-H. L. Whitinsville, MA

What is mold remediation? How do you chose a mold remediation company? How do you know if they are qualified? Will they follow standard mold remediation procedures? Do they confidently stand by their work?

Mold remediation is a term used to describe the safe and effective method for removing mold contamination from an indoor environment. Generally, the mold remediation process includes the following steps: setting up appropriate containment barriers separating the moldy areas from otherwise unaffected areas, using negative air machines and/or HEPA filtered air scrubbers to exhaust/capture airborne particulates, removal of moldy materials (personal belongings, Sheetrock, insulation, wood, carpeting, etc.), and finally, cleaning remaining materials/belongings using special techniques. Sometimes abrasive actions are needed such as sanding or dry-ice blasting to remove mold from wood materials. EPA registered chemicals and sealants should be used and only in accordance with their documented application methods.

Choosing a qualified remediation company can be challenging. First, ask for qualifications, certifications, experience in the business, references, and if they strictly follow the ANSI/IICRC document S520 Standard and Reference Guide for Professional Mold Remediation. In the past few years, many new companies have sprouted up so it can be difficult to know which to hire; cost can vary greatly depending on the procedures used.  Standard procedures and guidelines for mold remediation were published in the ANSI/IICRC Document S520; this publication describes in detail the standards for and actions necessary to safely and effectively remove mold contamination. We have experience with companies that do not follow standard procedures or that cut corners to decrease client cost and the result is failed remediation. Mold remediation is expensive but if done correctly the first time, the money was spent wisely. There are gimmicks and trendy methods (ozonation, fogging, one step spraying with a killing agent, covering the mold with a white paint) to ‘get rid of mold’–these do not work.  Old fashioned, labor intensive elbow grease (with some chemicals and equipment) is a must.

GML recommends getting several quotes from mold remediation companies. Their written estimates will detail procedures to be used and the cost of the project. Compare the steps used between companies. There is a good reason why one company would give a quote that is significantly lower than another. If one of the major steps is left out, the cost will be less, but so will the quality of the work. In the end, the mold must be gone, as confirmed by an independent mold inspection company. Sometimes the remaining black discoloration on the wood is called ’staining’, but not mold, by the remediation company , but this is rarely true. Remediation must remove all signs of mold, black staining included.  

The most common health concern with mold is allergies. Most people are familiar with the runny noses, sneezing, watery  eyes, etc. associated with mold, pollen, and dust mite allergies. But have you heard of mycotoxins? These are chemicals produced by some molds under the right conditions.  Mycotoxins are generally associated with grain and nut crops. Wet hay bales are also a good source of toxins produced by mold. But did you know that mycotoxins can be found in grape juice, on apples and celery, and on other fruits and vegetables?

Molds on food come in a rainbow of colors from white to black and most colors in between. Sometimes, moldy foods must be thrown away. These include soft, fleshy fruits such as peaches, tomatoes, and cucumbers, sliced lunch meats, sour cream, and others that the mold cannot be cut away from. Molds have long, web-like structures that penetrate below the surface of softer foods. Patches of mold can be successfully cut away or removed from harder foods, for example apples, uncut hard salami, and hard cheeses.

Speaking of cheese, did you know that molds are intstrumental in manufacturing some cheeses? A mold called Penicillium roqueforti is used to make roquefort and gorganzola cheese. That white layer surrounding a wedge of brie cheese is also mold. These molds are safe to eat as long as you don’t have an existing sensitivity to mold.

So how do you prevent mold from growing on food in the refrigerator? Short turn around time. Mold spores are everywhere and all they need is a food source and sufficient moisture to grow so even though the refrigerator is cold, molds can begin devouring the prize tomatoes grown in your garden relatively quickly. The shorter amount of time foods spend in the refrigerator, the better chances they have of not becoming moldy. Several steps can help. Make sure the fridge is clean; spilled foods and liquids that remain on the bottom shelf are mold breeding grounds. Discarding food with visible mold can minimize the spread of mold to other foods. Clean moldy refrigerator gaskets. Cover foods. Transfer foods out of their original containers into storage containers with covers. Cut out visible mold that develops on hard cheeses that will remain in the fridge. Overall, eating foods in a time frame that doesn’t allow mold to take over is your best defense. 

And finally, eating a small amount of mold on food before you realize it is moldy is generally not enough to cause serious harm. We eat mold every day without knowing it so don’t panic if you see a fuzzy green spot on the peach you just began eating.  Throw it out and take another one, but be sure to inspect it before taking the first juicy bite!

Deborah Gordon, Gordon Mycology Laboratory, Inc. 2009

The end of winter is here.  We are excited about longer days, blooming flowers, and shout a long awaited hello to the warm sunshine. 

