Mold Testing Services
Mold Testing -- Sioux Falls, South Dakota
Cleaning Up Mold
Cleaning Up Mold – General Concerns
Cleaning Up Mold – Basic Steps
Cleaning Up Mold – What Can Be Cleaned?
Cleaning Up Mold – Minor Exposed Visible Mold (<1 ft2)
Cleaning Up Mold -  Moderate Exposed Visible mold (<10 ft2)
Cleaning Up Mold – Opening Up Moldy Walls (Hidden Mold)
Cleaning Up Mold – Lots of Mold (Exposed or Hidden)
Cleaning Up Mold – Why Use A Cleaning Firm
Cleaning Up Mold – Why Do Clearance Testing
Cleaning Up Mold – Guidance for Cleaning Firms
Cleaning Up Mold - References


The main concern from is INHALATION from AIRBORNE mold. Whenever a mold clean-up is performed, the disturbances associated with clean-up often cause extremely high levels of airborne mold. This can pose immediate health concerns and may cause airborne mold to spread to other rooms and floors.   Visible mold can occur on walls or behind walls and yet the room may show normal airborne mold levels. However, during drying or mold removal, especially when opening up walls, high levels of mold may become airborne. The fiberglass insulation behind opened walls also is often very moldy and may contribute to high airborne levels when disturbed. Wet mold may be less likely to become airborne than would mold exposed to drying activities. Even very small amounts of visible mold can sometimes cause surprisingly high airborne mold levels.

Improper mold clean-ups can turn a minor mold concern into a major problem. Water clean-up activities or remodeling (often bathrooms, kitchens, basements) may discover large amounts of mold behind walls or cabinets, etc.  

A contractor performing a poor clean-up may create an expensive clean-up problem (entire house may need to be cleaned) and create health concerns that can cause pose significant liability concerns. In the experience of MTS, general contractors and homeowners often fail to appreciate the effort and attention to detail required to do an adequate mold clean-up. General contractors and homeowners often fail clearance testing after self clean-up.

The goal of mold clean-ups should be to minimize mold disturbance and minimize exposure to airborne mold.

In some cases, even when visible mold is not obvious, very high airborne mold levels may exist before a clean-up. BEFORE starting a clean-up, it can be useful to take some airborne mold tests to determine if precautions are needed and which rooms or floors may need to be cleaned. For example, in a house with a moldy basement, will it be necessary to also clean the main floor?

The cause of a mold problem is always related to moisture problems. Ideally, BEFORE starting a mold clean-up, the cause of the mold (the water problem) should be identified and corrected. For example, a mold problem caused by a leaky roof will do little good unless the roof leak is first fixed.

Consider special circumstances. For example, a hospital, nursing home or day care center may require extra precautions and effort. For persons with asthma, it may be necessary for them to be away from the building until the work is completed.


Step 1.      Plan ahead. Minimize Disturbance.
Step 2.     Correct the Cause (Water Problem). Control Humidity.
Step 3.     Wear respiratory protection
Step 4.     Provide containment (isolate the work area).
Step 6.     Isolate Ventilation Systems
Step 5.     Minimize and contain airborne mold in the work area
Step 6.    Remove Carpets & Contents
Step 6.    Minimize & contain airborne mold and dust in the work area.
Step 7.    Removing Carpets & Contents
Step 8.    Removing Moldy Materials.  
Step 9.   Clean All Surfaces in Affected Rooms.  
Step 10. Perform Post Clean Up Verification.
Step 11. Post clean-up considerations.

Step 1. Plan Ahead. For any mold clean-up, the first step is to PLAN AHEAD. For example, if you are planning to remodel your bathroom or to remove wet walls in a basement, ASSUME that a mold concern may exist. Even when mold is not present, containment efforts, etc. can help to minimize dust, odors and volatile chemicals spreading to other rooms. If extensive visible mold is discovered during a project, especially in an occupied building, STOP WORK immediately.  Develop a plan to handle the situation. Avoid turning a minor problem into a big problem. For example, if remodeling discovers lots of visible mold when opening up a wall, stop opening up the wall and temporarily cover it up and then make plans as to what to do.

