Subfloor material: For plywood and Oriented Strand Board (OSB) subfloors, moisture content should generally be between 6% and 12%, and the subfloor should be flat with deviations typically no greater than 3/16-inch over a 10-foot span.
First, test the moisture level of the subfloor. In general, 12% moisture or above is too wet to install flooring. Ideally, it should be between 7% and 9%. Take the readings in at least 20 spots per 1,000 square feet of flooring and average the results.
According to the ASTM standards, recommended concrete moisture levels are a relative humidity (RH) of 75% or below or whatever the manufacturer of the floor covering specifies. Many manufacturers may allow for RH levels that are above 75% as some floors may be more durable than others.
The plank wood floor MC measured 6 to 7%, meaning that per the Installation Guidelines the subfloor MC range need to be between 8 to 9%, not 11 to 13%.
Carlisle Coatings & Waterproofing offers these general guidelines: Wood based sheathings (plywood, OSB) shall be at a moisture content of 19 percent or less.
A normal moisture reading for brick walls in the UK is around 13% to 16%. Anything above 17% indicates a potential issue and should be investigated. High readings may result from: Penetrating damp due to poor external maintenance. Rising damp caused by a faulty damp-proof course.
Sometimes, subfloors can be dried out from below, either from a lower level or a crawlspace. But if the water damage was too significant and there is no easy way to allow airflow to dry out your subfloor, it should be replaced.
The first way that you can fix a subfloor moisture problem is by removing the finished floor and exposing the subfloor. Make sure that an HVAC system is installed or use a dehumidifier, and then, let the subfloor dry until the moisture levels have gone down.
If excess moisture is found, the humidity of the room should also be considered. An acceptable level of indoor humidity is generally 30 to 50%, which prevents the growth of microorganisms, such as mold. Excess moisture promotes mold, mildew, fungi, bacterial growth, and possibly viruses.
Yes. Hardwood flooring is quite sensitive to moisture and it's always worth adding a moisture barrier during installation. It is a necessity with concrete subfloors and damp areas, but water-resistive underlayments should be considered with other subfloors as well.
What is an acceptable moisture reading in hardwood floors? Wood flooring installers typically want the moisture content of hardwood floorboards to be between 6% and 9%.
Most people find that a relative humidity between 30 to 60 percent is the most comfortable, with indoor humidity ideally between 30 to 50 percent.
Signs of excessive crawlspace humidity include: Wood moisture levels exceeding 20% (measured by a moisture meter) Insulation drooping or falling. Dark stains on floor joists.
You can check this quickly using a pinless moisture meter. The subfloor materials should be within 2%–4% moisture content of the floor. If they aren't, allow them to acclimate until they're within that range.
The normal moisture content of wood (or EMC) varies from 7%-19% depending on the RH in the air. If an interior location has an average RH of 40-52%, wood placed there will have an average EMC of 8-9%. This is based on a Wood Handbook: Wood as an Engineering Material chart.
No subfloor is perfectly level, but any signs of unevenness and high or low spots must be remedied. Please follow these requirements: Subfloor unevenness cannot be greater than 3/16 of an inch over a 10-foot span or 1/8 inch over a 6-foot span.
Concrete subfloor
Per the ASTM (American Standards of Testing Materials) F2170 standard, the relative humidity should be below 75% or whatever relative humidity level the flooring manufacturer specifies. Different flooring products can handle different relative humidity levels, usually varying between 75% and 90%.
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.
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.
Your floors shift or bounce when you walk on them.
If your floors begin to feel spongy, springy or bouncy, or if you notice the floorboards around you shifting when you walk on them, it could mean that it's time to replace your subfloor.
Utilising subfloor approved dehumidifiers, like inhouse dehumidifiers, can be a highly effective method for drying a wet subfloor. Additionally, specialised subfloor drying equipment, such as heat drying systems, can significantly expedite the drying process.
Taking all these factors into account, subfloor material costs can range from as low as $2.50 per square foot for plywood to as high as $10 per square foot for Amdry or Barricade. Common subfloor materials include plywood, oriented strand board (OSB), Amdry, DRIcore, Barricade, Warmboard, and concrete.
Subfloor mold often shows up as dark spots or patches under your floors. You might find it under carpets, vinyl, or laminate. The mold can look like black, green, or white marks on plywood or OSB, which are common in homes since the 1950s. A musty smell is a sign of subfloor mold.
Contact with the ground must be avoided, as rising moisture can also damage them. Boards should ideally be stored in dry conditions beneath a roof.