Unfortunately, this is the time of year snow mold rears its ugly head in our dormant lawns.  The UMass Extension and Rhode Island Cooperative Extension explain the symptoms of, and how to conquer, this menace so we can get our lawns ready for wigglin’ toes and puppy dog noses.

You’ll see the first insidious sign as small circular patches on the lawn in sizes of 3 – 12 inches in diameter.  Sometimes, if the mold takes hold, patches blend together to cover large sections of the lawn.  These molds are active in the colder, wetter times of the year, surviving and even thriving beneath the snow.  Visually, “…web-like mycelium of pink snow mold (Microdochium nivale) may initially look white and mature to a faint pink to salmon color.  Gray snow mold (Typhula spp.) is white to gray in color.” 

As temperatures rise, the snow melts, and the sun beats down on awakening lawns, New Englanders rejoice.  However, with spring weather patterns, snow molds become increasingly unhappy.  Most of the time, the normal emergence of warmer, sunnier weather is enough to kill snow molds.  Yard clean up, among other steps, is your best bet for snow mold deterrence and lush lawns. 

What to do next if you have snow mold?  Determine the type of mold, either pink or gray, that has infected your lawn.  The gray mold doesn’t do extensive damage, and typically the grass recovers quickly.   Pink snow mold gets to the heart of the grass crowns and roots causing, sometimes, irreparable damage.  Often times, both types of snow molds can be found in our lawns.  An essential step for snow mold prevention is taking away its comfortable home — rake up dead leaves and clean debris from lawns.  A good choice of seed for replanting in areas that need to be cleaned out is Kentucky bluegrass, which is less susceptible to snow mold infection.  

Visit the following site for more details, photos, and prevention/eradication tips.

http://www.uri.edu/ce/factsheets/sheets/snowmolds.html

Happy Spring to you and your families. 

D. A. Boss, Gordon Mycology Laboratory, Inc. 2009

Case Study 09036: Successful Attic Mold Remediation

Facts/History/Observations:

An initial inspection by GML revealed that the mold Cladosporium was actively growing on plywood roof sheathing and on both gable ends in the attic.  A professional mold remediation company was hired to clean all surfaces in attic under environmental controls and using standard mold remediation procedures.  After the work was completed, we re-inspected the attic to determine if remediation was successful. 

Attic insulation was removed, leaving the topside of the second floor ceiling Sheetrock exposed. Among several other important steps, the plywood sheathing was dry-ice blasted (similar to sand blasting except dry ice pellets were used as the abrasive agent).  Visual evidence of mold was no longer present.

Successfully Remediated Roof Sheathing

Inspection Strategy:

• Visual inspection of attic
• Surface swab sampling from several representative areas of the previously moldy plywood sheathing

Lab Results:

• Lab results describe a negligible amount of mold spores
• The current level of mold on wood materials in the attic is normal
• Remediation was completely successful

Recommendations:

• Maintain a dry and well ventilated attic
• Re-install insulation

Facts/History:

The owners of a two story Colonial were away on vacation for one month. When they returned home, they found the house flooded, on all levels. A failed component of the heating system caused the heat to turn off during a cold spell. Water and heat pipes froze and burst throughout the house causing extensive water damage; walls, ceilings, and floors were saturated. Water poured through central air conditioning system ductwork and recessed light fixtures. A professional flood response company was brought in immediately to remove wet belongings and building materials and to dry those that remained; drying holes were cut in the base of walls, Sheetrock and insulation was removed in certain areas, wall-to-wall carpeting and the finished basement floor was removed, and the interior of the house dried. Most personal belongings in the home were affected and had been removed (thrown away or cleaned and stored off-site) prior to our inspection; the house was completely empty.

Observations:

The finished basement sustained the most water damage. The basement ceiling was completely torn out, as well as some walls. The laminate flooring in the basement was also removed. Exposed fiberglass insulation remained in the furnace room ceiling. All baseboards were removed and drying holes made in the base of most walls in the house. The kitchen and finished garage were mostly ‘gutted’ because they took on so much water. No building materials were wet on the inspection day. Widespread water staining was noted on walls and ceilings. Hardwood flooring remained on the first floor and was badly warped and cupped; boards were separating and dark discoloration was noted in the seams. Bathroom tile floors remained on the second floor but linoleum floors on the first floor had been removed. Many sections of plywood sub-flooring were exposed and some water staining, but no visible mold, was present. There was no mold odor on the first or second floors and minimal visible mold was discovered on the base of two Sheetrock walls in the basement; a slight mold odor was detected in the basement.

