The words in the report, explained.

Microscopic fungi that grow on damp organic material: plasterboard, wood, wallpaper, dust. The mold itself is a network of cells (hyphae); what you see on the wall is the colony, and what you breathe are the spores and fragments it releases. Mold needs moisture, not light, which is why it appears behind wardrobes and inside walls before anyone notices.

The mold's reproductive units, a few microns across. They are in all air, indoors and out; the question an inspection asks is not whether there are spores but how many, of which species, and in what ratio to the air outside. A high indoor concentration of one species compared with outdoors points to a source inside the home.

The fine threads the body of a mold is made of. Hyphal fragments in an air sample are an important finding: unlike spores they do not blow in from outside, so they indicate an active colony breaking down inside the space being tested.

The species the public calls black mold. It grows on cellulose-rich materials that stayed wet for a long time: plasterboard after a leak, cardboard, wood. Its spores are heavy and sticky, so an air sample rarely catches them; reliable identification comes from a surface sample or from DNA in dust.

The two most common groups in Israeli homes, counted together in a microscope air sample because their spores look alike. They grow on dust, food, air conditioners and slightly damp surfaces. A high indoor count is the most frequent finding in our inspections and usually points to general humidity rather than a single leak.

A species that appears after prolonged water damage, often alongside Stachybotrys, on wet plasterboard and wood. Its presence in a sample means the material was wet for weeks rather than days, which changes the recommendation from cleaning to replacement.

The water vapour in the air as a percentage of the most that air could hold at that temperature. Above 60% for sustained periods most mold species can grow on dust and surfaces; below 50% most cannot. Warm air holds more water, so the same vapour gives a higher relative humidity in a cold corner of the room.

The temperature at which air is saturated and vapour starts condensing into droplets. Any surface in the home colder than the dew point of the air around it will get wet: a window in winter, an exterior wall behind a wardrobe, a cold water pipe. It is the bridge between "the home is humid" and "there is a wet patch exactly here".

Water that forms from the air on a cold surface, with no leak at all. The most common cause of mold in ceiling corners, around windows and behind furniture in Israeli apartments in winter. The fix is heating, ventilation and insulation, not a plumber.

Ground water climbing a wall through the capillaries of concrete and plaster, usually to about a metre. Recognised by an even wet band along the bottom of a wall, crumbling plaster and white salts. Common on ground floors, in basements and in homes on older foundations.

A place in the building envelope that conducts heat faster than its surroundings: a concrete column inside a block wall, a floor slab edge, a lintel. In winter it is the coldest point on the inner wall and therefore the first place water condenses and mold grows, usually in a straight vertical or horizontal band.

How much water the building material itself holds, as distinct from the air. Measured with a moisture meter in percent or relative units. Plasterboard above about 1% and wood above about 16% are wet enough for mold growth, even when the surface feels dry to the hand.

A pump draws a known volume of air (75 litres, say) through a cassette that traps particles on a sticky surface. The lab counts and identifies the spores under a microscope and calculates a concentration per cubic metre. An outdoor sample is always taken for comparison, because without a reference the indoor number alone says little.

Clear adhesive tape pressed onto the stain, or a swab wiped across it, sent to the lab for identification under a microscope. It answers "what is this stain" and catches species an air sample misses, such as Stachybotrys. It does not measure exposure, only presence.

The comparison between the spore concentration in a room and the concentration outdoors at the same hour. In a sound home the indoor profile resembles the outdoor one and is lower. A higher indoor concentration, or a species present indoors but not outdoors, indicates a source inside. It is the basis for interpreting every air sample.

An instrument that measures moisture inside a material. One type has pins pushed into the material to measure conductivity; the other is contactless and scans a few centimetres deep. It is used to map the edge of the wet area in a wall and find the source, which is usually not where the stain is.

A camera that shows temperature differences across a wall. A wet surface is colder because of evaporation, so a leak behind the plaster or a thermal bridge shows as a dark patch before there is a visible sign. The camera does not see water; it sees cold, so every finding is confirmed with a moisture meter.

Airborne particles up to 2.5 or 10 microns across. Our monitoring sensors measure them continuously; mold spores and hyphal fragments fall in this range, as do dust, smoke and soot. A rise alongside high humidity in a closed room is a pattern that justifies an inspection.

Gases released by materials: paint, furniture, cleaning products, and also by living mold (then called MVOC). The "musty" smell is MVOC. A VOC sensor does not detect mold by itself, but a persistent musty smell with no visible source is one of the most common reasons an inspection is booked.

An index developed at the US EPA: DNA analysis of house dust for 36 mold species by qPCR, summarised as one score. 26 of the species indicate water damage and 10 are common in every home; the score is the difference. Unlike an air sample, dust represents months rather than a moment. The panel we run identifies 15 key fungal elements.

A reduced version of ERMI that looks at five species only, the ones most associated with serious water damage. Used mainly to judge whether a remediated home is safe to return to. A score under 11 is generally considered acceptable.

A lab method that copies a DNA segment unique to each species and counts how many copies were there to begin with. It identifies a mold species even when there are no intact spores to count, and quantifies it as a number rather than a visual estimate. It is the technology behind ERMI.

Chemical compounds certain mold species secrete, such as ochratoxin A, aflatoxins and trichothecenes. They are not alive, so they remain in dust and belongings after the mold is removed. A standard mold test does not measure them; that takes chemical analysis on an LC-MS/MS instrument. Health effects depend on the compound, the concentration and the exposure, and are a matter for a physician.

An analytical instrument that separates a chemical mixture into its components and identifies each by its mass. It is how mycotoxins in dust are measured, at parts-per-billion sensitivity. Our panel covers 16 toxins in five families.

The record that travels with every sample from collection to result: who collected it, when, where, and who received it at the lab. It is what makes a report a document that holds up with an insurer, a contractor or a court, rather than an opinion.

Removal of the mold and contaminated materials and repair of the moisture source, by a contractor. We inspect and do not remediate, on purpose: whoever sells the repair should not be the one deciding whether it is needed. A follow-up test after remediation confirms concentrations are back to outdoor levels.