The efflorescence you are seeing when you lift the individual subfloor tiles is caused by minerals leaching from the concrete.
Ideal moisture sub floor house.
Humidity is the amount of water vapor in the air.
At this equilibrium moisture content emc wood will stop absorbing or shedding moisture which prevents some of the physical problems that can occur in wood flooring.
2 for plank 3 wide or more hardwood and 4 for strip 2 wide hardwood.
Two weeks ago the moisture in the subfloor was 22.
Moisture is constantly released into the atmosphere from the earth and is dispersed by the wind.
2 4 acceptable variance between top layer subfloor.
Hardwood floors the maximum subfloor moisture level will be either 12 or 13 depending upon the manufacturer.
These are the safest conditions for most types of wood between 60 and 80 degrees fahrenheit and 30 to 50 rh.
This chart highlights the ideal levels of moisture in wood at various temperatures and relative humidity rh levels.
This occurs from water that either leaks under the subfloor or from moisture within the concrete slab itself.
Today it was at 12 or 14 still.
In this chart you can see a small highlighted section.
Then the hardwood flooring moisture content must be within 2 4 of the subfloor moisture.
For all intents and purposes the ideal moisture of flooring wood will be the moisture content at which the wood reaches equilibrium with the installation environment.
This will vary from product to product.
While it s important to extract moisture and treat the top level of your wood floors it s all for naught if you don t do the same for the sub floor.
It may be made of boards laid either at right angles or diagonally across joists.
2 4 represents the acceptable level of variance between the top level of your wood floors and the subfloors.
I m using a pin tester and checking at a depth of 1 8 to 1 4.
Tile and stone flooring can be installed directly over concrete but most other flooring materials require some kind of underlayment and or a moisture barrier laid over the concrete.
Subflooring provides a base for finish flooring and also serves as a platform during construction.
When that occurs dirt and dust or other debris under the subfloor could become a substrate for mould growth.
A concrete slab makes for a very hard solid durable and often very smooth subfloor.
A week ago it was down to 12 or 14 depending where you checked.
High humidity in the home can cause serious problems with your flooring.