Home Inspection FYI

Providing Help, Knowledge and Other Useful Information To Home Owners Everywhere

Home Inspection FYI - Providing Help, Knowledge and Other Useful Information To Home Owners Everywhere

Tag Archives: mold growth

Mold Spores, Mold Growth and Testing Measures

Mold spore and mold growth from water damage and moisture are common. Mold inspections and other testing can help find these problems.

Taking air samples during a mold inspection is important for several reasons.  Mold spores are not visible to the naked eye, and the types of mold present can often be determin
air sample mold Mold Spores, Mold Growth and Testing Measuresed through laboratory analysis of the air samples.  Having samples analyzed can also help provide evidence of the scope and severity of a mold problem, as well as aid in assessing human exposure to mold spores.  After remediation, new samples are typically taken to help ensure that all mold has been successfully removed.

Air samples can be used to gather data about mold spores present in the interior of a house.  These samples are taken by using a pump that forces air through a collection device which catches mold spores.  The sample is then sent off to a laboratory to be analyzed.  InterNACHI inspectors who perform mold inspections often utilize air sampling to collect data, which has become commonplace.

Air-Sampling Devices For Mold Testing and Mold Exposure

There are several types of devices used to collect air samples that can be analyzed for mold exposure.  Some common examples include:

  • impaction samplers that use a calibrated air pump to impact spores onto a prepared microscope slide;
  • cassette samplers, which may be of the disposable or one-time-use type, and also employ forced air to impact spores onto a collection media; and
  • airborne-particle collectors that trap spores directly on a culture dish.  These may be utilized to identify the species of mold that has been found.

When to Test and Gather Air Samples for Mold Exposure

Samples are generally best taken if visual, non-invasive examination reveals apparent mold growth or conditions that could lead to growth, such as moisture intrusion or water damage.  Musty odors can also be a sign of mold growth.  If no sign of water damage or mold or potential for mold exposure is apparent, one or two indoor air samples can still be taken, at the discretion of the inspector and client, in the most lived-in room of the house and at the HVAC unit.

Outdoor air samples are also typically taken as a control for comparison to indoor samples.  Two samples — one from the windward side and one from the leeward side of the house — will help provide a more complete picture of what is in the air that may be entering the house through windows and doors at times when they are open.  It is best to take the outdoor samples as close together in time as possible to the indoor samples that they will be compared with.

InterNACHI inspectors should avoid taking samples if a resident of the house is under a physician’s care for mold exposure, if there is litigation in progress related to mold on the premises, or if the inspector’s health or safety could be compromised in obtaining the sample.  Residential home inspectors also should not take samples in a commercial or public building.

Water Damage and Where to Sample For Mold Growth and Ideal Conditions 

In any areas of a house suspected or confirmed to have mold growth, air samples can be taken to help verify and gather more information.  Moisture intrusion, water damage, musty odors, apparent mold growth, or conditions conducive to mold growth are all common reasons to gather an air sample.  Samples should be taken near the center of the room, with the collection device positioned 3 to 6 feet off the ground. environmental air quality testing equipment Mold Spores, Mold Growth and Testing Measures

Ten minutes is an adequate amount of time for the air pump to run while taking samples, but this can be reduced to around five minutes if there is a concern that air movement from a lot of indoor activity could alter the results.  The sampling time can be reduced further if there is an active source of dust, such as from ongoing construction.

Sampling should take place in livable spaces within the house under closed conditions in order to help stabilize the air and allow for reproducibility of the sampling and measurement.  While the sample is being collected, windows and exterior doors should be kept shut other than for normal entry and exit from the home.  It is best to have air exchangers (other than a furnace) or fans that exchange indoor-outdoor air switched off during sampling.

Weather conditions can be an important factor in gathering accurate data. Severe thunderstorms or unusually high winds can affect the sampling and analysis results.  High winds or rapid changes in barometric pressure increase the difference in air pressure between the interior and exterior, which can increase the variability of airborne mold-spore concentration.  Large differences in air pressure between the interior and exterior can cause more airborne spores to be sucked inside, skewing the results of the sample.

