Floor flatness tends to be very important for spaces where equipment must be set perfectly.
Floor measurement top of slab to top of slabs.
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.
On commercial jobs raw slabs are frequently treated with sealers which may cause adhesion problems.
Exclude concrete at junctions with slabs of same concrete grade i e.
Wall measured through slab.
Because concrete likes water the drops should absorb into the slab.
The calcium chloride test or mver has been shown to measure moisture conditions in the top inches of the slab only.
This includes backing top design and protective layers.
Exclude formwork intersected by slabs.
Most residential slabs have a layer of 6 mil poly or a similar thicker vapor barrier membrane directly under the slab.
Did the builder forget to install poly under the slab.
Do not exclude formwork intersected by beam ends.
For example a floor with an f f measurement of 60 is twice as flat as a floor with an f f of 30.
As with f l the measurements are linear and higher numbers represent a flatter floor.
Several types of vinyl flooring may work better for different concrete floors.
We aim to reduce the weight of the slabs to bring down costs reduce transport loads and craneage where possible.
F f numbers can be taken for slabs on grade as well as elevated slabs.
Even if the builder forgot to install poly under the slab there.
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.
Open top of wall.
A vinyl sheet may be forgiving if your concrete slab isn t perfectly even.
This vinyl type comes in a single sheet that is installed over the concrete floor.
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.
If they bead up on top of the slab it is probably contaminated.
Soffit of transfer structure slab or beam above.
That s why builders rarely install 6 mil poly on top of a slab.
Felts understands that one dry spot in the slab doesn t mean it is ready for the finished floor.
Top of slab above i e.
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.
These factors can introduce a lot of moisture variability across the floor slab.
Who installed your radiant floor slab.
