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Frequently Asked Questions

Guardian Home Inspections is based in Fairfax, VA. We provide service to Fairfax, Arlington, Alexandria, Loudoun, Prince William, Fauquier, Montgomery VA, and Washington DC. We have multiple inspectors to help with your needs. Call Now to set up your appointment!

How do I find a home inspector?
The best source is a friend, or perhaps a business acquaintance, who has been satisfied with and can recommend a home inspector they have used. In addition, the names of local inspectors can be found by searching our online database, or in the Yellow Pages where many advertise under "Building Inspection Service" or "Home Inspection Service". Real estate agents are also generally familiar with the service, and should be able to provide you with a list of names from which to choose. Whatever your referral source, you will want to make sure that the home inspector is a Member of the American Society of Home Inspectors® (ASHI®) in order to be certain of his or her professional qualifications, experience, and business ethics. A list of ASHI® Members in your area is available upon request from the Association's headquarters.
What will the inspection cover?

A thorough Inspection covers everything from roof to the foundation.

How long will the Inspection take?

Most Inspections take about three to four hours. These times may vary depending on the size, age & condition of the home.

Should I be present during the Inspection?

We recommend that you be present at the site of the inspection, from start to finish.

Why use our Services?

The purchase of a new home is one of the single most costly investments that a family will make. Along with the extra stresses this will add, there is also the fear factor of, "Will This Home Stand The Test of Time?" It is also important to know what YOU, as the primary investor, are getting for your money.

A home inspection is an excellent tool for you, the home buyer, to help determine not only the condition of the home, but to also help foresee any immediate unnecessary additional cost that may go unnoticed without the help of a home inspection. Home inspections are not a prediction of future performance, but can pinpoint existing problem areas.

Why can't I have someone in my family who is very handy or a contractor, inspect my new home?

This is the biggest mistake many potential new homeowners make when purchasing a home. Although the person you are considering may be very skilled, they are not trained or experienced at professional home inspections. Professional home inspection is a unique skill like no other. Professional inspectors get what we call an inspector's instinct for problems. That instinct takes extensive training and lots of experience doing inspections to develop. Many contractors, and other trades professionals hire a professional home inspector to inspect their homes when they make a purchase.

A home inspection is an excellent tool for you, the home buyer, to help determine not only the condition of the home, but to also help foresee any immediate unnecessary additional cost that may go unnoticed without the help of a home inspection. Home inspections are not a prediction of future performance, but can pinpoint existing problem areas.

What if I have questions after the inspection?

You can call us and discuss all the aspects of your new home whenever you like. Our service is a long-term investment.

protect your system & investment

Wells Information

Properly constructed private water supply systems require little routine maintenance. These simple steps will help protect your system and investment.

  • Always use licensed or certified water well drillers and pump installers when a well is constructed, a pump is installed or the system is serviced.
  • An annual well maintenance check, including a bacterial test, is recommended. Any source of drinking water should be checked any time there is a change in taste, odor or appearance, or anytime a water supply system is serviced.
  • Keep hazardous chemicals, such as paint, fertilizer, pesticides, and motor oil far away from your well.
  • Periodically check the well cover or well cap on top of the casing (well) to ensure it is in good repair.
  • Always maintain proper separation between your well and buildings, waste systems or chemical storage facilities. Your professional contractor knows the rules.
  • Don't allow back-siphonage. When mixing pesticides, fertilizers or other chemicals, don't put the hose inside the tank or container.
  • When landscaping, keep the top of your well at least one foot above the ground. Slope the ground away from your well for proper drainage.
  • Take care in working or mowing around your well. A damaged casing could jeopardize the sanitary protection of your well. Don't pile snow, leaves, or other materials around your well.
  • Keep your well records in a safe place. These include the construction report, as well as annual water well system maintenance and water testing results.
  • Be aware of changes in your well, the area around your well, or the water it provides.
  • When your well has come to the end of its serviceable life (usually more than 20 years), have your qualified water well contractor properly decommission your well after constructing your new system.

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Septic Tank

Everything that goes down any of the drains in the house (toilets, showers, sinks, laundry machines) travels first to the septic tank. The septic tank is a large-volume, watertight tank which provides initial treatment of the household wastewater by intercepting solids and settleable organic matter before disposal of the wastewater (effluent) to the drain field.


