Mold FAQ

Why is mold dangerous?

Outside, molds fulfill an important role by breaking down materials like tree leaves. Indoors, mold, including black mold, is dangerous as it damages building materials (wet or dry rot) and releases mold spores into the air we breathe. Mold spores in our indoor air are at best an irritant that can trigger minor allergies, and at worst can cause severe and dangerous allergic responses like asthma attacks and even anaphylaxis (closing of the airway). Additionally, as a natural defense, some molds produce toxic chemicals that can cause severe reactions in people. Different people may have vastly different reactions to the same mold exposure, but no mold indoors is good. 

How do molds grow indoors?

To grow indoors molds need moisture and food. Molds will not keep growing in your walls without moisture, but are very patient and can wait dormant for years. Even the spores from a long-dry mold growth are still dangerous to humans and pets to breath.

A lot of indoor molds are similar to tiny dandelions. Molds typically have tiny white filaments, like plant roots, called hyphae that extend into whatever it’s growing on, and fruiting bodies on the surface, which is where mold spores grow, which look like tiny dandelions.

When conditions are ideal (good temperature, moisture, and food source) molds grow fast, spreading out from their hyphae “roots,” and producing spores that can be easily airborne. Mold spores in the air can float for a very long time before settling and waiting, even for years, for good growth conditions.

Do mold home test kits work?

No, the type of mold test kit sold at hardware stores and online are not useful at all. Home test kits use a petri dish that you set out in a room where mold spores may land on them and possibly grow (settling plates), they are then sent to a lab for analysis. This kind of home mold testing doesn’t tell you much, however, because there are always mold spores in the air (even in clean hospital rooms). What mold testing really needs to show you is how your indoor air compares to outdoor air, something a home mold test kit won’t show.

How to test for mold in the air?

To test for mold in the air professionals use a “spore trap” where a known volume of air is projected onto a microscope slide with a sticky coating that collects mold spores, pollen, and other tiny particles in the air. We collect mold samples indoors and also outdoors for comparison as outdoor levels of mold change considerably with the weather and seasons. After collection, the slides are sent to a lab where they are examined directly under a microscope so the tiny mold spores can be counted and classified. We compare the indoor air mold levels by type to those seen in the outdoor samples to determine if there is an abnormally high level of any mold type indoors.

Is there mold in your home or business? Get in touch with Cromwell today.

How to test mold on surfaces?

To test for mold on surfaces like drywall, professionals use a microscope slide coated with a sticky coating not unlike scotch tape. By carefully pressing the sticky slide onto a suspect growth we trap mold spores on the slide where they can be tested at a specialized lab, and the mold spores counted and identified.

This kind of mold testing is useful as it can confirm a discoloration as mold and shows you whether the mold on surfaces is the same as the mold in your air. In some cases, an indoor mold is actively growing, but not releasing mold spores, so a surface sample is needed to confirm you have mold growth in your house.

What is black mold?

Black mold is a type of mold growth typically found growing on cellulose-rich building products like sheetrock that have been saturated with water. Technically, black mold is a mold from the genus Stachybotrys (pronounced STACK EE-bot-ris).

Microscopic black mold spores are found naturally at very low levels in the outdoor air. This black mold can enter a building and settle on materials, sometimes waiting years for an opportunity to grow, such as a flood or water leak. 

How dangerous is black mold?

No molds are good in an indoor environment, but black mold (Stachybotrys sp) is considered one of the worst molds for human health. Black molds can cause allergic reactions and may produce toxins called mycotoxins. Exposure to black mold mycotoxins is typically more dangerous for the very young or very old, as well as those with asthma, allergies, or weakened immune systems. The good news is that once the black mold spores are removed people usually see their symptoms improve, so removing the source and cleaning the air are important.

What does black mold look like?

Individual black mold spores are microscopic and can’t be seen with the naked eye. Black mold growth can contain billions of spores and appears as jet black patches that can grow together into a solid black mass. Normally you will find black mold on drywall, paper, cardboard, or cotton that has been totally saturated with water for at least a few days.

Drywall is an absolutely perfect growth medium for black mold as it is two layers of cellulose (paper) with a middle layer of gypsum that holds water like a sponge.  When you see mold on your wall it is likely that the back side of that wall is even worse — it is unpainted meaning it is an easier food source for black mold, and stays wet longer than the outside part of the wall.

How to get rid of black mold?

Spraying a disinfectant on black mold or painting over mold will not get rid of it. Mold grows through the sheetrock or drywall, including the backside. To get rid of mold you need to carefully remove the sheetrock at to least two feet beyond any visible discoloration. Dealing with molds like black mold can be tricky, as disturbing them can release large amounts of mold spores into the air potentially harming you and spreading the contamination.

For growths larger than a few square feet (including the parts hidden behind a wall) you should use a professional like Cromwell Environmental to avoid making the problem worse by possibly contaminating more of the building as you disturb the mold. Professional mold remediation isolates the work area from the rest of building using HEPA filtered containment to avoid spreading the contamination. Mold remediation workers are specially trained in mold removal and the use of PPE to keep safe.

How much does mold testing and mold removal cost?

The cost of mold testing or mold remediation will depend on where the project is located, the size of the project and building, and other factors. Additional costs could be added if a project needs to be completed after hours or on a weekend such as for a retail store or occupied office. Cromwell Environmental can handle mold testing and mold remediation projects ranging from small residential to huge industrial/institutional to occupied retail offices.

Contact Cromwell for a free proposal for mold sampling and remediation across the USA and Canada.

Is mold remediation covered by insurance?

The key to whether mold remediation is covered by insurance lies with your insurance coverage and the underlaying cause of the mold. Normally, mold growth caused by sudden problems like a burst pipe, flood, or storm damage tends to be covered, while mold problems stemming from longer term issues like slow plumbing leaks, poor construction, or excess basement humidity are not. Your building insurance policy may have restrictions on how much they will pay for mold remediation, but some aspects of mold remediation can be reclassified as other covered costs for insurance purposes under certain circumstances. 

What is the difference between mold and mildew?

Technically mildews are molds. Molds and mildews are all part of the vast fungi kingdom which is thought to contain millions of separate species, mostly undescribed by science so far. Unless you are a mycologist, we usually use the term mildew or mold to describe the growth patterns of the organisms. Mildew usually refers to surface growths of fungi, and mold refers to growths that extend above the surface. We call fungi growths like those seen on your shower grout “mildew” and the fuzzy growth on your sheetrock “mold.”