and “daubing.” This process seals the exterior walls, protecting them from weather and animal damage.

Roof
Log cabin roofs are often gabled and are comprised of hand-split wood shingles. The roofs often develop damage and leaks over the years and are commonly included in restoration.
Doors
Many log cabins have both front and rear doors. Due to the many times the doors are opened and closed over the years, the doors are often not in good working order and require repair during restoration. Both doors on the cabin can be comprised of hand-dressed boards which open inward and are fastened to the log structure with pegs.
Windows
Most cabins feature two windows, located on either side of the chimney. The windows hold glass panes, which most likely will need to be replaced during the restoration of the cabin.
Chimney
The cabin generally has a chimney.  A common problem is that it will sink and deteriorate into many different pieces over the years. 

 

Glossary of Terms:
  • butt joints:  occur when two logs are placed end-to-end.
  • checking:  the natural cracking of logs as they shrink.
  • chinking:  the mixture used to fill the gaps between logs; can be natural materials or synthetic.
  • handcrafted log home:  a
  • home that is constructed of logs that are individually fit together.
  • insulated log home:  constructed with half-logs attached to a standard 2×6 frame structure.
  • log course:  one layer of logs placed atop the entire foundation of the home.
  • milled log home:  constructed of machine-lathed logs, and is also used to describe a log home built from a kit.
  • settlement:  the downward movement of log courses as the logs shrink.
  • shrinking:  the normal loss of diameter in logs as they lose moisture.

Inspecting a Log Home

Log Wall Exterior
The inspector shall inspect exterior surfaces of log walls, when such surfaces are visible, looking for:
  • the presence of mold, mildew or fungus;
  • cracks located at tops of logs and facing up;
  • discoloration, graying, bleaching or staining of logs;
  • loose or missing caulking;
  • separation of joints;
  • the condition of chinking, to include cracking, tears, holes or separation of log courses; and
  • the condition of log ends.
Other Exterior Concerns
In addition to the items specified in InterNACHI Standards of Practice 2.1 and 2.2, the inspector shall inspect:

  • downspout extensions;
  • grading and water flow away from log walls; and
  • vertical support posts under and on all porches.
Log Wall Interior
The inspector shall inspect interior surfaces of log walls, when such surfaces are visible, looking for:
  • separation between logs, including light or air penetration from outdoors;
  • separation between exterior log wall and interior partition walls; and
  • separation between log walls and interior ceilings.
Other Interior Concerns
In addition to the items specified in InterNACHI Standards of Practice 2.4 and 2.6, the inspector shall inspect:
  • dlip joints, adjustable sleeves, looped water supply lines, flexible hose sections, and flexible ductwork that are visible as part of the standard heating and plumbing inspections.
Exclusions
The inspector is not required to:
  • inspect or predict the condition of the interiors of logs.
  • predict the life expectancy of logs.
  • climb onto log walls. However, the inspector may inspect log walls by use of a ladder, if this procedure may be done safely and without damaging the walls.
  • inspect components of the porch support system, or of the plumbing or heating systems, that are not readily visible and accessible.
  • This article is from InterNACHI and can be found at https://www.nachi.org/loghomes.htm.
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by Nick Gromicko, CMI®

 
A room must conform to specific requirements in order for it to be considered a bedroom or sleeping room. The reason for this law is that the inhabitant must be able to quickly escape in case of fire or another emergency.

Why would a homeowner use a non-conforming room as a bedroom?Non-conforming window  Some of the reasons include:
  • to earn money from it as a rental. While they run the risk of being discovered by the city, landlords will profit by renting out rooms that are not legally bedrooms;
  • to increase the value of the home. All other considerations being equal, a four-bedroom house will usually sell for more than a three-bedroom house; and
  • lack of knowledge of code requirements. To the untrained eye, there is little obvious difference between a conforming bedroom and non-conforming bedroom. When an emergency happens, however, the difference will be more apparent. If you have any questions about safety requirements, ask your InterNACHI inspector during your next scheduled inspection.