Difficulties and Practicality of Air Sampling For Mold Spores

It is helpful to think of air sampling as just one tool in the tool belt when inspecting a house for mold problems.  An air sample alone is not enough to confirm or refute the existence of a problem, and such testing needs to be accompanied by visual inspection and other methods of data collection, such as a surface sample.  Indoor airborne spore levels can vary according to several factors, and this can lead to skewed results if care is not taken to set up the sampling correctly.  Also, since only spores are collected with an air sample and may actually be damaged during collection, identification of the mold type can be more difficult than with a sample collected with tape or a cultured sample. spore chain Mold Spores, Mold Growth and Testing Measures

Air samples are good for use as a background screen to ensure that there isn’t a large source of mold not yet found somewhere in a home.  This is because they can detect long chains of spores that are still intact.  These chains normally break apart quickly as they travel through the air, so a sample that reveals intact chains can indicate that there is mold nearby, possibly undiscovered during other tests and visual examination.

When taken under controlled conditions and properly analyzed, air samples for mold exposure, mold spores and mold growth are helpful in comparing relative particle levels between a problem such as water damage and a control area.  They can also be crucial for comparing particle levels and air quality in an area before and after mold remediation.

Mold Info

tumblr Mold Spores, Mold Growth and Testing Measuresstumbleupon Mold Spores, Mold Growth and Testing Measuresdelicious Mold Spores, Mold Growth and Testing Measuresdigg Mold Spores, Mold Growth and Testing Measures

Sauna FYI

Sauna Information and Facts

A sauna is a small, sealed room, typically constructed of wood, designed to safely increase the user’s body temperature through a combination of heat and well-controlled humidity. Saunas are used recreationally and therapeutically, as users find them relaxing and health-promoting.girls in sauna 300x222 Sauna FYI

Sauna Facts and Figures

  • “Sauna” is the only Finnish word in the English dictionary. Traditionally, the Finns used the sauna as a place to clear the mind, give birth, and prepare the dead for burial. They were not used for weight loss or as part of an exercise regimen, which are newer concepts for their use today.
  • Saunas can be divided into two basic styles:
    • infrared saunas directly warm occupants and other objects (much like the sun) using charcoal or other objects; and
    • conventional saunas heat the room indirectly by warming the air.
  • One of the earliest sauna designs is the smoke sauna, in which stones warm the room after being heated by a fire, which is extinguished before the room is ready for bathers. The smoke is vented from the sauna but its aroma lingers. The concept was nearly abandoned but has seen a revival over the past few decades.

Sauna Safety Tips

  • Saunas stimulate the cardiovascular system and should not be used by anyone with high blood pressure, diabetes, heart disease, or while under the use of antibiotics or other drugs. Never stay in a sauna longer than 30 minutes. While it may be fun to see who can stay in the sauna the longest, this sort of game is extremely dangerous and has led to injury and even death.  One experienced sauna devotee died in a sauna competition in August 2010.
  • Never wear jewelry in the sauna, as the metal and stones may heat up and burn exposed skin.
  • Use a towel as a barrier between yourself and the seat in a public commercial sauna to protect yourself against disease. Strains of antibiotic-resistant bacteria, known collectively as methicillin-resistant Staphylococcus aureus, have been shown to inhabit excessively humid and poorly cleaned public saunas and steam rooms. Reducing the humidity can also control the risk of transmission.
  • Children should not use saunas because they have trouble thermo-regulating to stave off hyperthermia.

Recommended Sauna Design Features

Adequate ventilation is perhaps the most overlooked sauna design feature. Outgoing ventilation expels stale air and reduces humidity-spawned mildew and moisture, which can cause wood decay. Incoming ventilation brings in fresh air, ensuring the safety and comfort of the users. Saunas typically have a vent behind the stove and another on the opposite wall near the ceiling. While the sauna may vent to the outside of the building, this is not required in residential saunas, and many systems utilize interior ventilation to heat the adjacent living space.