Workers with asthma or severe respiratory problems should NOT participate in clean-ups. Children and the elderly should NOT participate in clean-up work (inside containment areas). Preferably, workers with some training should be used. MTS is aware many contractors and homeowners prefer to do their own clean-ups and often fail to appreciate the effort required to do a good clean-up (and minimize airborne mold). Anyone expressing a lack of concern and unwillingness to follow instruction or to wear a respirator should not be allowed to participate.

Step 2. Correct the Cause (Water Problem). If feasible.  Reduce the humidity.  The cause of a mold problem is always related to water damage. Ideally, the cause of the water problem should be identified and fixed BEFORE performing a mold clean-up. This is not always practical. Examples include fixing a pipe leak or roof leak or improving drainage around the outside of a house. Where a basement may need drain tile installed inside the basement, this may require cutting into floors and walls and stirring up lots of dust and mold. In some cases, containment, respirators, etc may be needed before fixing the cause of the problem.

For water clean-ups, it is very important that water removal and drying be performed as quickly as possible (within 48 hours). This often requires the use of blowers which may blow dust and mold around. Drying efforts may require removing portions of walls. This may stir up dust and mold.  Where a water clean-up has the potential to stir up dust and mold, appropriate precautions may be needed. The necessity for quickly drying must be balanced against what these efforts may do to cause mold concerns. When in doubt, it is often more important to provide quick drying than to wait for several days while making containment arrangements (or to find the cheapest firm). If walls (without pre-existing mold) can be dried within 48 hours, mold growth will often not occur. However, if drying is delayed for several days, considerable mold growth may occur.

Ideally, rooms should be relatively dry during mold clean-ups. However, reducing humidity and drying efforts may allow mold on drying surfaces to become airborne. Mold tends to be less airborne from wet surfaces than from dry surfaces. The use of strong blowers, while helping to dry surfaces may stir up high levels of mold. When mold is an obvious concern, the use of dehumidifiers alone (rather than with blowers)may be preferable.

The relative humidity should preferably be kept below 50% in rooms where mold clean-up is needed. Relative humidity less than 40% is often recommended for drying efforts. Failure to control the relative humidity may allow continued mold growth to occur during and after a mold clean-up. Commercial grade dehumidifiers are often needed. As an aside, the limited filters used on dehumidifiers can often remove a surprising amount of airborne mold during water clean-up and drying.

Step 3. Wear respiratory protection and protective clothing.  The main concern from mold is INHALATION. Some form of respiratory protection should ALWAYS be worn. The two strap disposable dust mask (called N-95 respirators) are often sufficient.  Disposable tyvex coveralls, gloves and goggles are sometimes useful, especially when working with fiberglass insulation. However, the most important concern is having respiratory protection. Ideally, the respirators should be fit-tested to make sure they work (a fit test uses an irritating or smelly airborne chemical to make sure the respirator does not leak).   

Step 4. Provide containment (isolate the work area).  The area of concern should be contained (isolated) from other rooms or floors BEFORE starting any mold removal efforts. Plastic sheeting is often taped over doors or stairwells. In some cases, a portion of a room can be contained with temporary barriers (such as in an occupied office).

With adequate containment and precautions, it is often NOT necessary for office workers or homeowners to leave a building during clean-up. For example, containment can be provided for a moldy basement while allowing the homeowners to still live on the main floor.

Various types of access “doors” (overlapping plastic flaps, zipper seals, etc over doorways) can be used to provide access to contained areas.  Unauthorized persons should NOT be allowed into containment areas. Clearly marked signage  “KEEP OUT – BIOLOGIC HAZARD”  may be helpful.  When using tape to attach plastic to walls, the direct application of duct tape should be avoided (when possible) as this often removes paint or damages wallpaper etc. Painter’s removal tape can be used on surfaces with duct tape then applied over it.

