Astm f2170 rh testing inside the concrete slab the in situ rh test provides a numeric measurement of the moisture within a concrete slab using an rh sensor placed at a specific depth.
Floor measurement top of slab to top of slabs.
Slab measured across wall.
These factors can introduce a lot of moisture variability across the floor slab.
If they bead up on top of the slab it is probably contaminated.
On commercial jobs raw slabs are frequently treated with sealers which may cause adhesion problems.
Open top of wall.
Floor flatness tends to be very important for spaces where equipment must be set perfectly.
Top of slab above i e.
This vinyl type comes in a single sheet that is installed over the concrete floor.
Soffit of transfer structure slab or beam above.
Even if the builder forgot to install poly under the slab there.
Who installed your radiant floor slab.
Most residential slabs have a layer of 6 mil poly or a similar thicker vapor barrier membrane directly under the slab.
As with f l the measurements are linear and higher numbers represent a flatter floor.
Did the builder forget to install poly under the slab.
Exclude formwork intersected by slabs.
That s why builders rarely install 6 mil poly on top of a slab.
This includes backing top design and protective layers.
Because concrete likes water the drops should absorb into the slab.
Adhering to the astm standard and installing rh sensors every 1 000 square feet is the only way to go to ensure greatest testing reliability.
The calcium chloride test or mver has been shown to measure moisture conditions in the top inches of the slab only.
Do not exclude formwork intersected by beam ends.
A range of sizes and configurations are possible with wide slabs so our designers ensure that each project is individually designed for application and loadings.
To test for an incompatible product on the slab an easy method is to put a few drops of water on the slab.
Additionally because this method only takes measurements at or near the slab s surface it has many of the same drawbacks as the cacl 2 test.
We aim to reduce the weight of the slabs to bring down costs reduce transport loads and craneage where possible.
Exclude concrete at junctions with slabs of same concrete grade i e.
Wall measured through slab.
For example a floor with an f f measurement of 60 is twice as flat as a floor with an f f of 30.
No surface test tells an installer how much moisture is present deeper within the concrete which is critically important as that moisture gradient will equalize if a non permeable floor covering is installed.
Several types of vinyl flooring may work better for different concrete floors.