Some other essential design features include the following:

  • Freestanding saunas must have a solid foundation.
  • Sauna doors should be sealed and insulated.
  • The sauna door should swing outward and should not be equipped with a latching mechanism. If the user is in distress, he should be able to easily push his way out of the sauna.
  • Saunas should be constructed from a decay-resistant species of tree, such as cypress, redwood, spruce, cedar or Douglas fir.
  • Any electrical wiring should be moisture-proof and able to resist high temperatures.
  • Metal, especially screw heads, should not be exposed where people sit, lean or walk. Metal will get excessively hot and could burn exposed skin.
  • The ceiling height should be between 6½ to 7½ feet, but not higher, as heat will uselessly pool above the user’s head. Also, undue stress will be placed on the heater, which will be forced to work harder to heat the room.
  • The temperature should not exceed 195º F, as recommended by Underwriters Laboratories. Saunas heated by wood-burning stoves may be capable of exceeding this temperature, but this is not advisable, as it can endanger the users’ safety. Saunas that utilize excessive amounts of steam should be set to a lower temperature, as wet heat can cause scalding.
  • The floor can be made from concrete, vinyl or tile, but not carpet, which will deteriorate from the heat and humidity and create moisture-caused health hazards. Carpet is also a fire hazard.
  • To best utilize the space and to achieve a balanced temperature throughout the sauna, the shape of the sauna room should be nearly square.
  • The sauna should be regularly inspected for mildew and wood decay around its exterior.

 

Saunas are sealed, heated rooms used for therapeutic purposes and relaxation, but must be used and maintained properly to ensure the health and safety of their users.

 

Sauna Society

tumblr Sauna FYIstumbleupon Sauna FYIdelicious Sauna FYIdigg Sauna FYI

Moisture Intrusion

basementwall 300x229 Moisture IntrusionMoisture Intrusion


Moisture intrusion can be the cause of building defects, as well as health ailments for the building’s occupants. We should have at least a basic understanding of how moisture may enter a building, and where moisture problem areas commonly occur.

Some common moisture-related problems include:

  • structural wood decay;
  • high indoor humidity and resulting condensation;
  • expansive soil, which may crack the foundation through changes in volume, or softened soil, which may lose its ability to support an overlying structure;
  • undermined foundations;
  • metal corrosion;
  • ice dams; and
  • mold growth.  Mold can only grow in the presence of high levels of moisture. People who suffer from the following conditions can be seriously (even fatally) harmed if exposed to elevated levels of airborne mold spores:
    • asthma;
    • allergies;
    • lung disease; and/or
    • compromised immune systems.

Note:  People who do not suffer from these ailments may still be harmed by elevated levels of airborne mold spores.

How does moisture get into the house?

Moisture or water vapor moves into a house in the following ways:

  • air infiltration. Air movement accounts for more than 98% of all water vapor movement in building cavities. Air naturally moves from high-pressure areas to lower ones by the easiest path possible, such as a hole or crack in the building envelope. Moisture transfer by air currents is very fast (in the range of several hundred cubic feet of air per minute). Replacement air will infiltrate through the building envelope unless unintended air paths are carefully and permanently sealed;
  • by diffusion through building material. Most building materials slow moisture diffusion, to a large degree, although they never stop it completely;
  • leaks from roof;
  • plumbing leaks;
  • flooding, which can be caused by seepage from runoff or rising groundwater; it may be seasonal or catastrophic; and
  • human activities, including bathing, cooking, dishwashing and washing clothes. Indoor plants, too, may be a significant source of high levels of humidity.