Where feasible, negative air pressure should be used, at least in the initial tear-out and clean-up efforts. Negative air pressure means the containment area has less air pressure than adjacent rooms. In other words, airborne contaminants (mold, dust, etc.) will not be able to flow into other rooms. Negative air can often be applied by using fans or HEPA air scrubbers through outside windows, doors or available vents. In some cases, no outside discharge area is available. In these cases, a secondary containment can be constructed with a HEPA air scrubber discharging from the primary (moldy) room into the secondary containment. Rooms under negative air pressure typically show plastic barriers sucked inward toward the containment room.  Caution should be used when blowing unfiltered air to the outside. This should be away from where persons may breathe in this possibly moldy air.

Step 5. Isolate Ventilation System.  Most buildings have forced air ventilation using supply air diffusers and return air vents. In problem rooms, it is preferable to close off both the supply air and , especially, the return air vents.  It is true that supply air vents when in use are under positive air pressure and will not tend to allow mold, etc into them. However, most ventilation systems operate intermittently turning on and off during the day depending on heating and cooling needed. The positive air pressure provided by supply air vents may also cause positive air pressure in a room, driving airborne mold into other rooms (rather than providing the preferred negative air).  In some cases, the ventilation system can be turned off but this is not always practical in cold or hot weather.

 Step 6. Minimize & contain airborne mold and dust in the work area. An adequate mold clean-up should CONTAIN and MINIMIZE airborne mold in the work area. Containment, preferably with negative air, should minimize mold and dust escaping the work area. Work should be planned to avoid many people continually coming in and out of the containment. It is preferable to use commercial grade HEPA air scrubber units.  HEPA air scrubbers are large, box shaped filter units with strong fans and high efficiency particulate arrestance (HEPA) filters and pre-filters (to collect larger fragments). They draw in unfiltered air and release filtered air.  These units are used by cleaning firms. They can sometimes be rented. They are fairly expensive to buy (>$1000s of dollars) and the HEPA replacement filters are expensive. However, they can often be rented from cleaning firms for about $75/day.

When HEPA air scrubbers are not available, much less effective room HEPA filter units or even pleated filters tied to box fans may provide some benefit. Most clean-ups stir up lots of dust and pre-filters are needed to avoid clogging up the expensive HEPA filters.

Step 7. Removing Carpets & Contents. It is important not to drag moldy belongings into rooms that are not moldy. Once containment is arranged and respirators are worn, the contents can be removed or otherwise isolated (sometimes covered over with plastic sheeting). It is often necessary to remove the contents of a room to provide clean-up. During removal, non-porous items (wood, metal, plastic, etc) can be damp wiped of obvious visible mold and temporarily stored elsewhere (in another room, the garage, etc).  Porous items (soft furniture, etc) may need more consideration.  See section on What Can Be Cleaned?.

In moldy basements, it is often preferable to remove carpeting (and underling pad) during a mold clean-up. Deep carpeting typically traps mold and is very difficult to completely remove mold spores from. Basement clean-ups where carpeting was cleaned and left in place often fail subsequent clearance tests. In some cases, the carpeting can be covered with plastic during a clean-up. For commercial grade carpeting (short fibers), cleaning is sometimes effective and removal may not be needed.

To remove carpeting, the carpet can be cut into strips, rolled up and placed in plastic bags. Or, the carpet can be rolled up and wrapped in plastic sheeting. It is preferable not to drag large moldy carpets through a building to remove them.

On main floors above moldy basements, removal of carpeting is sometimes not necessary. Steam cleaning and/or HEPA vacuuming may be sufficient to minimize mold in carpeting on upper floors. However, in some cases, it may be necessary to remove the carpeting to achieve normal airborne mold levels.