While relatively simple in construction and operation, the septic tank provides a number of important functions through a complex interaction of physical and biological processes. The essential functions of the septic tank are to: receive all wastewater from the house separate solids from the wastewater flow cause reduction and decomposition of accumulated solids provide storage for the separated solids (sludge and scum) pass the clarified wastewater (effluent) out to the drain field for final treatment and disposal.

Primary Treatment
As stated, the main function of the septic tank is to remove solids from the wastewater and provide a clarified effluent for disposal to the drain field. The septic tank provides a relatively quiescent body of water where the
wastewater is retained long enough to let the solids separate by both
settling and flotation. This process is often called primary treatment and
results in three products: scum, sludge, and effluent.

Scum: Substances lighter than water (oil, grease, fats) float to the top,
where they form a scum layer. This scum layer floats on top of the water
surface in the tank. Aerobic bacteria work at digesting floating solids.

Sludge: The "sinkable" solids (soil, grit, bones, unconsumed food particles)
settle to the bottom of the tank and form a sludge layer. The sludge is
denser than water and fluid in nature, so it forms a flat layer along the
tank bottom. Underwater anaerobic bacteria consume organic materials in the
sludge, giving off gases in the process and then, as they die off, become
part of the sludge.

Effluent: Effluent is the clarified wastewater left over after the scum has
floated to the top and the sludge has settled to the bottom. It is the
clarified liquid between scum and sludge. It flows through the septic tank
outlet into the drain field.

Effective volume: The floating scum layer on top and the sludge layer on the
bottom take up a certain amount of the total volume in the tank. The
effective volume is the liquid volume in the clear space between the scum
and sludge layers. This is where the active solids separation occurs as the
wastewater sits in the tank.

Retention time: In order for adequate separation of solids to occur, the
wastewater needs to sit long enough in the quiescent conditions of the tank.
The time the water spends in the tank, on its way from inlet to outlet, is
known as the retention time. The retention time is a function of the
effective volume and the daily household wastewater flow rate:

Retention Time (days) = Effective Volume (gallons)/Flow Rate (gallons per day)
A common design rule is for a tank to provide a minimum retention time of
at least 24 hours, during which one-half to two-thirds of the tank volume is
taken up by sludge and scum storage. Note that this is a minimum retention
time, under conditions with a lot of accumulated solids in the tank. Under
ordinary conditions (i.e., with routine maintenance pumping) a tank should
be able to provide two to three days of retention time.
As sludge and scum accumulate and take up more volume in the tank, the
effective volume is gradually reduced, which results in a reduced retention
time. If this process continues unchecked-if the accumulated solids are not
cleaned out (pumped) often enough-wastewater will not spend enough time in
the tank for adequate separation of solids, and solids may flow out of the
tank with the effluent into the drain field. This can result in clogged pipes
and gravel in the drain field, one of the most common causes of septic system


In order to avoid frequent removal of accumulated solids, the septic tank is
(hopefully) designed with ample volume so that sludge and scum can be stored
in the tank for an extended period of time. A general design rule is that
one-half to two-thirds of the tank volume is reserved for sludge and scum
accumulation. A properly designed and used septic system should have the
capacity to store solids for about five years or more. However, the rate of
solids accumulation varies greatly from one household to another, and actual
storage time can only be determined by routine septic tank inspections.


While fresh solids are continually added to the scum and sludge layers,
anaerobic bacteria (bacteria that live without oxygen) consume the organic
material in the solids. The by-products of this decomposition are soluble
compounds, which are carried away in the liquid effluent, and various gases,
which are vented out of the tank via the inlet pipe that ties into the house
plumbing air vent system.
Anaerobic decomposition results in a slow reduction of the volume of
accumulated solids in the septic tank. This occurs primarily in the sludge
layer but also, to a lesser degree, in the scum layer. The volume of the
sludge layer is also reduced by compaction of the older, underlying
sludge. While a certain amount of volume reduction occurs over time, sludge
and scum layers gradually build up in the tank and eventually must be pumped


The inlet and outlet ports of the tank are generally equipped with devices
such as baffles, concrete tees, or in more recent years, sanitary tees
(T-shaped pipes with one short and one long leg).

