Readings of 5 to 12% are considered normal, and up to 17% is considered acceptable. Wood starts to rot and is susceptible to mold when its moisture content reaches 35 to 50%. Wood can typically hold up to 25% without showing signs of deterioration.
Relative humidity greater than 60 percent is likely to result in condensation in the building, which can lead to mold growth.
The general rule is that any moisture reading over 16% is considered damp and needs attention. If your reading is over 20%, you may need to replace the drywall entirely. The walls in your home with healthy humidity levels should have a moisture reading between 12 to 15%.
The maximum relative humidity in the test was 95%, and so the critical level for materials that did not show any mould growth during the test period was above this value. The lowest RH at which mould growth appeared was 80%.
A typical mold spore count in a closed space is 200-500 spores. A mold spore count of 1-1500 mold spores in a room is normal and safe as long as visible mold growth is not present and no water damage or excess moisture exists. It's normal that mold spores are found in almost every home.
A concentration of mold spores above 500 sp/m3 is considered high. Therefore, if your report comes up with high concentrations of mold, it will likely advise you to remediate the problem. However, it is important to note that even low concentrations of mold spores can cause health problems in some people.
Readings of 5 to 12% are considered normal, and up to 17% is considered acceptable. Wood starts to rot and is susceptible to mold when its moisture content reaches 35 to 50%. Wood can typically hold up to 25% without showing signs of deterioration.
You should be aware that a moisture reading of 0-15% is quite normal and gives no cause for concern. However, moisture readings in excess of 15% indicate the need for further inspection. Levels between 25-30% indicate that there may be water ingress, meaning that remedial work could be required.
Moisture can be the number one enemy of drywall; any good drywall service can tell you that. According to Hunker, moisture levels of about 17% mean the drywall is compromised and will need to be replaced.
Sometimes, humidity or dampness (water vapor) in the air can supply enough moisture for mold growth. Indoor relative humidity (RH) should be kept below 60 percent -- ideally between 30 percent and 50 percent, if possible. Low humidity may also discourage pests (such as cockroaches) and dust mites.
The temperature in your home
Keep doors of unheated rooms open to allow some heat into them. Ideally your home should be heated between 18 to 21 degrees Celsius, but older people, babies and people who are less mobile may need it to be warmer.
Mold will grow in your home with humidity levels over 55% or higher. It can be controlled with a dehumidifier and good ventilation. Dry walls with a moisture level of over 17% may often need to be removed and replaced by a drywall service.
The walls and flooring in every bathroom that is being used on a regular basis will have some degree of moisture present. Normal bathroom walls and floors have a general moisture reading of around 3.5 to 5.5. Anything under 3.5 is great and anything above around 7.0 should be investigated and monitored.
The real question is not whether your drywall is dry but whether the moisture level it contains is safe and appropriate. An acceptable level of moisture content is between 5% and 12%. Even a higher level may not spell disaster if not confined to a small area.
Compare the reading with the recommended moisture levels. Zero moisture is unattainable; even wood used to structure a home has some moisture. Normal values range from 7 to 13 percent moisture. Slightly higher readings may be typical for your home, but very high levels necessitate prompt action.
Every home is different, but a level between 30 and 40 per cent humidity is typically ideal for keeping your home warm and comfortable in the winter, without leaving condensation on the windows. In the summer, that level can be higher, between 50 and 60 per cent. So, how do you know your levels?
Moisture meters help detect moisture spots with possible mold growth. If your MC reading in wood is more than 20%, you may want to check these areas for mold growth. When the MC is above 20%, this is possibly where mold growth can start to happen. Humans have reason to attach negative connotations to mold.
When the relative humidity is more than 50%, moisture problems may occur. Generally, in cold winter conditions the relative humidity levels need to be low to prevent condensation and potential damage to the structure of the house and to discourage mold growth, which can cause allergies and respiratory problems.
Using a moisture meter for drywall is one of the fastest ways to test moisture in drywall. However, not just any moisture meter will do. To get accurate results, the moisture meter should have a specialized gypsum/drywall scale mode.
However, some common signs that may indicate mold exposure include: Coughing, wheezing, shortness of breath, nasal congestion, and frequent sinus infections. Rashes, itching, burning sensations, and persistent skin irritation.
Mold is an obvious health risk in any home, but investing in an air purifier can help limit your exposure. The best among them will ideally offer HEPA-level filtration, with this level of filtration being able to trap up to 99.97% of airborne particles down to 0.3 microns in diameter.
A level 3 mold remediation is when mold has spread between 30-100 square feet. When your mold contamination has spread to the size of an entire utility room, it's time to call a local mold remediation company with a good reputation in your area.