Step 8. Removing Moldy Materials.  The removal of any mold materials should be done in a way to minimize disturbance. Moldy surfaces can be first covered before removal or otherwise immediately placed into plastic bags or wrapped in plastic.  Masking tape, duct tape, wet newspaper, plastic sheeting, etc can be used to cover moldy materials before removal. Moldy surfaces can be lightly sprayed with a fine water mist to minimize airborne mold.
Removal of moldy materials should be done in a manner to minimize disturbance. Using hammers to smash out drywall,etc. should be avoided if the materials can be pried out carefully. Large panels can be cut into smaller pieces for bagging.

Where visible mold is present on drywall, it is preferable to remove drywall at least 1-2 ft above the visible mold. Drywall tends to show dampness above visible mold and small amounts of mold not readily visible may extend 1-2 ft above the obvious visible mold (especially on the back side of walls). For replacing drywall, it is often easier to simply remove the entire lower 4 ft high panels and replace them. Insulation behind moldy walls should usually be removed.

Rooms with outside doors or windows are useful to remove moldy materials to the outside rather than dragging them through the building.

Materials to be removed should include moldy or water damaged materials such as drywall, rotted wood supports or sheathing, and fiber glass and other forms of loose insulation. Solid wood can often be sanded or brushed clean.

Moldy materials can usually be accepted at a permitted landfill. Moldy materials should be in plastic bags and covered containers in vehicles.

Step 9.  Clean All Surfaces in Affected Rooms.  After removing moldy materials, all room surfaces should be cleaned. This should include walls, ceilings and floors. It may help to work from top to bottom.  It is very important to clean ALL surfaces. Mold spores may stick to walls, ceiling, carpeting,etc. Surfaces can be HEPA vacuumed and/or damp wiped. Commercial grade HEPA vacuum cleaners are preferable. These can be rented. When damp wiping, disposable sponges or rags should be used. Micro-fiber materials may also be used and disposed of.  In basements, ceiling joists and the ceiling (main floor subfloor) should be included in the clean-up. This may require considerable effort, reaching into corners and around piping, HVAC ductwork etc.

Use of water should be minimized during mold clean-ups. Light misting of surfaces to be removed can help to hold down airborne mold levels. However, large amounts of water typically tend to promote mold growth and wet materials are more difficult to remove mold from. High pressure water hoses are NOT recommended for mold clean-ups. The high pressure not only saturates wood and other surfaces but can cause very high levels of airborne mold. Nevertheless, in a few situations, such as where rooms are made entirely of concrete, this might be an option.

Disinfectants are often used when damp wiping. Caution should be using when using disinfectants, especially bleach. Exposure to strong disinfectants may pose more of a health concern than exposure to mold. Many disinfectants are strong irritants to the respiration system, eyes and nose.  Studies have shown workers in the cleaning industry who frequently use disinfectants often develop respiratory problems and asthma. Standard respirators for dust offer NO protection to the vapors from cleaning chemicals.  Disinfectants should be used in well ventilated areas. In many cases, containment areas are not well ventilated.  There is considerable misunderstanding about using disinfectants. There is little point in trying to “sterilize” a room with strong chemicals. The key to mold growth is moisture. If the surfaces of a room become damp, it does not matter whether the surfaces had been disinfected. Mold will grow again. In fact, disinfectants are often NOT needed for an adequate clean-up. Rather, damp sponges or rags, moistened with soapy water, is often adequate.

Ozone treatments are sometimes used for mold clean-ups. This is often much cheaper than a standard mold clean-up. The rooms must not be occupied during the treatments. Plants and some objects may be damaged by the treatment. Ozone is useful at reducing odors (often used for smoke damage) but is controversial for mold clean-ups. It is true that strong doses of ozone will kill lots of living mold. However, mold is an allergen and toxin whether living or dead. Ozone treatment is not recommended by the US EPA for mold clean-ups. Ozone treatment can be part of a mold clean-up. But, the clean-up should typically include physical removal of all mold, use of HEPA air scrubbers, etc. MTS has sometimes found elevated airborne mold levels in rooms after ozone treatments.