The inlet device dissipates the energy of the incoming flow and deflects it
downwards. The vertical leg of the tee extends below the liquid surface well
into the clear space below the scum layer. This prevents disturbance of the
floating scum layer and reduces disruptive turbulence caused by incoming
flows. The inlet device also is supposed to prevent short-circuiting of
flows across the water surface directly to the outlet.
The upper leg of the inlet should extend well above the liquid surface in
order to prevent floating scum from backing up into, and possibly plugging,
the main inlet pipe. The open top of the inlet tee allows venting of gases
out of the tank through the inlet pipe and fresh air vents of the household

The outlet device is designed to retain the scum layer within the tank. A
sanitary tee can be used with the lower leg extending below the scum layer.
The elevation of the outlet port should be 2 to 3 inches below the elevation
of the inlet port. This prevents backwater and stranding of solids in the
main inlet pipe during momentary rises in the tank liquid level caused by
surges of incoming wastewater.

Typical inlet/outlet tees

Gas Deflection Baffle

Gases are produced by the natural digestion of sludge at the bottom of the
tank, and particles of sludge can be carried upward by these rising gases.
Some tanks have a gas deflection baffle, which prevents gas bubbles (to
which solid particles often adhere) from leaving the tank by deflecting them
away from the outlet and preventing them from entering the drain field.


In newer systems, there is often an effluent filter: one of the significant
improvements in septic tank design in decades. They range from 4 to 18
inches in diameter. As we have described, the most serious problem with
septic systems is the migration of solids, grease, or oil into the
drain field, and the filter is effective in preventing this.
A filter restricts and limits passage of suspended solids into the effluent.
Solids in a filtered system's effluent discharge are significantly less than
those produced in a non-screened system.


The septic tank also provides a buffering of flows between the house and the
drain field. Large surges from the household, such as toilet flushing or
washing machine drainage, are dampened by the septic tank so that the flows
leaving the tank and entering the drain field are at substantially lower flow
rates and extend over a longer period of time than the incoming surges.


In 1907, W. P. Dunbar conducted tests on the decomposition of vegetable and
animal matter in septic tanks. He stated, "The author has investigated the
subject by suspending in septic tanks a large number of solid organic
substances, such as cooked vegetables, cabbages, turnips, potatoes, peas,
beans, bread, various forms of cellulose, flesh in the form of dead bodies
of animals, skinned and unskinned, various kinds of fat, bones, cartilage,
etc., and has shown that many of these substances are almost completely
dissolved in from three to four weeks. They first presented a swollen
appearance, and increased in weight. The turnips had holes on the surface,
which gradually became deeper. The edges of the cabbage leaves looked as
though they had been bitten, and similar signs of decomposition were visible
in the case of other substances. Of the skinned animals, the skeleton alone
remained after a short time; with the unskinned animals the process lasted
rather longer. At this stage I will only point out that the experiments were
so arranged that no portion of the substances could be washed away; their
disappearance was therefore due to solution and gasification."

potential health risk to your family

Radon Information

Radon comes from the natural breakdown of uranium in soil, rock and water. The release of this radioactive gas enters the air you breathe, causing a potential health risk to you and your family.

Radon gas can be found in just about anywhere. It can get into any type of building — homes, offices, and schools — and build up to high levels. 

What you should know about Radon 

Radon is a cancer causing radioactive gas. You cannot see radon and you cannot smell it or taste it, but it may be a problem in your home. This is because when you breathe air-containing radon, you increase your risk of getting lung cancer. In fact, the Surgeon General has warned that radon is the second leading cause of lung cancer.

You should test for radon. Testing is the only way to find out about your home's radon level. The EPA and the Surgeon General recommend testing of all homes below the third floor for radon.

You can fix a radon problem. If you find that you have high radon levels, there are ways to fix a radon problem. Even very high levels can be reduced to acceptable levels.

If you are buying a home. EPA recommends that you obtain the radon level in the home you are considering buying. An EPA publication "The Home Buyer's and Seller's Guide" is available through most State Health Departments or Regional EPA offices listed in your local phone book. EPA also recommends that you use a certified or state licensed radon tester to perform the test. If elevated levels are found it is recommended that these levels be reduced. In most cases, a professional can accomplish this at reasonable cost or homeowner installed mitigation system that adheres to the EPA's approved methods for reduction of radon in a residential structure.

What are the Risk Factors?

The EPA, Surgeon General and The Center for Disease Control, have all agreed that continued exposure to Radon gas can cause lung cancer.

In fact, their position on the matter is that all homes should be tested for radon gas exposure, and all homes testing over 4 pCi/L should be fixed.

How Does Radon Enter the Home?

Typically the air pressure inside your home is lower than the pressure in the soil around your home's foundation.

Due to this difference, your house acts like a vacuum, drawing radon gas in through foundation cracks and other openings of your home.

Radon may also be present in well water and can be released into the air in your home when water is used for showering and other household uses.