Climate Zones and Moisture

In the northern U.S., moisture vapor problems are driven primarily by high indoor relative humidity levels, combined with low outdoor temperatures during the winter. In the southern U.S. (especially the southeast), the problem is largely driven by high outdoor humidity and low indoor temperatures during summer months. Mixed climates are exposed to both conditions and can experience both types of problems. Humid climates, in general, will be more of a moisture problem than dry climates. Wind-driven rain is the main cause of leaks and moisture through the building envelope.

Check for moisture intrusion in the following areas:

Moisture at Roofs

A roof leak may lead to the growth of visible mold colonies in the attic that can grow unnoticed. Roof penetrations increase the likelihood of water leaks due to failed gaskets, sealants and flashing. The number of roof penetrations may be reduced by a variety of technologies and strategies, including:

  • consolidation of vent stacks below the roof;
  • exhaust fan caps routed through walls instead of the roof;
  • high-efficiency combustion appliances, which can be sidewall-vented;
  • electrically powered HVAC equipment and hot water heaters that do not require flue; and
  • adequate flashing. Oftentimes, inspectors discover missing, incorrectly installed or corroded flashing pipes which contribute to moisture intrusion.

Moisture Intrusion From Plumbing

  • Distribution pipes and plumbing fixtures can be the source of large amounts of moisture intrusion. If the wall is moist and/or discolored, then moisture damage is already in progress. Most plumbing is hidden in the walls, so serious problems can begin unnoticed.
  • One of the most important means of moisture management in the bathroom is the exhaust fan. A non-functioning exhaust fan overloads the bathroom with damp air. If the exhaust fan doesn’t turn on automatically when the bathroom is in use, consider recommending switching the wiring or switch. The lack of an exhaust fan should be called out in the inspection report. The fan should vent into the exterior, not into the attic.
  • The bathroom sink, in particular, is a common source of moisture intrusion and damage. Although overflow drains can prevent the spillage of water onto the floor, they can become corroded and allow water to enter the cabinet.
  • Use a moisture meter to check for elevated moisture levels in the sub-floor around the toilet and tub.
  • Bathroom windows need to perform properly in a wide range of humidity and temperature conditions. Check to see if there are any obvious breaks in the weatherstripping and seals. Are there are stains or flaking on the painted surfaces?
  • Check showers and bathtubs. Is the caulking is cracked, stiff or loose in spots? Are there cracked tiles or missing grout that may channel water to vulnerable areas? If some water remains in the bathtub after draining, it may be a warning sign of possible structural weakening and settlement in the floor beneath the tub.

Moisture in The Utility Room

  • The water heater tank should be clean and rust-free.
  • The area around the water softener tank should be clean and dry.
  • Check that all through-the-wall penetrations for fuel lines, ducts, and electrical systems of heating system are well-sealed. All ducts should be clean and dust-free. Inspect the air supply registers in the house for dust accumulation.
  • Filters, supply lines, exterior wall penetrations, vents, ductwork and drainage of the cooling system must all be in good working order to avoid moisture problems.

Attic Moisture

  • Look for stains or discolorations at all roof penetrations. Chimneys, plumbing vents and skylight wells are common places where moisture may pass through the roof. Any such locations must be inspected for wetness, a musty smell and/or visible signs of mold.
  • Are there areas of the insulation that appear unusually thin?
  • Rust or corrosion around recessed lights are signs of a potential electrical hazard.

Foundations

Model building codes typically require damp-proofing of foundation walls. The damp-proofing shall be applied from the top of the footing to the finished grade. Parging of foundation walls should be damp-proofed in one of the following ways:

  • bituminous coating;
  • 3 pounds per square yard of acrylic modified cement;
  • 1/8-inch coat of surface-bonding cement; or
  • any material permitted for water-proofing.

In summary, moisture can enter a building in a number of different ways. High levels of moisture can cause building defects and health ailments.

Thanks to Nick Gromicko, Rob London and Kenton Shepard
tumblr Moisture Intrusionstumbleupon Moisture Intrusiondelicious Moisture Intrusiondigg Moisture Intrusion