Step 9.  Completing the clean-up. When a mold clean-up is completed, containment and HEPA air scrubbers should be kept in use for as long as possible. It is often preferable to leave both containment and HEPA air scrubbers in use until post clean-up testing is performed.  Negative air can often be turned off after the primary clean-up.

Exposed surfaces, especially wood, are sometimes covered with antimicrobial encapsulants (typically a white colored paint). This may help to minimize future mold growth but in the experience of MTS, mold growth may reappear on such treated surfaces after a few months, especially if they are persistently wet or damp. Perhaps the most useful role of these encapsulants is to provide a clear visual indication of what areas were cleaned. Painted (liquid paint) treatments are typically more effective than use of sprayed paint (much thinner coating with sprayed paint). Painted surfaces also provide a professional “finish” to a clean-up.

Optional. In some cases, mold stirred up during the clean-up may settle out onto the floor or other surfaces. Some cleaning firms or consultants include an additional “air-washing” after the mold clean-up. The air in the room is stirred up with strong fans (leaf blowers, compressed air, etc) while HEPA air scrubbers are in use.  Mold levels are extremely sensitive to dust disturbance and such efforts may inadvertently cause much higher mold levels than before.

In many cases, clean-up of the HVAC system and ductwork is performed after (or during) a mold clean-up. There is considerable controversy over the effectiveness of cleaning ductwork to reducing health symptoms. However, in a moldy building, it does not hurt and may help. Large amounts of mold and dust may be present in the ductwork. The use of biocides for clean-up in HVAC systems is not recommended. The health effects of exposure to such chemicals is not well understood and may be harmful to some persons.

Step  10. Perform Post Clean Up Verification. This is sometimes called “clearance” testing. Ideally, post clean-up testing should be performed at the end of the clean-up by an independent third party. A strong flashlight is typically used to make sure no obvious visible mold remains. Airborne mold testing is very important as extremely high airborne mold levels may occur after a clean-up. This will not be obvious to the naked eye. Airborne mold testing helps to verify that an adequate mold clean-up was performed and that a mold concern no longer exists. Cleaning firms, home buyers, bankers, etc. often insist on post clean-up airborne mold testing to document a concern no longer exists.

When doing post clean-up testing, it is often preferable to keep up the containment and use of HEPA air scrubbers until the testing is completed.  However, negative air machines should usually be turned on at least a day or more before testing. Negative air sometimes causes airborne mold to be drawn from other rooms, cracks in walls, opened insulation, etc. and may complicate getting adequate results. There is some argument as to whether post clean-up testing should be done with HEPA air scrubbers on or off.  MTS has experimented with both and found little difference between the two.

Post clean-up testing is typically done after removal of walls and before the walls are replaced. This allows for visual inspection before the walls are covered over.

Post clean-up testing should be done as quickly as possible after the mold clean-up. Waiting for several days while contractors go back to work on the rooms, etc may stir up fresh sources of mold and dust. In some cases, especially older buildings with opened up plaster lath walls, during remodeling,etc., it may be difficult to achieve normal airborne mold levels after a clean-up as long as there are opened walls. In some instances, it may be preferable to complete the clean-up and remodeling, enclosing the walls, before final post clean-up mold testing.

Step 11.  Post clean-up considerations. After the clean-up, putting the rooms back together should take into consideration avoiding future mold problems. Replaced sill plates should be treated wood or encapsulated (polyurethane varnish is very effective, often better than antimicrobial paints – paint brushed, not sprayed).

In basements, foam insulation (sprayed or solid) is preferable to fiberglass insulation. In rooms or areas sensitive to moisture and mold, the use of mold resistant materials, such as fiberglass backed drywall (Dens Armor Plus,etc) or bathroom grade blueboard, etc is preferable to standard paper faced interior drywall.