Homeowners run serious risks when they use a non-conforming room as a bedroom. An embittered tenant, for instance, may bring their landlord to court, especially if the tenant was forced out when the faux bedroom was exposed. The landlord, upon being exposed, might choose to adjust the bedroom to make it code-compliant, but this can cost thousands of dollars. Landlords can also be sued if they sell the home after having advertised it as having more bedrooms than it actually has. And the owner might pay more than they should be paying in property tax if they incorrectly list a non-conforming bedroom as a bedroom. Perhaps the greatest risk posed by rooms that unlawfully serve as bedrooms stems from the reason these laws exist in the first place:  rooms lacking egress can be deadly in case of an emergency. For instance, on January 5, 2002, four family members sleeping in the basement of a Gaithersburg, Maryland, townhome were killed by a blaze when they had no easy escape.

The following requirements are taken from the 2006 International Residential Code (IRC), and they can be used as a general guide, but bear in mind that the local municipality determines the legal definition of a bedroom. Such local regulations can vary widely among municipalities, and what qualifies as a bedroom in one city might be more properly called a den in a nearby city. In some municipalities, the room must be above grade, be equipped with an AFCI or smoke alarm to be considered a conforming bedroom, for instance. Ceiling height and natural lighting might also be factors. The issue can be extremely complex, so it’s best to learn the code requirements for your area. Nevertheless, the IRC can be useful, and it reads as follows:

  • EMERGENCY ESCAPE AND RESCUE REQUIRED SECTION: R 310.1 Basements and every sleeping room shall have at least one operable emergency and rescue opening. Such opening shall open directly into a public street, public alley, yard or court. Where basements contain one or more sleeping rooms, emergency egress and rescue openings shall be required in each sleeping room, but shall not be required in adjoining areas of the basement. Where emergency escape and rescue openings are provided, they shall have a sill height of not more than 44 inches (1,118mm) above the floor. Where a door opening having a threshold below the adjacent ground elevation serves as an emergency escape and rescue opening and is provided with a bulkhead enclosure, the bulkhead enclosure shall comply with SECTION R310.3. The net clear opening dimensions required by this section shall be obtained by the normal operation of the emergency escape and rescue opening from the inside. Emergency escape and rescue openings with a finished sill height below the adjacent ground elevation shall be provided with a window well, in accordance with SECTION R310.2.  
    • MINIMUM OPENING AREA: SECTION: R 310.1.1 All emergency escape and rescue openings shall have a minimum net clear opening of 5.7 square feet (0.530 m2). Exception: Grade floor openings shall have a minimum net clear opening of 5 square feet (0.465 m2).
    • MINIMUM OPENING HEIGHT: R 310.1.2 The minimum net clear opening height shall be 24 inches (610mm).
    • MINIMUM OPENING WIDTH: R 310.1.3 The minimum net clear opening width shall be 20 inches (508mm).
    • OPERATIONAL CONSTRAINTS: R 310.1.4 Emergency escape and rescue openings shall be operational from the inside of the room without the use of keys or tools or special knowledge.

  • WINDOW WELLS: SECTION: R310.2 The minimum horizontal area of the window well shall be 9 square feet (0.9 m2), with a minimum horizontal projection and width of 36 inches (914mm). The area of the window well shall allow the emergency escape and rescue opening to be fully opened. Exception: The ladder or steps required by SECTION R 310.2.1 shall be permitted to encroach a maximum of 6 inches (152mm) into the required dimensions of the window well.
  • LADDER AND STEPS: SECTION: R 310.2.1 Window wells with a vertical depth greater than 44 inches (1,118mm) shall be equipped with a permanently affixed ladder or steps usable with the window in the fully open position. Ladders or steps required by this section shall not be required to comply with SECTIONS R311.5 and R311.6. Ladders or rungs shall have an inside width of at least 12 inches (305 mm), shall project at least 3 inches (76mm) from the wall, and shall be spaced not more than 18 inches (457mm) on-center vertically for the full height of the window well.
  • BULKHEAD ENCLOSURES: SECTION: R 310.3 Bulkhead enclosures shall provide direct access to the basement. The bulkhead enclosure with the door panels in the fully open position shall provide the minimum net clear opening required by SECTION R 310.1.1. Bulkhead enclosures shall also comply with SECTION R 311.5.8.2.
  • BARS, GRILLS, COVERS, AND SCREENS: SECTION: R 310.3 Bars, grilles, covers, screens or similar devices are permitted to be placed over emergency escape and rescue openings, bulkhead enclosures, or window wells that serve such openings, provided the minimum net clear opening size complies with SECTIONS R 310.1.1 to R 310.1.3, and such devices shall be releasable or removable from the inside without the use of a key, tool, special knowledge, or force greater than that which is required for normal operation of the escape and rescue opening.
  • EMERGENCY ESCAPE WINDOWS UNDER DECKS AND PORCHES: SECTION: R 310.5 Emergency escape windows are allowed to be installed under decks and porches, provided the location of the deck allows the emergency escape window to be fully opened and provides a path not less than 36 inches (914 mm) in height to a yard or court.
In summary, non-conforming bedrooms are rooms that unlawfully serve as bedrooms, as the occupant would lack an easy escape in case of emergency.  This article is from InterNACHI and can be found at
https://www.nachi.org/non-conforming-bedrooms.htm.
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by Nick Gromicko, CMI®