Gutted kitchen

Damaged hardwood floor and drying holes

Sampling Strategy:

GML was brought in to do a mold inspection to determine if the flooding caused mold growth on building materials. Sixteen surface mold samples were collected from remaining building materials and on all levels of the house, including in the garage. Hardwood flooring materials could not be tested without destroying boards, but the damage was clear. GML tested several different types of materials including Sheetrock, plywood, wall studs, and OSB sheathing in the kitchen to get representative samples of materials exposed to water.

Lab Results:

Three surface samples confirmed mold growth on remaining Sheetrock in the house. Two were from the basement and one from behind one of the second floor bathtubs. The predominant molds growing on the Sheetrock were Aspergillus, Penicillium, and the infamous toxic black mold, Stachybotrys. None of the other thirteen samples described mold growth.

Recommendations:

Professional mold remediation is needed to remove contaminated Sheetrock in several areas of the basement, and all hardwood flooring on the first floor. Based on our experience in similar situations and the onsite inspection, even without testing, the conclusion was made that the hardwood flooring is contaminated. The AC system will need to be professionally cleaned. Once all the work is completed, the whole house should be cleaned using specialized, detailed cleaning procedures.

Facts/History/Observations:

Single family, two story house was converted from a one level ranch originally built in the 1960’s. A recent home inspection discovered mold on the underside of both sides of the roof, mainly on plywood sheathing. Mold was also growing on both gable ends. The attic had a functioning ridge and soffit vent system as well as one open gable vent. The second floor bathroom fan was exhausting into a soffit vent. Mold was reportedly present when the current owner purchased the house at which time they added the ridge and soffit vent system with the new roof. The cause of the mold was inadequate ventilation prior to the installation of the ridge and soffit venting system. There were no other signs of water leaks or sources of accumulated moisture.

Mold on plywood roof sheathing

Inspection Strategy:

• Visual inspection
• Moisture readings in wood materials
• Surface tape-lift sample collected from plywood roof sheathing with black mold

Lab Results:

• Mold Identification: Actively growing Cladosporium
• Classification: Cladosporium is a common, environmental mold often found in attics when there is a moisture problem

Recommendations:

It is recommended to have the attic evaluated to confirm that there is adequate ventilation and to discuss insulation, the bathroom vent, the gable vent, and any other factors that can influence mold growth development. Professional mold remediation is necessary to remove the mold growth in the attic; a homeowner or otherwise unskilled person should not do the cleaning because of the risks involved with such a project. Proper containment and decontamination procedures are needed. All insulation should be removed from the floor of the attic. A sealant should be applied to wood materials as the final remediation step in this attic.

Case Study 09027: Mold Problems in Split Level House

Facts/History:

-Split level, single family house, early 1970’s construction
-History of water problems into the lower level

• Ground water infiltration
• Lower level bathroom plumbing leak
• Water intrusion behind front steps into crawlspace
• Damp lower level—no known history of dehumidification

-Two forced hot air/central air conditioning system
-Central humidifier on one of the heating systems
-Fully carpeted—upper and lower levels
-Tenants have concerns about mold—people living in the house, including a young child, have had chronic illnesses since moving in less than a year ago.

Observations:

-Mold odor throughout the home but stronger in the lower level
-Visible mold on Sheetrock walls at the floor level in several areas

-Visible mold and rotting materials beneath the lower level stairs (storage crawlspace beneath front steps leading into house)

-Carpeting in lower level was full of dust and dirt

-HVAC systems in disrepair

• Dirt and dust inside ductwork
• Fiberglass linings inside air handlers were deteriorated and caked with dust
• Ineffective filters, very dirty
• Central humidifier loaded with visible mold

Sampling Strategy:

-Air sampling to identify mold types and levels throughout the house
-Surface sampling to identify mold types and their extent on building materials and inside the HVAC system

Lab Results:

-Air samples showed elevated mold levels in the lower level (Penicillium was the main mold)
-Basement mold spores have been migrating to the upper level through HVAC ductwork and the open stairwell
-Indoor mold levels higher than outdoors and different mold types found inside
-Mold growth was confirmed on the following surfaces:

• HVAC system components: ductwork, filter, central humidifier, inside air handler
• Sheetrock in the lower level exposed to water
• Rotting wood materials in crawlspace beneath stairs
• Lower level carpeting

Recommendations:

-Professional mold remediation to remove contaminated building materials in the lower level, including carpeting, Sheetrock, rotten wood materials, and more
-Professional HVAC cleaning, system maintenance, and upgrade

- Specialized whole house cleaning
-Identifying and resolving water issues
-Dehumidification in the lower level
-Additional GML recommendations to help prevent mold growth in the lower level