Along the bottom of the drywall in basements, a ½ inch gap (capillary break) is recommended between the bottom of the drywall and concrete floor. This helps minimize future moisture wicking from the concrete and water leaks being able to wick into the drywall.

The use of vinyl wallpaper or wood veneer wainscotting is not recommended for basement exterior walls over standard drywall. These act as vapor barriers trapping moisture against the drywall and allowing mold growth.

Steps to control relative humidity should be considered, especially in basements. It may be necessary to use dehumidifiers or install an exhaust fan to the outside (often with an automatic RH sensor). Relative humidity should be kept below 50% in the warmer months.


There is often great concern as to what family belongings can or cannot be cleaned of mold. There are two major categories: (1) Non-porous materials and: (2) Porous materials. It should be emphasized there is an important difference between active mold growth within materials as opposed to light growth on surfaces or dead or dormant mold spores present in settled dust. There is often no easy black and white choice in these matters. Obviously water damaged materials should be discarded. However, many objects can be safely cleaned.  Where young children, the elderly or asthmatics are involved, it is sometimes better to err on the side of caution.

Non-Porous Materials. This includes metal, plastic, solid wood, glass, ceramics and any other objects with solid surfaces. These can be usually be readily cleaned by damp wiping. Use of strong disinfectants is typically NOT needed and may damage some objects (bleach). This category includes electronic equipment, televisions, hard furniture, bookcases, etc.

For solid wood, light wiping is often adequate. Rotted wood should be removed. In some cases, light sanding may be needed. Some molds cause light staining on the surfaces of wood (or on the varnish). This is not always possible to remove without damaging the “finish” of the wood. Certain wood products made of ground-up materials (particleboard) or chips (oriented strand board) are more prone to mold growth than solid wood. In some cases, these can be wiped or sanded. However, when water damaged or rotted, they should be removed.

Porous Materials.  This includes any material able to readily soak up water and provide an organic food source for mold. This includes clothing, soft furniture, rugs, mattresses, paper products, etc.  In many cases, as long as mold is not actively growing on and within the material, they can often be cleaned and saved. Clothing can usually be washed. Small or thin carpets can sometimes be HEPA vacuumed or beaten, etc or washed.

Wall to wall carpeting in basements, especially if water damaged, should usually be removed. In some cases, wall to wall carpeting can be cleaned and saved but this can be very difficult. Basements where carpets were cleaned during a mold clean-up often fail post clean-up tests until the carpeting is removed. Deep carpets act like giant filters. However, thin commercial grade carpeting can often be cleaned.

Mattresses and soft furniture if water damaged or strongly musty are often preferable to discard. However, such objects can often be HEPA vacuumed wiped and/or damp wiped.

Perhaps the biggest concern is over books, family photos and important paper documents and pictures.  These, unless obviously damaged, can quite often be saved by damp wiping. For books, often only the surface (cover and edges) need to be damp wiped rather than every single page.

Where there is concern over saving valuable objects or furniture (after removing any visible mold), mold testing can be performed after clean-up. Objects can be placed in plastic bags or covered with plastic sheeting. Disturbed conditions can be created (shaking, beating,etc) and the air space of the enclosed object then tested for airborne mold levels.


Visible mold or rot is sometimes found on the exterior siding of houses and offices. This often occurs on the north side of buildings. This usually poses no concern to airborne mold levels inside the house. No special precautions are usually needed, unless the repair work penetrates the walls inside the rooms.


This category emphasizes minor amounts of visible mold that can be found without opening up walls,etc.  Small amounts of visible mold occur in many homes and offices, especially in corners, basements, behind water heaters, sinks and washers and under sinks in kitchen and bathroom cabinets. Small amounts (often called mildew) can often be found in bathrooms on the bathtub or shower unit.  Small amounts are often found in closets and behind furniture along exterior walls. Small amounts are often found behind baseboards along exterior walls, especially in basements.