There was a time when the only remedy for sinking sidewalks or uneven foundations was to tear out the old pavement slab and pour a new one, and spend a great deal of time and money in the process. Today, a less intensive alternative known as mudjacking (also called concrete leveling, pressure grouting or slabjacking) pumps A sunken concrete sidewalk in desperate need of repairslurry beneath a sunken concrete slab in order to raise it back into place.

Concrete sinks because its underlying support, for various reasons, gives way. The original concrete may have been installed on dirt that hadn’t been compacted sufficiently, for instance, or soil erosion may be responsible. And some soil simply settles naturally over many years. Regardless of the cause, sunken concrete can lead to many structural defects, including failed retaining walls, foundation settling, uneven junctions of concrete, sunken sidewalks, uneven concrete pads, cracked foundations, and bowed basement walls. If left uncorrected, these defects can lead to unwanted water runoff and major structural problems.
And, aside from the shabby appearance and decreased functionality of an uneven sidewalk, steps or walkway, sunken concrete can create major trip hazards for which the building owner is liable. If a building owner notices any of these conditions, they should consult with their InterNACHI inspector during their next scheduled inspection.

Process
First, small holes are drilled into the concrete, through which is pumped a slurry that may be composed of various materials, such as sand, cement, soil, limestone, bentonite clay, water or expanding polymers. The particular mixture is based on the type of application and the mudjacker’s preference. The slurry then fills any gaps and forces the concrete to rise back into place before the drilled holes are plugged up with cement, leaving the only visible evidence of the repair. Over the next day, the slurry solidifies and stabilizes the subsoil, making further sinking unlikely.

While this is not a complicated procedure, it should be performed only by a trained professional, as amateur workmanship may cause even more extensive damage. Drain pipes, sewers and utilities must be located and avoided, and the area must be evaluated as to whether it can survive the mudjacking process.

Some advantages of mudjacking over re-pouring cement include:The only evidence left of mudjacking is the patched hole through which the slurry was pumped. Photo produced by InterNACHI member Mike Morgan.
  • efficiency. Mudjacking requires less equipment and fewer workers. Adjacent plants and landscaping are also disturbed less, as are neighbors, tenants and passersby by the loud noise, dust and cumbersome equipment;
  • price. Mudjacking typically costs roughly half as much as concrete replacement because there is little need for new cement or the removal of old concrete. The overall cost is based on the area of concrete that must be lifted, which may be as little as $5 per foot. Thus, for a 5×4-foot job, it might cost just $60, although the mudjacker may charge more if the area is in a hard-to-reach location;
  • speed. Mudjacking takes hours, while certain concrete pours may take days; and
  • environmentally friendly. Mudjacking makes use of perfectly good concrete, which would otherwise be sent to a landfill.
Limitations of Mudjacking
Mudjacking may be an ineffective waste of resources in the following situations:
  • The concrete surface is spalling or otherwise damaged. The mudjacking process might further damage the surface, which will still be defective even after it’s raised back into place.
  • The concrete has risen, caused by expansive soil. The only solution for this defect is to re-pour the cement.
  • The cause of the settling is not addressed. If the soil has settled due to some external factor, the problem must be fixed or the soil will sink again in the future. For instance, a gutter downspout that drains onto a concrete edge must be corrected in order to avoid the need for future repair.
  • The underlying soil is swampy.
  • There is a sinkhole beneath the concrete.
In summary, mudjacking is an inexpensive, fast and clean way to level a sunken concrete slab. This article is from InterNACHI and can be found at https://www.nachi.org/mudjacking.htm.
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