Frequently Asked Questions
What is Moisture/Vapor Emission?
Moisture/Vapor Emission is the movement of moisture thru concrete.
Where does it come from?
There are four possibilities as to where moisture can come from:
- Excess water added to new concrete to make it workable or pumped.
- Humidity difference between the slab and the air above the slab.
- Hydrostatic pressure (Water table is higher than the slab).
- Active source (Rain water seeping under the slab, plumbing leak, etc).
My slab is over 28 days old, how can it still be wet?
The 28 day time table is relevant for hardness (80% of designed psi) not dryness.
Why do I need to test the 3rd floor, surely there are no moisture concerns here?
Most pan filled cements are designed with light weight aggregate that act as miniature sponges plus additional water is needed in order for the cement to be pumped. This slab very well may take longer to dry out than a slab on or below grade.
How can I dry out my slab?
You can dry out your slab by conditioning the air in the room and – then you wait.
How long will it take?
On average, if the environmental conditions are 50% humidity and with an air temperature of 73 degrees, it will take one month per inch. Five inch slab will take five months.
I don’t have 5 months. What can I do?
Let us install a moisture control system today and you will be able to install your floor covering tomorrow.
It is never too early to call us. It is never to late to call us. 1-866-404-CMCI (2624)