An especially common place to find minor visible mold is on window sills. Windows are almost always colder than the walls and act like condensing plates, allowing moisture in a room to condense against the glass and run down along the lower window sill. This is often sufficient for minor mold growth to feed on the dust, paint, drywall or wood on the window sill. This can usually be simply wiped off.

The term “small amount” is subjective but may be considered to include visible mold adding up to less than one square foot.  Many very small spots (1-2 inches wide) may not be as much of as larger spots. The location of the visible mold is also important. Visible mold in an old farmhouse basement is likely to be of much less concern than visible mold in a kitchen or hospital operating room.  Although it is preferable not to find “any” visible mold in an occupied building, the truth of the matter is that small amounts of visible mold often occur and yet often do not pose health concerns.

For minor mold spots, no special precautions are often warranted. The mold spots can often be simply wiped off with a rag and soapy water (or scrub brush) and disposed of.  Masking tape or duct tape can be applied directly to mold spots to remove it.


There is a grey area between minor mold spotting and extensive visible mold.  Various groups, including the New York City Dept of Health (NYCHD, 2008) and US EPA have mentioned 10 ft2 of visible mold as a “moderate” amount of mold. This is equivalent to an area about 3.3 ft x 3.3 ft (a square meter). This can be one large spot or several spots adding up this area.  This is still a fairly small amount of visible mold but it should be noted a single square inch of visible mold can contain millions of mold spores.  Where more than just a few very small mold spots are present, it may be appropriate to take precautions. This depends on the situation. Visible mold found during construction may not require the same efforts as in an occupied office. When visible mold is <10 ft2, the NYCHD suggests precautions including trained persons, respirators and use of HEPA air scrubbers. Containment may not be needed but the room should not be occupied by others during the clean-up. If walls are to be opened and removed as part of the clean-up, then containment should also be considered.


Where lots of visible mold occurs in many small or larger spots, a mold concern may exist. Lots of visible mold suggests dampness and may be associated with elevated airborne mold levels and even more mold hidden behind walls. Cleaning up such mold typically stirs up very high airborne mold levels and often poses a health risk. In these cases, precautions should include containment, respirators, HEPA air scrubbers and other measures, preferably with trained persons. See various guidelines.

When opening up walls to remove exposed visible mold, much more mold is quite often on the back side of the wall and in the insulation. Any time, walls are torn open (water damage, mold clean-up, remodeling, etc), it is often a good idea to assume lots of mold and dust may be stirred and to use mold related precautions such as containment, etc.


Here we are referring to cleaning firms experienced in mold remediation. Building owners and contractors often fail to appreciate the effort, training, equipment and attention to detail needed for a successful mold clean-up.  The “healthy worker” effect may come into play here. Building contractors, by the nature of their occupation, are often less sensitive to mold and allergies than others. They may not notice any symptoms that might affect someone else. A poor clean-up has the potential to stir up large amounts of airborne mold. This may create serious health concerns to the occupants. This may also spread mold from one small area throughout a building.

Cleaning firms have trained personnel and the proper equipment to provide containment, air scrubbers, etc.  In many cases, insurance may cover some of the clean-up and testing costs. This especially applies to water damage from a “sudden” release (flood, pipe break,etc). Insurance often does not cover mold associated with general dampness. Cleaning firms help to reduce the liability of the building owner or landlord.  The better cleaning firms insist on third party post clean-up mold testing to document they did a good job. If they fail this testing, they often will perform further clean-up (and pay for the testing) until they have passed.

The use of cleaning firms is preferable to many persons without the training to do. However, cleaning firms can be expensive. One must consider the use of trained personnel and equipment involved in the work.  In some situations, cleaning firms are willing to work with the building owner and provide advice or rental equipment. The homeowner may save money by cleaning off personal objects himself but still hire a cleaning firm to do a basement.