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Mold Information

What is Mold? Molds are fungi. Molds grow throughout the natural and built environment. Tiny particles of mold are present in indoor and outdoor air. In nature, molds help break down dead materials and can be found growing on soil, foods, plant matter, and other items.

Molds produce microscopic cells called “spores” which are very tiny and spread easily through the air. Live spores act like seeds, forming new mold growths (colonies) when they find the right conditions.

What does mold need to grow? Mold only needs a few simple things to grow and multiply:
  • Moisture
  • Nutrients
  • Suitable place to grow
Of these, controlling excess moisture is the key to preventing and stopping indoor mold growth. Should I be concerned about mold in my home? Mold should not be permitted to grow and multiply indoors. When this happens, health problems can occur and building materials, goods and furnishings may be damaged. Health Effects Can mold make me and my family sick? Mold can affect the health of people who are exposed to it. People are mainly exposed to mold by breathing spores or other tiny fragments. People can also be exposed through skin contact with mold contaminants (for example, by touching moldy surfaces) and by swallowing it. The type and severity of health effects that mold may produce are usually difficult to predict. The risks can vary greatly from one location to another, over time, and from person to person. What symptoms might I see? The most common health problems caused by indoor mold are allergy symptoms. Although other and more serious problems can occur, people exposed to mold commonly report problems such as:
  • Nasal and sinus congestion
  • Cough
  • Wheeze/breathing difficulties
  • Sore throat
  • Skin and eye irritation
  • Upper respiratory infections (including sinus)
Are the risks greater for some people? There is wide variability in how different people are affected by indoor mold. However, the long term presence of indoor mold growth may eventually become unhealthy for anyone. The following types of people may be affected more severely and sooner than others:
  • Infants and children
  • Elderly people
  • Individuals with respiratory conditions or sensitivities such as allergies and asthma
  • Persons having weakened immune systems (for example, people with HIV infection, chemotherapy patients, organ transplant recipients)
Those with special health concerns should consult a medical professional if they feel their health is affected by indoor mold. Are some molds more hazardous than others? Some types of mold can produce chemical compounds (called mycotoxins) although they do not always do so. Molds that are able to produce toxins are common. In some circumstances, the toxins produced by indoor mold may cause health problems. However, all indoor mold growth is potentially harmful and should be removed promptly, no matter what types of mold is present or whether it can produce toxins. Home Investigation How do I tell if I have a mold problem? Investigate, don't test. The most practical way to find a mold problem is by using your eyes to look for mold growth and by using your nose to locate the source of a suspicious odor. If you see mold or if there is an earthy or musty smell, you should assume a mold problem exists. Other clues are signs of excess moisture or the worsening of allergy-like symptoms.
  • Look for visible mold growth (may appear cottony, velvety, granular, or leathery and have varied colors of white, gray, brown, black, yellow, green). Mold often appears as discoloration, staining, or fuzzy growth on the surface of building materials or furnishings. When mold is visible, testing is not recommended.
  • Search areas with noticeable mold odors.
  • Look for signs of excess moisture or water damage. Look for water leaks, standing water, water stains, condensation problems. For example, do you see any watermarks or discoloration on walls, ceilings, carpet, woodwork or other building materials?
  • Search behind and underneath materials (carpet and pad, wallpaper, vinyl flooring, sink cabinets), furniture, or stored items (especially things placed near outside walls or on cold floors). Sometimes destructive techniques may be needed to inspect and clean enclosed spaces where mold and moisture are hidden; for example, opening up a wall cavity.
Should I test for mold? We do not recommend testing for mold yourself. Instead, you should simply assume there is a problem whenever you see mold or smell mold odors. Testing should never take the place of visual inspection and it should never use up resources that are needed to correct moisture problems and remove all visible growth. Sometimes, mold growth is hidden and difficult to locate. In such cases, a combination of air (outdoor and indoor air samples) and bulk (material) samples may help determine the extent of contamination and where cleaning is needed. However, mold testing is rarely useful for trying to answer questions about health concerns. Mold Clean-up and Removal To clean up and remove indoor mold growth, follow steps 1-6 as they apply to your home.
    1. Identify and Fix the Moisture Problem - the most important step in solving a mold problem is to identify and correct the moisture sources that allowed the growth in the first place. Common indoor moisture sources include:
      • Flooding
      • Condensation (caused by indoor humidity that is too high or surfaces that are too cold)
      • Movement through basement walls and slab
      • Roof leaks
      • Plumbing leaks
      • Overflow from tubs, sinks, or toilets
      • Firewood stored indoors
      • Humidifier use
      • Inadequate venting of kitchen and bath humidity
      • Improper venting of combustion appliances
      • Failure to vent clothes dryer exhaust outdoors (including electric dryers)
      • Line drying laundry indoors
      • House plants - watering them can generate large amounts of moisture
To keep indoor surfaces as dry as possible, try to maintain the home's relative humidity between 20-40 percent in the winter and less than 60 percent the rest of the year. You can purchase devices to measure relative humidity at some home supply stores. Ventilation, air circulation near cold surfaces, dehumidification, and efforts to minimize the production of moisture in the home are all very important in controlling high humidity that frequently causes mold growth in our cold climate.
  1. Begin Drying All Wet Materials - as soon as possible, begin drying any materials that are wet. For severe moisture problems, use fans and dehumidifiers and move wet items away from walls and off floors. Check with equipment rental companies or restoration firms to see if you can rent fans and dehumidifiers.
  2. Remove and Dispose of Mold Contaminated Materials - items which have absorbed moisture (porous materials) and which have mold growing on them need to be removed, bagged and thrown out. Such materials may include sheet rock, insulation, plaster, carpet/carpet pad, ceiling tiles, wood products (other than solid wood), and paper products. Likewise, any such porous materials that have contacted sewage should also be bagged and thrown away. Non-porous materials with surface mold growth may be saved if they are cleaned well and kept dry (see step 4).
    • Take Steps to Protect Yourself - the amount of mold particles in air can increase greatly when mold is disturbed. Consider using protective equipment when handling or working around mold contaminated materials. The following equipment can help minimize exposure to mold:
      • Rubber gloves
      • Eye goggles
      • Outer clothing (long sleeves and long pants) that can be easily removed in the work area and laundered or discarded
      • Medium-efficiency or high-efficiency filter dust mask (these can be found at safety equipment suppliers, hardware stores, or some other large stores that sell home repair supplies) -- at a minimum, use an N-95 or equivalent dust mask
    • Take Steps to Protect Others - plan and perform all work to minimize the amount of dust generated. The following actions can help minimize the spread of mold spores:
      • Enclose all moldy materials in plastic (bags or sheets) before carrying through the home
      • Hang plastic sheeting to separate the work area from the rest of the home
      • Remove outer layer of work clothing in the work area and wash separately or bag
      • Damp clean the entire work area to pick up settled contaminants in dust
  3. Clean Surfaces - surface mold growing on non-porous materials such as hard plastic, concrete, glass, metal, and solid wood can usually be cleaned. Cleaning must remove and capture the mold contamination, because dead spores and mold particles still cause health problems if they are left in place.
    • Thoroughly scrub all contaminated surfaces using a stiff brush, hot water and a non-ammonia soap/detergent or commercial cleaner
    • Collect excess cleaning liquid with a wet/dry vacuum, mop or sponge
    • Rinse area with clean water and collect excess rinse water
  4. Disinfect Surfaces (if desired) - after cleaning has removed all visible mold and other soiling from contaminated surfaces, a disinfectant may be used to kill mold missed by the cleaning. In the case of sewage contamination, disinfection must be performed. Contact your home inspector for advice.
    • Mix 1/4 to 1/2 cup bleach per gallon of water and apply to surfaces where mold growth was visible before cleaning. The solution can be applied with a spray bottle, garden sprayer, it can be sponged on, or applied by other methods.
    • Collect any run-off of bleach solution with a wet/ dry vacuum, sponge or mop. However, do not rinse or wipe the bleach solution off the areas being treated -- allow it to dry on the surface.
    Always handle bleach with caution. Never mix bleach with ammonia -- toxic chlorine gas may result. Bleach can irritate the eyes, nose, throat, and skin. Provide fresh air (for example, open a window or door). Protect skin and eyes from contact with bleach. Test solution on a small area before treatment, since bleach is very corrosive and may damage some materials.
  5. Remain on Mold Alert - Continue looking for signs of moisture problems or return of mold growth. Be particularly alert to moisture in areas of past growth. If mold returns, repeat cleaning steps and consider using a stronger solution to disinfect the area again. Regrowth may signal that the material should be removed or that moisture is not yet controlled.
When can we rebuild? Rebuilding and refurnishing must wait until all affected materials have dried completely. Be patient it takes time to dry out wet building materials.